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Characterization and Utilization of Cement Kiln Dusts (CKDs)
as Partial Replacements of Portland Cement
by
Om Shervan Khanna
A thesis submitted in conformity with the requirements
Table 2.5 CKD chemical oxide composition, free lime, and loss on ignition, and statistical analysis of 63 published datasets (Sreekrishnavilasam et al., 2006) 25
Table 2.6 Portland cement chemical oxide composition, total alkali content, and loss on ignition (Tennis and Bhatty, 2006) 25
Table 2.7 Mineralogical composition of U.S. CKD samples (Hawkins et al., 2004) 27
Table 2.8 Portland cement average bogue compound and Blaine fineness in 2004 (Tennis and Bhatty, 2006) 29
Table 2.9 CKD oxide composition and statistical analysis of intermittent daily samples collected from a single kiln (long-dry process) over a 3 year period (2005 – 2008) in North America (Lafarge, 2009) 34
Table 2.10 Summary of previous CKD-PC studies from literature review 61
Table 2.11 Chemical and physical composition of CKD: from CKD-PC literature review 64
Table 2.12 Chemical and physical composition of PC: from CKD-PC literature review 65
Table 2.13 Mineralogical composition of CKD: from CKD-PC literature review 67
xi
Table 2.14 Workability: from CKD-PC literature review 76
Table 2.15 Setting time: from CKD-PC literature review 81
Table 2.16 Hydration: from CKD-PC literature review 86
Table 2.17 Mortar compressive strength of CKD 1 at 0%, 5%, and 10% replacement of PC 3 as a function of time (Maslehuddin et al., 2008a) 89
Table 2.18 Compressive strength: from CKD-PC literature review 100
Table 2.19 Flexural and tensile strength: from CKD-PC literature review 106
Table 2.20 Soundness: from CKD-PC literature review 108
Table 2.21 Mortar drying shrinkage with 0%, 5%, and 10% CKD 1 replacement of PC 3 (Maslehuddin et al., 2008a) 110
Table 2.22 Drying shrinkage: from CKD-PC literature review 112
Table 2.23 Alkali-aggregate reactivity: from CKD-PC literature review 115
Table 2.24 Concrete resistivity and risk of reinforcement corrosion as specified in COST 509 (Maslehuddin et al., 2008b) 118
Table 2.25 Steel corrosion: from CKD-PC literature review 120
Table 2.26 Chloride permeability of PC 1 and PC 2 with CKD 1 replacement at 0%, 5%, 10%, and 15% (Maslehuddin et al., 2008b) 122
Table 2.27 Permeability: from CKD-PC literature review 123
Table 2.28 Freezing and thawing cycles: from CKD-PC literature review 125
Table 2.29 Sulfate resistance: from CKD-PC literature review 125
Table 3.1 CKD kiln process description 128
Table 4.1 Melting points and volatility of compounds in CKDs (Manias, 2004) 139
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Table 4.2 Chemical and select physical components of PC, CKD, and filler materials (mass %) 142
Table 4.3 Cements TI and TII mineralogical composition (mass %) 145
Table 4.4 CKD mineralogical compositions using direct test methods (mass %) 146
Table 4.5 Mineralogical composition of CKD and filler materials (mass %) 148
Table 4.6 Physical properties of all materials 152
Table 4.7 Ionic concentrations of 10:1 water to solid ratio (by mass) 159
Table 4.8 Range for chemical and physical properties of Cement TI blends at 10% and 20% replacement (Theoretical calculation, mass %) 163
Table 4.9 Range for chemical and physical properties of Cement TII blends at 10% and 20% replacement (Theoretical calculation, mass %) 164
Table 4.10 Iterative process to determine the water requirement for normal consistency of (a) Cement TI and (b) Cement TII 195
Table 4.11 Range of change in water demand for normal consistency of pastes 198
Table 4.12 Range of flow for all mortars 204
Table 4.13 Compressive strength range for CKD-PC blends as percent of PC alone 222
Table 4.14 Compressive strength range for PC-filler blends as percent of PC alone 222
Table 4.15 Autoclave expansions for (a) Cement TI and (b) Cement TII 236
Table 4.16 Range of autoclave expansions for all blends 239
Table 4.17 ASR concrete mix alkali loadings and CKD replacement levels for (a) Test Series I: Cement TI CKD blends and (b) Test Series II: Cement TII CKD blends 243
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List of Figures
Figure 2.1 Cement manufacturing process (Corish and Coleman, 1995) 9
Figure 2.2 Clinker reactions in kiln feed as a function of temperature (Manias, 2004) 12
Figure 2.3 Schematic of (a) a wet and long-dry pyroprocess and (b) a preheater/precalciner pyroprocess (with a single preheater tower) (Manias, 2004) 15
Figure 2.5 CKD and PC particle size distribution (Peethamparan et al., 2008) 30
Figure 2.6 CKD and PC particle size distribution from published literature (Sreekrishnavilasam et al., 2006) 31
Figure 2.7 Heat evolution of PC paste during hydration stages: (1) initial reaction, (2) induction, (3) acceleration, (4) deceleration, and (5) slow continued reaction (Gartner et al., 2002) 36
Figure 2.8 Relative volumes of the major compounds in the microstructure of hydrating PC pastes as a function of time (Odler, 1998) 36
Figure 2.9 Effect of firing temperature on the heat evolution of pure free calcium oxide during hydration (Shi et al., 2002) 46
Figure 2.10 Heat of hydration of cement paste determined by isothermal conduction calorimetry, (20°C and w/c = 0.44); (a) PC (b) PC + 0.5% SO3, (c) PC + 2.5% SO3 (Lawrence, 1998b) Note: Sulfate added as Gypsum (Calcium Sulfate) 51
Figure 2.11 Optimization of gypsum additions for compressive strength at different ages (Gartner et al., 2002) (Note: this PC required higher SO3 levels than normal to obtain maximum strength) 53
Figure 2.12 Effect of calcium chloride on heat development in PC (Lerch, 1944) 56
xiv
Figure 2.13 Relationship between water demand and specific surface area of PC (Sprung et al., 1985) 59
Figure 2.14 Particle size distribution of CKD 5 and PC 7 (Wang et al., 2002) 69
Figure 2.15 Paste water/binder ratio, initial set, and final set of CKD 2 as a partial substitute of PC 4 at different levels of replacement (El-Aleem et al., 2005) 70
Figure 2.16 Mortar water/binder ratio of CKD 2 as a partial substitute of PC 4 at different levels of replacement (El-Aleem et al., 2005) 71
Figure 2.17 Mortar water/binder ratio of CKD 3 as a partial substitute of PC 5 at different levels of replacement (Al-Harthy et al., 2003) 72
Figure 2.18 Hydration of pastes showing (a) evaporable water content (%), (b) free lime content (%) (calcium oxide and calcium hydroxide), and (c) chemically combined water content, as a function of time at different percentage levels of PC 4 replacement with CKD 2 (El-Aleem et al., 2005) 83
Figure 2.19 Concrete compressive strength of CKD 1 at different replacement levels of (a) PC 1 and (b) PC 2 (Maslehuddin et al., 2008b) 88
Figure 2.20 Mortar compressive strength as a function of time at different percentage levels of CKD 2 replacement of PC 4 (El-Aleem et al., 2005) 90
Figure 2.21 Concrete compressive strengths, w/b (a) 0.70, (b) 0.60, and (c) 0.50, at different percentage levels of CKD 3 replacement of PC 5 (Al-Harthy et al., 2003) 92
Figure 2.22 Concrete drying shrinkage as a function of time at different replacement levels of PC 1 with CKD 1 (Maslehuddin et al., 2008b) 109
Figure 2.23 Concrete drying shrinkage as a function of time at two different w/b ratios with 5% CKD 12 replacement of PC 12 (Wang and Ramakrishnan, 1990) 111
Figure 2.24 Concrete specimen variation of electrical resistivity with moisture content at different percentage levels of CKD 1 replacement of (a) PC 1 and (b) PC 2 (Maslehuddin et al., 2008b) 117
xv
Figure 4.1 Process flow chart for CKD chemical composition analysis 140
Figure 4.2 Particle size distribution of PC, CKD and filler. The materials are in the direction and position of the arrow: LS, D, SLX, TII, TI, A, F, C, E, B, D* 155
Figure 4.3 Particle size distribution of PC, CKD and filler between 0.1 µm and 10 µm. The materials are in the direction of the arrow: LS, SLX, C, D, B, A, F, TII, TI, E, D* 155
Figure 4.4 CKD fineness correlation between (a) Blaine fineness and particle size distribution, and (b) percentage passing 45µm sieve and particle size distribution 156
Figure 4.5 Composition of pore solution w/b 0.5 high alkali PC paste (Gartner et al., 2002) 158
Figure 4.7 Cumulative heat of hydration during initial hydrolysis (Ai) of (a) Cement TI blends and (b) Cement TII blends (w/b = 0.4, 23°C) 170
Figure 4.8 Cumulative heat of hydration during initial hydrolysis (Ai) as a function of Free CaO (%) for (a) Cement TI CKD blends and (b) Cement TII CKD blends (w/b = 0.4, 23°C) 171
Figure 4.9 Cumulative heat of hydration during initial hydrolysis (Ai) as a function of (a) sulfate content for Cement TI CKD blends and (b) alkali content for Cement TII CKD blends (w/b = 0.4, 23°C) 173
Figure 4.10 Minimum heat of hydration rate during induction period (Qi) of (a) Cement TI blends and (b) Cement TII blends (w/b = 0.4, 23°C) 175
Figure 4.11 Minimum heat of hydration rate during induction period (Qi) as a function of sulfate content for (a) Cement TI CKD blends and (b) Cement TII CKD blends (w/b = 0.4, 23°C) 176
Figure 4.12 Minimum heat of hydration rate during induction period (Qi) as a function of calcium langbeinite content for (a) Cement TI CKD blends and (b) Cement TII CKD blends (w/b = 0.4, 23°C) 177
xvi
Figure 4.13 Time of minimum heat of hydration rate during the induction period (ti) of (a) Cement TI blends and (b) Cement TII blends (w/b = 0.4, 23°C) 179
Figure 4.14 Time of minimum heat of hydration rate during the induction period (ti) as a function of total alkali content for (a) Cement TI CKD blends and (b) Cement TII CKD blends (w/b = 0.4, 23°C) 180
Figure 4.15 Main hydration peak relative to the minimum peak rate heat of hydration during the induction period (Qw-Qi) for (a) Cement TI blends and (b) Cement TII blends (w/b = 0.4, 23°C) 182
Figure 4.16 Main hydration peak relative to the minimum peak rate heat of hydration during the induction period (Qw-Qi) as a function of calcium langbeinite content for (a) Cement TI CKD blends and (b) Cement TII CKD blends (w/b = 0.4, 23°C) 184
Figure 4.17 Heat of hydration for Cement TI with (a) CKD A and LS at 10% replacements, (b) CKD C and LS at 10% replacements, (c) 0% and LS at 20% replacements, and (d) CKD B and LS at 20% replacements (w/b = 0.4, 23°C) 186
Figure 4.18 Heat of hydration for Cement TI with (a) 0% and LS at 10% replacements and (b) CKD E and LS at 20% replacements (w/b = 0.4, 23°C) 188
Figure 4.19 Heat of hydration for Cement TII with (a) 0% and LS at 10% replacements, (b) CKD C and LS at 10% replacements, and (c) CKD C and LS at 20% replacements (w/b = 0.4, 23°C) 189
Figure 4.20 The total heat generation from induction period to 7 days hydration (A7d-Ai) for (a) Cement TI blends and (b) Cement TII blends (w/b = 0.4, 23°C) 191
Figure 4.21 Water requirement for normal consistency of (a) Cement TI blends and (b) Cement TII blends 197
Figure 4.22 Correlation between Cement TI and Cement TII blends with the same CKD and replacement level for (a) all CKDs and (b) CKDs A, B, C, and D 199
xvii
Figure 4.23 Water requirement for normal consistency as a function of free lime content for (a) Cement TI CKD blends and (b) Cement TII CKD blends 200
Figure 4.24 Mortar flow of (a) Cement TI blends and (b) Cement TII blends 203
Figure 4.25 Mortar flow as a function of free lime content for (a) Cement TI CKD blends and (b) Cement TII CKD blends 206
Figure 4.26 Mortar flow as a function of (a) percentage of volume less than 30.5 µm for Cement TI CKD blends (excluding CKDs E and F) (b) percentage passing 45 µm for Cement TII blends (excluding CKDs E and F) 207
Figure 4.27 Initial set time for (a) Cement TI blends and (b) Cement TII blends 211
Figure 4.28 Initial set time as a function of the time of minimum heat rate during the induction period (ti) for (a) Cement TI CKD blends (excluding circled data points) and (b) Cement TII CKD blends 214
Figure 4.29 Initial set time as a function of soluble alkali content for (a) Cement TI blends (excluding circled data points) and (b) Cement TII blends 216
Figure 4.30 Mortar compressive strength of Cement TI blends at 1, 3, 7, 28, and 90 days (w/b = 0.485) for (a) 10% replacement and (b) 20% replacement (w/b = 0.485) 220
Figure 4.31 Mortar compressive strength of Cement TI blends at 1, 3, 7, 28, and 90 days (w/b = 0.485) for (a) 10% replacement and (b) 20% replacement (w/b = 0.485) 221
Figure 4.32 Mortar compressive strength as a function of total sulfate content for Cement TI CKD blends at (a) 1 day and (b) 3 days (w/b = 0.485) 224
Figure 4.33 Mortar compressive strength as a function of total sulfate content for Cement TII CKD blends at (a) 1 day and (b) 3 days (w/b = 0.485) 226
Figure 4.34 Mortar compressive strength at 28 days as a function of percentage passing 45 µm for Cement TI CKD blends 228
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Figure 4.35 Mortar compressive strength at 28 days as a function of calcite for Cement TII CKD blends (w/b = 0.485) 228
Figure 4.36 Expansion in limewater after 14 days for (a) Cement TI blends and (b) Cement TII blends 233
Figure 4.37 Expansion in limewater at 14 days as a function of sulfate content for (a) Cement TI CKD blends and (b) Cement TII CKD blends 234
Figure 4.38 Autoclave Expansions for (a) Cement TI blends and (b) Cement TII blends 238
Figure 4.39 Autoclave expansion as a function of free lime content (excluding data points in the circles) for (a) Cement TI CKD blends and (b) Cement TII CKD blends 240
Figure 4.40 ASR expansions over 2 years for (a) Test Series I: Cement TI CKD blends and (b) Test Series II: Cement TII CKD blends 245
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List of Appendices
Appendix A. CKD Chemical Composition Correction Calculations
Appendix B. PC and CKD TGA Analysis
Appendix C. CKD XRD Scans
Appendix D. PC, CKD-PC, and PC-Filler Properties
Appendix E. Isothermal Conduction Calorimetry Results
Appendix F. Mortar Flow Statistical Analysis
Appendix G. Mortar Compressive Strength Statistical Analysis
Appendix H. Mortar Expansion in Limewater Statistical Analysis
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List of Notation
The following notations are commonly used throughout this thesis: General
AAR Alkali-Aggregate Reaction
AASHTO American Association of State and Highway Transportation
Officials
ANOVA Analysis of Variance
ASR Alkali-Silica Reaction
ASTM American Society for Testing Materials
BS British Standard
CKD Cement Kiln Dust
CSA Canadian Standards Association
EPA Environmental Protection Agency (U.S.)
ESP Electrostatic Precipitators
GHG Greenhouse Gas
ISAT Initial Surface Absorption Test
LOI Loss on Ignition
NCHRP National Cooperative Highway Research Program
PC Portland Cement
PCA Portland Cement Association
PSD Particle Size Distribution
SCM Supplementary Cementitious Material
TCLP Toxicity Characteristic Leaching Procedure
TGA Thermal Gravimetric Analysis
XRD X-ray Diffraction
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Chemical
AFm Aluminate-Ferrite-Monosubstituted, Monosulphoaluminate, or
Monosulphate
AFt Aluminate-Ferrite-Trisubstituted or Ettringite
C3S Tricalcium Silicate or Alite
C2S Dicalcium Silicate or Belite
C3A Tricalcium Aluminate or Aluminate
C4AF Tetracalcium Aluminate Ferrite or Ferrite
CH Calcium Hydroxide
C-S-H Calcium Silicate Hydrate
Na2Oe Equivalent Na2O (Na2O + 0.658 K2O) (mass %)
1
1.0 INTRODUCTION
1.1 Background
There are currently many challenges to the utilization of by-product cement kiln dusts
(CKDs) as partial replacement of Portland cement (PC). CKDs are fine powders (CKDs
typically have between 80 and 90% passing a 90 µm sieve) that are generated during the
cement manufacturing process, then carried off in the flue gases, and subsequently
collected in baghouses or electrostatic precipitators. The portion of CKDs that are not
returned back to the cement manufacture process, or otherwise used beneficially, are
placed in stockpiles or landfills. A limited number of studies have shown that CKDs
removed from the cement manufacturing process could be used as partial replacements of
PC in the range of 5 – 15%, by mass. Although standards allow for the use of CKDs at
low levels of PC replacement, very little is known about the effects of different CKDs in
pastes, mortars, and concrete. The studies that have been published on the use of CKDs
as a partial substitute of PC often report conflicting results.
Significant amounts of CKDs are placed in landfills every year. In 2000, the Portland
Cement Association (PCA) conducted a United States (U.S.) Cement Industry survey of
92 cement plants. They reported total clinker production to be 68.8 million tonnes
(clinker is the major component of PC and is typically 90 – 95% of total cement
production). The amount of CKDs removed from the cement kiln process that year for
the same 92 cement plants was 2.8 million tonnes (4.1% of clinker production). Almost
80% of the CKDs removed from cement-producing kilns were placed in landfills, while
only approximately 20% were beneficially re-used (Hawkins et al., 2004). On a global
scale, it is estimated that approximately 30 million tonnes of CKDs are removed from the
cement manufacturing process every year (Dyer et al., 1999). Approximately 25 years
ago, the CKDs in U.S. landfills were estimated to be greater than 90 million tonnes
(Collins and Emery, 1983).
2
There are many applications of CKDs that continue to be investigated: for example, as a
component in cements and masonry products, as an agricultural/soil fertilizer, as a soil
stabilizer, as a wastewater stabilizer, as a partial replacement of soda in glass production,
as an anti-stripping agent in asphalts, and as a subgrade for highway construction (Bhatty,
1995). From the perspective of the cement industry, however, the most desirable
application of CKDs that cannot be recycled back into the process is their use as a partial
replacement of PC.
1.2 Problem Statement
Four obstacles related to CKD compositions currently inhibit their use in concrete: (i)
inadequate CKD characterization, (ii) potentially deleterious interactions between CKD
and PC, (iii) unknown interactions of CKD with mineral and/or chemical admixtures, and
(iv) CKD-PC conformance to cement and concrete standards. The focus of the thesis is to
mainly address the first and second categories. Each category is briefly discussed in this
section, however, to provide the reader with a broader understanding of the problem.
In order to understand the effects of CKDs in concrete, it is essential to have a proper
characterization of an individual CKD. Comprehensive compositional analysis of a CKD
is also important for optimization of a CKD-PC blend for use in concrete field
applications. Determining the characteristics of the CKDs used in previous CKD-PC
interaction studies was not always possible due to the incomplete compositional analysis
provided. This is likely due to the insufficient and sometimes inappropriate application of
compositional analysis procedures designed for PC to determine the composition of
CKD. CKD is a unique material that has different characteristics from PC. In comparison
to PC, CKDs typically contain higher concentrations of free lime, alkalis, sulfates,
chlorides, raw materials, and trace heavy metals (Hawkins et al., 2004).
3
CKDs can influence the interactions among the basic components of concrete (PC, water,
and aggregate). The effects of the individual components found in CKDs at elevated
concentrations in concrete are generally understood. The varying concentrations of these
components in combination with each other as found in CKDs, however, are not well
understood. Therefore, it is not clear how a particular CKD will interact as a partial
replacement of a given PC. The composition of each PC can also have unique
characteristics. A given CKD may react differently with dissimilar PCs and, therefore,
result in different effects on concrete properties. It is important to understand how the
CKD-PC interaction will impact concrete properties such as workability, hydration,
setting time, strength, volume stability, and durability for optimization of a mix design in
the field.
The impact of a CKD in concrete is not limited to its interaction with PC, aggregate, and
water. The use of supplementary cementing materials (SCMs) in concrete has been
steadily increasing over the years. The presence of a CKD could influence the
mechanisms and effectiveness of SCMs and chemical admixtures in concrete. SCMs such
as slag, fly ash, and silica fume contribute to the properties of the hardened concrete
through hydraulic and/or pozzolanic action (pozzolanic action occurs when a pozzolan
combines with calcium hydroxide to exhibit cementitious properties). It has been reported
that the high alkali and sulfate content of a CKD can act as an excellent activator for
pozzolanic materials (Konsta-Gdoutos and Shah, 2003).
Chemical admixtures are also commonly used in concrete mixtures. Chemical admixtures
can be defined as materials other than water, aggregates, and hydraulic cement that are
added immediately before or during mixing of concrete. The most prominent chemical
admixtures are used to decrease the quantity of water needed to obtain a given degree of
workability or to entrain air in order to increase the resistance of concrete to damage from
freezing (Taylor, 1997). Chemical admixtures can also be used to increase workability by
dispersion of cement in the aqueous phase of concrete and to accelerate or retard the
4
normal rate of hydration (Dodson, 1990). There is little, if any, published research on the
interaction of CKDs and PC with chemical admixtures.
Cement and concrete standards include limitations on the chloride, sulfate, and alkali
content in PC and concrete to ensure acceptable performance and durability. If it is
shown that the elevated concentrations of these components in CKDs do not compromise
performance and durability in concrete, regulatory standards may need to be modified to
allow for increased amounts of their replacement of PC. In order to allow for the use of
industrial by-products such as CKDs, there is a move away from prescriptive or
compositional standards towards performance standards. ASTM C150 allows the use of
processing additions meeting the requirements of ASTM C465 for use in the manufacture
of hydraulic cements.
1.3 Incentives and Objectives of This Study
The use of CKDs as a partial replacement of cement has the potential to substantially
reduce the environmental impact of CKD disposal and create significant cost and energy
savings to the cement industry. From an environmental perspective, CKD removal from
the cement manufacturing process leads to excessive generation of gas emissions and
increased need for land disposal sites. Partial substitution of PC with CKDs would
decrease the need for clinker production and reduce the amount of energy wasted due to
partial pyropressing of CKDs. A reduction of clinker production would also reduce
greenhouse gases that are related to fuel burning and limestone decarbonation. As
environmental concerns increase, it is also important to recognize that obtaining landfill
permits is becoming increasingly difficult. The use of CKDs as a partial replacement of
cement could help minimize the size and number of landfill disposal sites.
In addition to the environmental benefits related to CKD-PC blends, reducing the clinker
factor in cement would also create several financial benefits. First, the lifespan of the
limestone quarry and other natural resources would increase. Second, the reduction of
5
raw materials required for PC production would reduce material costs and energy
consumption related to mining, crushing, and grinding. Third, a reduction of clinker
production would reduce pyroprocess, dust collection, and landfill disposal costs. Fourth,
since the CKD is already a fine powder, there will be less energy consumption in the
finish mill to achieve the target fineness compared to the energy needed to interground
clinker. Finally, the typical transport costs for other materials used for blend cements
would not be incurred since CKD is generated on the same site as the PC. It is important
to acknowledge that the cement and concrete industry may need to incur costs related to
building and maintaining systems that allow for blending of CKD with cements that meet
quality control targets.
The study of CKD as a partial replacement of PC has been a sporadic research area for
the past 30 years. The concrete industry has been very successful in utilizing other
industrial by-products – such as slag, fly ash, and silica fume – as partial replacements of
PC. Once considered to be waste products, these SCMs are now widely used to improve
the workability, strength, and durability characteristics of concrete. Although there are
many studies that report the effects of different binary and ternary blends of CKDs with
PC, silica fume, fly ash, and/or slag, it is very difficult to make conclusions regarding
performance due to conflicting results and incomplete CKD characterizations. The
reasons for the different effects of CKD-PC blends have not been thoroughly explored.
The interaction between different CKDs and PC must be well understood before
introducing chemical admixtures and other SCMs. Understanding the CKD-PC
interactions and developing appropriate limits for specific deleterious components could
ultimately allow for the standardization and optimization of blended cements with high
replacement levels (5 – 15%, by mass) of PC with CKD in concrete, leading to both
environmental and economic benefits.
6
The first objective of this study was to compare the chemical, physical, mineralogical,
and rapid ion dissolution properties of different CKDs with PC. Since there is a lack of
proper CKD characterization in previous CKD-PC blend research, the present study aims
to identify the appropriate chemical and physical analytical methods that should be used
for CKD composition analysis. Mineralogical composition analysis is a fine complement
to chemical composition analysis since the effects of CKD elements in a CKD-PC blend
may vary depending upon the form in which they actually exist. Therefore, a method to
quantify the relative abundance of the different mineralogical phases within CKDs was
introduced. Since the availability of ions in the liquid phase greatly influences PC
hydration, the rapid ion dissolutions from CKDs compared to PC were also investigated.
The second objective was to utilize the material characterization analysis to determine the
relationships among the composition properties of CKD-PC blends and their effects on
hydration, mechanical properties, and volume stability. Paste and mortar tests were used
to assess the effects of CKDs on: (i) heat of hydration, (ii) water demand, (iii) flow, (iv)
initial setting time, (v) compressive strength, (vi) expansion in limewater, and (vii)
autoclave expansion. Regression analysis was performed where possible to examine the
relationships among CKD-PC blend properties and various independent variables.
Additionally, concrete prisms were used to evaluate the impact of CKDs on a key
* CKDs are numbered as they are referred to in subsequent discussion N.R. = Not Reported; Na2Oe = 0.658 x K2O + Na2O fCaO = free calcium oxide (free lime) and calcium hydroxide LOI = Loss on Ignition
65
Table 2.12 Chemical and physical composition of PC: from CKD-PC literature review
CaO SiO2 Al2O3 Fe2O3 MgO SO3 Na2O K2O Na2Oe fCaO LOI Blaine Author Material* Type % % % % % % % % % % % m2/kg
Maslehuddin et al. (2008b) PC 1 TI 64.35 22.0 5.64 3.80 2.11 2.10 0.19 0.36 0.33 N.R. 0.7 N.R.
Maslehuddin et al. (2008b) PC 2 TV 64.07 20.52 4.08 4.24 2.21 1.96 0.21 0.31 0.41 N.R. 0.8 N.R.
Maslehuddin et al. (2008a) PC 3 TI N.R. N.R. N.R. N.R. N.R. N.R. N.R. N.R. N.R. N.R. N.R. N.R.
El-Aleem et al. (2005) PC 4 TI 64.00 21.06 5.43 3.41 0.75 2.48 0.10 0.12 0.18 0.22 2.42 300
Al-Harthy et al. (2003) PC 5 TI 62.50 20.60 4.50 3.60 2.60 2.70 0.20 0.50 0.53 N.R. N.R. N.R.
Udoeyo and Hyee (2002) PC 6 TI N.R. N.R. N.R. N.R. N.R. N.R. N.R. N.R. N.R. N.R. N.R. N.R.
Wang et. al. (2002)
Konsta-Gdoutos et al. (2001) PC 7 TI 64.29 20.35 5.24 3.58 1.13 2.56 0.11 0.60 0.50 N.R. 1.10 N.R.
Shoaib et al. (2000) PC 8 TI 62.70 21.42 3.30 5.23 2.40 2.35 2.41 0.45 2.71 N.R. 1.22 N.R.
Dyer et al. (1999) PC 9 TI 64.90 21.10 5.00 2.70 1.60 3.30 0.30 0.60 0.69 N.R. N.R. N.R.
Batis et al. (1996) PC 10 TI 65.50 20.54 4.74 3.74 1.52 2.61 0.10 0.48 0.42 N.R. N.R. N.R.
El-Sayed et al. (1991) PC 11 TI 62.66 20.40 5.19 3.26 2.62 2.37 2.48 0.32 2.69 0.30 1.17 366
* PCs are numbered as they are referred to in subsequent discussion N.R. = Not Reported; Na2Oe = 0.658 x K2O + Na2O fCaO = free calcium oxide (free lime) and calcium hydroxide LOI = Loss on Ignition + only includes TI cements (PC 2, PC 12, PC 13, and PC 14 were excluded).
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2.5.1.2 CKD-PC Mineralogical Composition
In the majority of studies, CKD mineralogical composition data is rarely reported. The
composition of a CKD consists of unreacted phases from the raw material, partially
calcined raw feed, condensed volatiles (alkalis, chlorides, and sulfates), and/or PC clinker
particles. Since CKDs are a by-product resulting from the partial decarbonation of
limestone (CaCO3), either free lime (free CaO) or calcite is expected to be the
predominant mineralogical component. Calcium carbonate is an important mineralogical
component of CKDs that can affect CKD-PC blend properties (Bhatty, 1985a). The
reported mineralogical composition data of CKD in the literature is shown in Table 2.13.
Although there are only eight data points for calcite content, the standard deviation
reflects its variability in CKDs.
Dyer et al. (1999) used Rietveld Refinement on X-ray diffraction traces over an angular
range of 3° to 80° 2θ using commercially available software program to estimate
proportions of the compounds present in CKDs 7 and 8; this is shown in Table 2.13. This
analysis, however, cannot be used as an estimate of the actual amount of the compounds
in the CKDs due to the lack of consideration for the amorphous content. Also, CKD 7
appears to be out of the ordinary since the free calcium oxide content is 0%.
As stated in the previous section, the CKD chemical components that can affect
properties of CKD-PC blends are alkalis, sulfates, chlorides, and free lime (Bhatty,
1985a). The chemical composition, however, is not the only important factor to consider
in assessing the potential impact of using a CKD-PC blend. The physical form of these
chemical components can also be significant. For example, alkalis are known to impact
cement properties, but can behave very differently if present in different forms. Readily
soluble alkali (alkali chlorides and alkali sulfates) can impact early hydration of PC much
more significantly than alkali found in crystal structures that are less soluble. Further,
alkali chlorides and alkali sulfates impact the hydration of PC differently.
67
Table 2.13 Mineralogical composition of CKD: from CKD-PC literature review
(8) As the amount of high chloride from the CKD increased in the CKD blends, workability also increased.
Ravindrarajah (1982)
CKD 18/PC 22 P C
V V
0,25,50,75,100 0,15,25,35,45
↓ ↓
(9) Higher fineness of the CKD in comparison to the PC
(10) Increased solid volume (since the density of the CKD is lower than that of the cement).
P = Paste; M = Mortar; C = Concrete. V = varied the w/b ratio to maintain consistent workability K = constant w/b ratio, but more than one w/b ratio was tested. N.C. = No Change
77
2.5.3 Setting Time
Maslehuddin et al. (2008a) studied the setting time effect of replacing PC 3 with CKD 1
at 0%, 5%, and 10% replacement by mass in pastes, with water added to maintain a
constant normal consistency according to ASTM C187 and ASTM C191. The plain
cement paste had an initial setting time of 175 minutes and a final setting time of 256
minutes. The initial and final setting times of the paste with 5% CKD replacement were
10 minutes (6%) and 6 minutes (2%) faster than the control plain cement, respectively.
The initial and final setting times of the paste with 10% CKD replacement were 20
minutes (11%) and 18 minutes (7%) faster than the control plain cement, respectively.
The authors attributed the decrease in both initial and final setting times to the high
amounts of lime and alkalis in the CKD, which accelerate the hydration process leading
to faster setting times.
El-Aleem et al. (2005) studied the set time effect of replacing PC 4 with CKD 2 at 0%,
2%, 4%, 6%, 8%, and 10% replacement by mass in pastes, with water added to maintain
a constant normal consistency. El-Aleem et al. (2005) reported that as the CKD
replacement increases, the water demand increases and the setting time decreases. This is
contrary to what many expect since it is well known that an increase in w/b results in
longer settings times for a given paste. It is important to note that the established
influence of w/b refers to its effect on a single blend and not on blends with different
chemical/mineralogical and physical properties. As shown in Figure 2.15, the decrease of
both initial and final setting times is almost linear as a function of CKD replacement. The
initial set time decreased from approximately 135 minutes with no CKD to approximately
65 minutes with 10% CKD replacement of PC. The final set time decreased from
approximately 230 minutes with no CKD to approximately 110 minutes with 10% CKD
replacement of PC. Similar to Maslehuddin et al. (2008a), El-Aleem et al. (2005)
suggested that this was due to the high amounts of lime and alkalis in CKD.
78
Udoeyo and Hyee (2002) studied the setting time effect of replacing PC 6 with CKD 4 at
20%, 40%, 60%, and 80% replacement by mass in concrete at a w/b ratio of 0.65.
Udoeyo and Hyee (2002) reported that at a 20% CKD 4 replacement level of PC 6, the
initial setting time increased slightly from 0.72 h to 0.78 h, and the final set time
remained unchanged at 1.62 h. As the CKD 4 content increased beyond 20%
replacement, the set time increased significantly. At a very high replacement level of
80%, the initial set time was 1.33 h and final set time was 2.5 h. Udoeyo and Hyee (2002)
stated that the values of the initial and final setting times were within the relevant BS and
ASTM standards, but did not suggest possible mechanisms for the increased setting
times.
Wang and Ramakrishnan (1990) used CKD 12 at 5% cement replacement of a TIII
cement (PC 12) to determine the impact on paste and concrete setting time. The normal
consistency w/b ratio for the plain cement paste was 27.0% and the paste with CKD 11
had a w/b ratio of 28.0%. The plain cement paste had an initial setting time of 122
minutes and a final setting time of 155 minutes. The CKD-PC blend initial and final
setting times were 45 minutes (38%) and 53 minutes (34%) longer than the control plain
cement, respectively. Wang and Ramakrishnan (1990) attributed the longer setting times
of the CKD paste to the higher water content required to maintain normal consistency.
The concrete mixes were tested at three w/b ratios: 0.45, 0.52, and 0.55. The effects of
CKD on the initial and final setting times of concrete were determined by concrete
penetration resistance (ASTM C403). Both the initial and final set of the CKD-PC
concrete occurred 30 minutes later than for plain concrete (the w/b ratio for the concrete
mixes used to assess setting times was not specified). Wang and Ramakrishnan (1990)
did not suggest possible mechanisms for the increase in concrete setting times.
Ramakrishnan (1986) used CKD 12 at 5% cement replacement of a Type I cement (PC
15) to determine the impact on paste (ASTM C191) and concrete setting time (ASTM
C403). The w/b ratio for the plain cement paste was 24.5% and the paste with CKD 12
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had a w/b ratio of 25.5%. Ramakrishnan (1986) stated that the initial and final setting
times of the CKD-PC blend were longer than that of the plain cement. The author
reported the differences to be 22 minutes and 40 minutes, respectively, for initial and
final setting times. The concrete mixes were tested at a cement content of 386 kg/m3 and
w/b ratio of 0.45. Six sets of each concrete mix were batched. Ramakrishnan (1986)
reported the initial and final setting time for one of the six concrete mixes for each of the
CKD blend and plain cement. The initial and final setting times for the plain cement
concrete mix was 5 hours and 42 minutes and 7 hours and 20 minutes, respectively. The
initial and final setting times for the concrete mix with CKD 12 were 6 hours and 4
minutes and 7 hours and 48 minutes, respectively. Ramakrishnan (1986) concluded that
the setting time of the CKD pastes was slightly longer than the plain cement paste, but
the setting time of the CKD concrete mix and plain concrete mix were almost the same
(within 5%). It is important to note, however, that the concrete initial and final setting
times of the CKD concrete mixes were 22 minutes and 28 minutes, respectively, longer
than the plain concrete mix.
Bhatty (1985a) used a TI cement (PC 16) with three different CKDs (CKD 13, CKD 14,
and CKD 15) to investigate their effect on paste set time. Cement and CKD blends were
prepared by replacing 0%, 10%, and 20% of cement at a w/b ratio of 0.45. Bhatty (1985a)
stated that time of initial set was always shorter compared to cement for any blends
containing 10% CKD. Longer time of initial set was obtained for blends made with 20%
CKD 13 and 20% CKD 15, as compared to blends made with 10% of CKD 13 and 10%
of CKD 15 or to cement alone. The blend made with 20% of CKD 14 had a considerably
shorter time of initial set when compared to all other CKD blends and cement alone.
CKD 14 is characterized by high sulfate (11.10%), high free lime (21.72%), and low
chloride (0.26%) contents.
Bhatty (1984) also conducted setting time tests on pastes using five companion cements
and dusts obtained from five different cement plants. The five companion cement kiln
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dust blends are: PC 17 and CKD 13, PC 18 and CKD 14, PC 19 and CKD 15, PC 20 and
CKD 16, and PC 21 and CKD 17. For each cement kiln dust blend, the CKD replacement
of the cement was 0%, 10%, 15%, and 20% at a w/b ratio of 0.50. As the CKD
replacement level increased, the setting time for blends with CKD 13, CKD 14, CKD 16,
and CKD 17 decreased. Blends with CKD 15 had the opposite effect and increased
setting time. Bhatty (1984) concluded that the time of set generally decreased with
increased dust addition levels, although no effects of CKD chemistry were specified.
Ravindrarajah (1982) used cement pastes to assess the set time of partial and complete
replacement of cement with CKD 18 and PC 22. Cement was partially replaced by mass
at 0%, 25%, 50%, 75%, and 100%. The pastes were mixed with necessary water content
to produce a consistent workability. As the percentage of cement replacement increased,
the final setting time increased. The data shows that all samples had set within 10 hours,
which was the specified limit in the British Standard. The initial setting time also
lengthened, but the rate of increase slowed after 50% of cement had been replaced by
CKD. Ravindrarajah (1982) stated that the increased set times are opposite to what is
expected with CKDs, since a higher alkali concentration promotes shortened setting
times. The author suggested the effect of increased set time may be attributed to (i) the
physical presence of inactive particles and (ii) the kiln dust that acted as a barrier between
the cement particles and water. The nature of the suggested barrier was not specified by
the author.
A summary of the studies conducted on the setting time effects of CKD-PC blends
compared to each of the respective reference plain cement is shown in Table 2.15. The
effect of CKDs on setting times is decidedly mixed. The same CKD at different
replacement levels of a PC can have different effects on setting time. The setting time
impact of CKD is likely a function of the total composition of the CKD-PC blend.
81
Table 2.15 Setting time: from CKD-PC literature review
Author(s)
Blend Type w/b % CKD Replacement
General Effect on Setting
Time
Author Suggested Mechanism(s)
Maslehuddin et al. (2008a)
CKD 1/PC 3 P V 0,5,10 ↓
(1) High amounts of lime and alkalis in CKD accelerate hydration and lead to fast setting.
El-Aleem et al. (2005)
CKD 2/PC 4 P
V
0,2,4,6,8,10
↓
(2) High amounts of lime and alkalis in CKD accelerate hydration and lead to fast setting.
Udoeyo and Hyee (2002)
CKD 4/PC 6 C 0.65 0,20,40,60,80 ↑
Wang and Ramakrishnan (1990)
CKD 12/PC 12 P C
V N.R.
0,5 0,5
↑ ↑
(3) Higher set times in paste attributed to higher water demand due to the CKD.
(1) Physical presence of inactive particles in the kiln dust.
(2) The dust may act as a barrier between the cement particles and water.
P = Paste; M = Mortar; C = Concrete. V = varied w/b ratio to maintain consistent workability K = constant w/b ratio, but more than one w/b ratio was tested. N.C. = No Change
82
2.5.4 Hydration Kinetics
El-Aleem et al. (2005) studied the hydration behavior effect of replacing PC 4 with CKD
2 at 0%, 2%, 4%, 6%, 8%, and 10% replacement by mass in pastes with water added to
maintain a constant normal consistency. El-Aleem et al. (2005) assessed the hydration
behaviour of each mix by determining the free lime as well as evaporable water and
chemically combined water contents at 3, 7, 28, and 90 days, as shown in Figure 2.18.
The free lime was determined using the alcohol ammonium acetate method, which does
not distinguish between calcium oxide and calcium hydroxide. The evaporable water
content of the hardened paste was determined by subtracting the total water content (loss
on ignition at 1000°C of the saturated sample) from the combined water content (loss on
ignition at 1000°C for 2 hours). The authors reported that the quantity of free lime
increased with curing time due to the continuous hydration of the main cement phases
and leaching from CKD 2.
El-Aleem et al. (2005) also noted that at any given time, the quantity of free lime
increased with CKD 2 content in the blend. Continuous hydration of the cement phases
led to a decrease in evaporable water. It was reported that the evaporable water content in
pastes increased with the CKD 2 content due to the increase in mixing water and low or
no hydraulic properties of CKD 2, in comparison to the high hydraulic cement properties
of PC 4. Generally, the hydration and accumulation of hydration products mainly as
calcium silicate and sulfoaluminate hydrates cause the chemically combined water
content to decrease. The cement pastes with CKD 2 and PC 4 exhibited lower values of
combined water content than the control PC 4 paste. This indicated to the authors that the
C-S-H formed in the blends with CKD 2 and PC 4 blend is lower than that in PC 4 alone.
83
(a)
(b)
(c)
Figure 2.18 Hydration of pastes showing (a) evaporable water content (%), (b) free lime
content (%) (calcium oxide and calcium hydroxide), and (c) chemically combined water
content, as a function of time at different percentage levels of PC 4 replacement with
Wang et al. (2002) CKD 5/PC 7 (3) Higher heat evolution during initial hydrolysis.
(4) Induction period began and ended later.
(5) Higher maximum heat value at 15% CKD replacement of PC, but lower maximum heat value at 25% CKD replacement level.
(4) High alkali dissolution during initial hydrolysis cause effects (4) and (5).
(5) Optimum alkali:silica ratio at 15% CKD replacement of PC.
(6) Excessive amounts of CKD depress dissolution and retard hydration of silicates at 25% CKD replacement of PC.
Dyer et al. (1999) CKD 7/PC 9 CKD 8/PC 9
(6) Higher maximum heat value. (7) Time of maximum heat value
was delayed. (8) Higher ettringite (AFt)
content. (9) Friedel’s salt present at <
28days.
(7) Combined effect of potassium chloride and sulfate compounds could cause effects (7) and (8).
(8) Rapid ion dissolution form a dense membrane of initial hydration productcs. Higher pH, however, is less likely to promote hydration products and higher heat values.
(9) High CKD sulfate content cause effect (8). (10) High chloride content cause effect (9).
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2.5.5 Compressive Strength
Maslehuddin et al. (2008b) studied the compressive strength effect of replacing PC 1 (TI)
and PC 2 (TV) with CKD 1 at 0%, 5%, 10%, and 15% replacement by mass in concrete.
The compressive strength development after 3, 7, 14, 28, 56, and 90 days of curing were
tested, according to ASTM C39. The compressive strength development at the different
percentage levels of CKD 1 replacement of PC 1 and PC 2 is shown in Figure 2.19. For
PC 1, all of the concrete mixes with CKD 1 at 3 and 7 days had lower compressive
strength (>5%) than PC 1 alone. At all other ages, the compressive strength of 0% and
5% CKD concrete mixes with PC 1 was similar (±5%). The PC 1 concrete mixes
incorporating 10% and 15% CKD 1 had lower compressive strength (>5%) in
comparison to PC 1 alone at ages tested after 7 days. For PC 2, the compressive strength
of 0% and 5% CKD concrete mixes with PC 2 was similar (±5%) at all ages tested except
56 days (>10%). However, there was generally a decrease in compressive strength (>5%)
in the PC 2 concrete mixes with 10% and 15% CKD 1 at all ages, in comparison to PC 2
alone. The authors concluded that up to 5% CKD could be used without apprehension of
the reduction in compressive strength, despite the low compressive strength with PC 1 at
3 and 7 days and low compressive strength with PC 2 at 56 days.
88
(a)
(b)
Figure 2.19 Concrete compressive strength of CKD 1 at different replacement levels of
(a) PC 1 and (b) PC 2 (Maslehuddin et al., 2008b)
89
Maslehuddin et al. (2008a) studied the compressive strength effect of replacing PC 3 with
CKD 1 at 0%, 5%, and 10% replacement by mass in mortars. The mortar mixes had a w/b
ratio of 0.485 and were tested at 1, 3, 7, and 28 days. The compressive strength of all
CKD-PC blends was higher than PC alone at all ages, as shown in Table 2.17. At 1 day,
the blends with CKD at 5% and 10% replacement had 28% and 34% higher strength than
PC alone, respectively. At 3 days, the blends with CKD at 5% and 10% replacement had
44% and 51% higher strength than PC alone, respectively. At 7 days, the blends with
CKD at 5% and 10% replacement had 20% and 21% higher strength than PC alone,
respectively. Finally, at 28 days, the blends with CKD at 5% and 10% replacement had
5% and 11% higher strength than PC alone, respectively. At all ages, the compressive
strength increased as the quantity of CKD in the mortar mixes increased.
Table 2.17 Mortar compressive strength of CKD 1 at 0%, 5%, and 10% replacement of
PC 3 as a function of time (Maslehuddin et al., 2008a)
Average Compressive Strength (MPa)
1 day 3 day 7 day 28 day
100% PC 3 6.31 15.04 22.93 33.17
95% PC 3, 5% CKD 1 8.09 21.60 27.60 34.79
90% PC 3, 10% CKD 1 8.43 22.71 27.69 36.89
El-Aleem et al. (2005) studied the compressive strength effect of replacing PC 4 with
CKD 2 at 0%, 2%, 4%, 6%, 8%, and 10% replacement in mortars according to ASTM
C109. The w/b ratio was increased to maintain a constant flow. The mortar compressive
strength tests were conducted at 3, 7, 28, and 90 days, as shown in Figure 2.20. El-Aleem
et al. (2005) reported that the compressive strength for mortar cubes decreased slightly at
all ages with CKD content of up to 6%. Above this percentage, the compressive strength
decreased sharply. The reduction of compressive strength is suggested to be caused by:
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(i) the reduction in the cement content, (ii) an increase in the w/b ratio as the percentage
of CKD in the blend increased, (iii) an increase in free lime content in cement dust; the
higher amount of Ca(OH)2 weakened the hardened matrix, (iv) the formation of chloro-
and sulfoaluminate phases leads to the softening and expansion of the hydration products,
and (v) the porosity also increases, due to the high chloride (7.5%) and sulfate (5.10%)
content of CKD 1 (Note: the formation of these products enhances the crystallization of
hydration products leading to an opening of the pore system). El-Aleem et al. (2005)
concluded that the substitution of PC with CKD up to 6% has no significant effect on the
compressive strength of hardened mortar.
Figure 2.20 Mortar compressive strength as a function of time at different percentage
levels of CKD 2 replacement of PC 4 (El-Aleem et al., 2005)
Al-Harthy et al. (2003) investigated the compressive strength effect of using CKD 3 as a
partial replacement of PC 5 using mortars. The different mortar levels of CKD
replacement of PC by mass were 0%, 10%, 20%, 25%, and 30%. The w/b ratio of each
mortar mix varied to maintain constant flow. The mortar mixes were tested at 28 days
and showed the CKD blended strengths to be lower than the control (31 MPa). Al-Harthy
et al. (2003) attributed the lower strengths to the higher w/b ratios of the CKD blended
mortars. The 10% CKD blend had a compressive strength of 27 MPa and the 20% CKD
blend had a compressive strength of 23 MPa. It is interesting to note that the 25% CKD
blend (24 MPa) and 30% CKD blend (24 MPa) had comparable strengths to the 20%
CKD blend.
Al-Harthy et al. (2003) also used seven different concrete mixtures that were prepared
using 0 (control), 5, 10, 15, 20, 25, and 30% CKD 3 replacement by total mass of PC 5.
For each mixture, three water-binder ratios of 0.70, 0.60, and 0.50 by mass were used and
the ages tested were 3, 7, and 28 days, as shown in Figure 2.21. A major observation by
the authors was that there is generally a decrease in compressive strength with an increase
in CKD replacement for cement. The authors also observed that there is more decrease in
compressive strengths in mixes with higher w/b ratios (0.70) than in those mixes with
low w/b ratios (0.50). At 5% and 10% CKD 3 substitution for PC 5, the reductions in the
28 day compressive strength were 1.8% and 4.5%, respectively (w/b of 0.50). At higher
w/b ratio (0.60) the 28 day compressive strength reductions were more significant (12.4%
and 18% decreases in strength for 5% and 10% CKD 3 replacement of PC 5). Al-Harthy
et al. (2003) stated that CKD is not highly cementitious and the replacement of cement by
CKD will lead to less cement content and, therefore, less strength. However, small
amounts of 5% and 10% CKD substitution do not seem to have an appreciable adverse
effect on strength, especially at low w/b ratios.
92
(a)
(b)
(b)
(c)
Figure 2.21 Concrete compressive strengths, w/b (a) 0.70, (b) 0.60, and (c) 0.50, at
different percentage levels of CKD 3 replacement of PC 5 (Al-Harthy et al., 2003)
93
Udoeyo and Hyee (2002) studied the compressive strength effect of replacing PC 6 with
CKD 4 at 20%, 40%, 60%, 80%, and 100% replacement in concrete at a w/b ratio of
0.65. The tests were conducted at 1, 3, 7, and 28 days. Udoeyo and Hyee (2002) reported
that the strength decreased with an increase in CKD content at these very high
replacement levels. For example, the 28-day reduction in compressive strength compared
to the plain concrete was 7.5%, 33.2%, 71.8%, and 85.3%, respectively, for concrete with
20%, 40%, 60%, and 80% replacement levels of PC 6 with CKD 4. The strength results
suggest that CKD 4 is poorly hydraulic.
Wang et al. (2002) studied the effect of CKD 5 at partial replacement levels of PC 7 at
0%, 15%, and 25% on 28-day compressive strength with mortars at a w/b ratio of 0.50.
Wang et al. (2002) found that the compressive strength of blends with CKD and cement
increased with the CKD replacement of cement up to 15% (47.8 MPa) in comparison to
cement alone (46.3 MPa). The specimen with 25% CKD (39.4 MPa) had a much lower
compressive strength than the plain cement specimen. Wang et al. (2002) stated that it is
commonly accepted that the low hydraulic property of CKD causes the compressive
strength to decrease as the amount of CKD replacement increases. Wang et al. (2002)
also suggested that the increased strength in the specimen with 15% CKD may be
attributed to an appropriate alkalinity that increases the dissolution of silicate species and
formation of C-S-H. The authors also noted that 15% CKD replacement of PC
significantly reduces the volume fraction of pores larger than 3 µm, which may result in
improved strength.
Shoaib et al. (2000) conducted compression strength tests on concrete using CKD 6 as a
partial replacement of PC 8 at 0%, 10%, 20%, 30%, and 40% and a w/b ratio of 0.5. The
tests were conducted at one, three, and six months. The authors reported that the
compressive strength decreased with increasing amounts of CKD. Shoaib et al. (2000)
concluded that the critical value of CKD replacement of cement for compressive strength
requirements is 10%. They attributed the compressive strength loss to the reduction in
94
cement clinker, which is mainly responsible for strength development. They also
concluded that the higher concentration of chlorides present in CKD led to a reduction of
strength. It was reported that the chlorides caused the hydration products to crystallize,
which resulted in an increase in the total porosity of the hardened sample, thus reducing
the compressive strength. The authors further stated that the chloride ions take part in
chemical reactions (similar to those involving sulfate ions) and yield chloro-aluminate
hydrate 3CaO.Al2O3.CaCl2.12H2O, which can cause softening. Shoaib et al. (2000)
reported that due to the presence of alkalis, the microstructure of C-S-H phases became
heterogeneous and lowered the ultimate compressive strength.
Batis et al. (1996) used PC 10 and two CKDs (CKD 9 and CKD 10) for testing 90-day
compressive strength concrete containing CKD. Each CKD was added as a 6% partial
cement replacement, and the w/b ratio was varied at 0.65, and 0.75. At w/b ratio of 0.65
the level of 90-day compressive strength of the specimens with CKD was the same as the
plain cement specimen. At a w/b ratio of 0.75, however, the concrete specimen with CKD
9 had a 35% reduction in compressive compared to the CKD 10 concrete and plain
cement specimens. Batis et al. (1996) concluded that concrete made with CKD 10 at 6%
replacement of PC 10 exhibited as good performance as the reference concrete. In
addition, the authors noted that the incorporation of CKD 10 reduced the porosity of
concrete from approximately 14% (reference) to 10%, as measured with mercury
intrusion porosimetry (MIP) at w/b ratios of 0.65 and 0.75 and after 6 months of exposure
in NaCl. It is widely accepted that a reduction in porosity improves compressive strength.
El-Sayed et al. (1991) conducted 28-day compressive strength tests on cement pastes
consisting of PC 11 and CKD 11. The CKD was blended at 0%, 3%, 5%, 6%, 7%, and
10% replacement of cement. The w/b ratio of pastes was 0.30. El-Sayed et al. (1991)
reported that as the percentage of CKD content in the paste increased, the compressive
strength measurements decreased. The authors also reported that up to 5% CKD
95
replacement of PC was within the range of the Egyptian Standard Specifications for
Ordinary and Rapid Hardening Cement (36 MPa).
Wang and Ramakrishnan (1990) investigated the compressive strength properties of
mortar and concrete made with a binary blend consisting of 5% CKD (CKD 12) and 95%
TIII cement (PC 12). The mortar mixes had a w/b ratio of 0.485 and were tested at 1, 3, 7,
14, 28, and 90 days. The authors reported that there was no significant difference in the
compressive strengths of CKD-PC mortar and plain PC mortar specimens. Most of the
CKD-PC mortar strengths fell within plus or minus 1.4% of the strength of plain PC
mortar. The concrete mixes were tested at w/b ratios of 0.45, 0.52, and 0.55 at 1, 3, 7, and
28 days. The authors stated that most of the strengths for CKD-PC concrete were 4%
higher in the earlier tests and 3.5% lower at 28 days than for plain cement concrete.
Ramakrishnan (1986) also used CKD 12 to determine whether it was suitable as a 5%
replacement of TI cement (PC 15). Mortar and concrete testing was conducted to assess
compressive strengths. The mortar mixes had a w/b ratio of 0.485 and were tested at 1, 3,
7, 14, 28, and 90 days. Ramakrishan (1986) noted that although the difference in strength
between blended and plain cement mortar cubes was very small, the blends with CKD
nearly always had the lower strength in comparison to the plain cement. Ramakrishan
(1986), therefore, stated that the mortar specimens showed that the CKD did not possess
any cementitious property. The concrete mixes were tested at a cement content of 386
kg/m3 and w/b ratio of 0.45. Six sets of each concrete mix were batched. The concrete
mixes were tested at 1, 3, 7, 28, and 90 days. As opposed to the mortar specimens, the
concrete with CKD had equal or higher compressive strengths than the plain concrete at
all ages of testing, with the exception of the compressive strengths at 28 days.
Ramakrishan (1986) therefore concluded that there was no significant difference in the
compressive strength of blended and cement concretes. The author did not explore the
reasons for the different impact of CKD on compressive strength between mortars and
concrete.
96
Bhatty (1986) used a TI cement (PC 16) with three different CKDs (CKD 13, CKD 14,
and CKD 15) to investigate their effect on compressive strength in mortars. The amount
of CKD in each blend was fixed at 10% by mass of PC with a w/b ratio of 0.45.
Compressive strengths were determined at 1, 7, 28, and 90 days, and one year. Bhatty
(1986) reported that the blends of cement and CKD at 10% partial replacement had
higher strengths at one day, but were generally lower at 7, 28, and 90 days in comparison
to cement alone. The strengths of mortars with CKD after one year, however, were
comparable to cement alone.
Bhatty (1985a) used the same CKD (CKD 13, CKD 14, and CKD 15) and cement (PC
16) as Bhatty (1986) to conduct paste compressive strength testing. Cement and CKD
blends were prepared by replacing 10% and 20% of cement and a w/b ratio of 0.45.
Compressive strengths were determined at 1, 7, 28, and 90 days, and one year. Bhatty
(1985a) stated that all blends with CKD had similar or higher strengths compared to
cement at one day, with CKD 14 blends producing much higher strengths compared to
cement and cement blends with CKD 13 and CKD 15. Blends with CKD 15 generally
showed significantly lower strengths at later ages compared to CKD 13 and CKD 14.
Bhatty (1985a) also noted that a significantly higher strength at one day was obtained for
the blend with 10% CKD 15 compared to that with 20% CKD 15, while the other blends
were quite comparable. From seven days to one year, blends made with 10% CKD
replacement generally showed higher strengths compared to blends with 20% CKD
replacement. This study showed that the strengths are adversely affected when high alkali
chloride (potassium chloride) CKD was used. Bhatty (1985a) observed that the higher
amounts of calcium carbonate in dusts appeared to be detrimental to strength
development, but higher free lime appeared to be beneficial for strength. Blends with
CKD containing higher amounts of sulfate developed higher strength compared to blends
made with CKD containing lower amounts of sulfate. Also, when sulfate was present in
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the form of calcium sulfate (CKD 14), better strengths were obtained than when some of
the sulfate was also present in the form of alkali sulfates (CKD 13).
Bhatty (1984) also conducted compressive strength testing on pastes using five
companion cements and dusts obtained from five different cement plants. The five
companion cement kiln dust blends are: PC 17 and CKD 13, PC 18 and CKD 14, PC 19
and CKD 15, PC 20 and CKD 16, and PC 21 and CKD 17. For each CKD blend, the
CKD replacement of the PC was 0%, 10%, 15%, and 20% at a w/b ratio of 0.50. Bhatty
(1984) stated that at all ages, as the amount of CKD increased, the strength generally
decreased except with CKD 15, which consistently showed higher strength at 20%
addition compared to 10% and 15% addition levels. CKD 15 contained a much higher
chloride and alkali content and much lower sulfate content than the other CKDs. Bhatty
(1984) stated that alkali chlorides would probably behave similarly to calcium chloride,
and calcium chloride is known to increase concrete strength, especially at one to three
days curing. The author also reported that the strengths for blends containing CKD 15
were higher at one and seven days than at 28 and 90 days, when compared to cement at
the same ages. Also, strengths increased steadily with the increase in chloride level for
blends with CKD 15. The CKD-PC blends not containing CKD 15 decreased in strength
as the amount of CKD increased. This trend was more prominent in blends with CKD 16
and CKD 17, which contained moderate amounts of alkali and sulfates in the form of
alkali and calcium sulfates than in the blends with CKD 14 where the sulfate was
predominantly calcium sulfate. Bhatty (1984) concluded that the compressive strengths
for CKD blends containing 10%, 15%, and 20% were lower than cement alone. The
highest loss in strength occurred when CKDs with relatively high alkali and chloride
contents were used. However, as the amount of this CKD increased in the blend, the
strength also increased, likely due to an accelerating effect of alkali chlorides on
hydration.
98
Ravindrarajah (1982) used concrete mixes to study the compressive strength effect of
CKD 18 as a partial cement replacement of PC 22 at 1, 3, 7, 14, 28, 56, and 90 days.
Cement was partially replaced with CKD by mass at 0%, 15%, 25%, 35%, and 45%. The
total water content for each mix was different to produce a similar workability.
Ravindrarajah (1982) reported that as the percent of cement replaced by CKD increased
the compressive strength decreased, and the magnitude of strength reduction was
increased with the increase in CKD. The author cited four possible mechanisms to
explain the impact of CKD replacement of PC on compressive strength in these tests: (i)
alkalis in the CKD may modify the nature and strength of the cement hydration products,
(ii) since the CKD dust particles are finer than cement, the hydration of the cementitious
particles in the dust may occur at a faster rate than the PC. The author noted this by the
development of strength with age expressed as a percentage of its 28 day strength for the
control and CKD blended mixes. In general, the concrete with no CKD replacement
showed the lowest percentage of the 28-day strength at early ages when compared with
the CKD concrete, (iii) the portion of CKD that is not cementitious may act as a fine filler
and contribute to an increase in strength through increased compaction or provision of
nucleation sites for cement hydration, and (iv) concrete compressive strength is a
function of paste strength, aggregate strength, and aggregate-paste bond strength. The
presence of CKD causes the paste to become weaker, and as the paste strength weakens,
the aggregate-cement paste bond also weakens. Ravindrarajah (1982) concluded that
from his limited research, cement in concrete could be safely replaced by up to 15% of
CKD by mass from the perspective of short-term strength requirements.
99
A summary of the effects of studies conducted on compressive strength (f’c) with CKD-
PC blends compared to each of the respective reference plain cements is shown in Table
2.18. Although there were variations between researchers, generally the compressive
strength of samples with CKD was lower than those of the control cement samples. Some
of the suggested mechanisms for the reduction in strength are a reduction in the cement
content, an increase in the w/b ratio (for mixes that varied water to maintain the same
workability of all mixes), formation of portlandite, formation of chloro- and sulfo-
aluminate phases, higher porosity, lack of CKD cementitious value (low hydraulic
property), weakening of the paste-aggregate bond, and poor formation of C-S-H due to
alkalis from CKD. Some researchers reported that there was less of a decrease in
compressive strength between plain cement and CKD blends at lower w/b ratios. Some
researchers also noted that the CKD blends were higher at early ages and lower at later
ages than for plain cement. An appropriate alkalinity that increases the dissolution of
silicate species and formation of C-S-H and CKD acting as fine filler were suggested as
mechanisms that could cause an increase in the compressive strength of cement with
CKD as a partial substitute.
100
Table 2.18 Compressive strength: from CKD-PC literature review
Author(s)
Blend Type w/b % CKD Replacement
General Effect on f’c
Author Suggested Mechanism(s)
Maslehuddin et al. (2008b)
CKD 1/PC 1 CKD 1/PC 2
C N.R. 0,5,10,15 5% N.C 10-15% ↓
Maslehuddin et al. (2008a)
CKD 1/PC 3 M 0.485 0,5,10 ↑
El-Aleem et al. (2005)
CKD 2/PC 4 M V 0,2,4,6,8,10
↓
(1) Reduction in the cement content
(2) An increase in the w/b ratio
(3) Increase in free lime content in cement dust; the higher amount of Ca(OH)2 weakened the hardened matrix.
(4) The formation of chloro-and sulfoaluminate phases leads to the softening and expansion of the hydration products.
(5) The porosity increases due to the high chloride (7.5%) and sulfate (5.10%) content of the CKD (formation of these products enhances the crystallization of hydration products leading to an opening of the pore system).
Al-Harthy et al. (2003)
CKD 3/PC 5 M C
V K
0,10,20,25,30 0,10,20,25,30
↓ ↓
(6) More decrease in compressive strength at higher w/b ratios
(7) CKD is not highly cementitious.
Udoeyo and Hyee (2002)
CKD 4/PC 6 C 0.65 0,20,40,60,80 ↓
P = Paste; M = Mortar; C = Concrete V = varied w/b ratio to maintain consistent workability K = constant w/b ratio, but more than one w/b ratio was tested N.C. = No Change f’c = compressive strength
101
Table 2.18 (continued) Compressive strength: from CKD-PC literature review
Author(s)
Blend Type w/b % CKD Replacement
General Effect on f’c
Author Suggested Mechanism(s)
Wang et al. (2002)
CKD 5 / PC 7 M 0.50 0,15,25 15% ↑ 25% ↓
(8) Low hydraulic property of CKD causes the compressive strength to decrease.
(9) Increased strength of 15% CKD-PC blend may be attributed to an appropriate alkalinity that increases the dissolution of silicate species and formation of C-S-H.
(10) At 15% CKD replacement of PC, the reduction of volume fraction of pores larger than 3um may result in improved strength.
Shoaib et al. (1999)
CKD 6 / PC 8 C 0.50 0,10,20,30,40 ↓ (11) Loss of cement clinker which is mainly responsible for strength development
(12) CKD Cl- cause crystallization of hydration products resulting in opening of pore system of the hardened samples leading to strength loss
(13) Chloro-aluminate formation causes softening
(14) CKD alkalis cause the C-S-H phases to become heterogeneous & lowers strength
Batis et. al (1996)
CKD 9 / PC 10 CKD 10/ PC 10
C C
K K
0,6 0,6
↓ N.C.
(15) CKD 9 concrete specimen was same as control at w/b of 0.65, but at 0.75 was dramatically lower.
(16) CKD 10 concrete specimen had lower porosity (MIP) compared to the concrete specimen without CKD.
El-Sayed et al. (1991)
CKD 11 / PC 11
P
0.30 0, 3,4,5,6,7,10
↓
Wang and Ramakrishnan (1990)
CKD 12/PC 12 M C
0.485 K
0,5 0,5
N.C. N.C.
(17) Most of the CKD concrete specimens were 4% higher at early ages and 3.5% lower at 28 days than for plain concrete specimens.
Ramakrishnan (1986)
CKD 12/PC 15 M C
0.485 0.45
0,5 0,5
↓ N.C.
(18) CKD does not possess any cementitious value.
Bhatty (1986)
CKD 13/PC 16 CKD 14/PC 16 CKD 15/PC 16
M M M
0.45 0.45 0.45
0,10 0,10 0,10
1d ↑, rest ↓ 1d ↑, rest ↓ 1d ↑, rest ↓
P = Paste; M = Mortar; C = Concrete V = varied w/b ratio to maintain consistent workability K = constant w/b ratio, but more than one w/b ratio was tested N.C. = No Change f’c = compressive strength
102
Table 2.18 (continued) Compressive strength: from CKD-PC literature review
Author(s)
Blend Type w/b % CKD Replacement
General Effect on f’c
Author Suggested Mechanism(s)
Bhatty (1985a)
CKD 13/PC 16 CKD 14/PC 16 CKD 15/PC 16
P P P
0.45 0.45 0.45
0,10,20 0,10,20 0,10,20
1d ↑, rest ↑↓ 1d ↑, rest ↑↓ 1d ↑, rest ↑↓
(19) High alkali chloride (KCl) in CKD reduces f’c.
(20) High calcium carbonate in CKD reduces f’c.
(21) Higher free lime in CKD increases f’c.
(22) Blends with CKD containing higher amounts of sulfate developed higher strength compared to blends made with CKD containing lower amounts of sulfate.
(23) When sulfate was present in the form of calcium sulfate (CKD 14), better strengths were obtained than when some of the sulfate was also present in the form of alkali sulfates (CKD 13).
(24) Strengths increased steadily with increase in chloride level for blends with CKD 15.
(25) The CKD-PC blends not containing CKD 15 decreased in strength as the amount of CKD increased. This trend was more prominent in blends with CKD 16 and CKD 17 which contained moderate amounts of alkali and sulfates in the form of alkali and calcium sulfates than in the blends with CKD 14 where the sulfate was predominantly calcium sulfate.
(26) The highest loss in strength occurred when CKD with relatively high alkali and chloride contents were used. However, as the amount of this CKD increased in the blend, the strength also increased, likely due to an accelerating effect of alkali chlorides on hydration (acting similar to calcium chloride).
Ravindrarajah (1982)
CKD 18/PC 22 C V
0,15,25,35,45
↓
(27) Alkalis may modify hydration products.
(28) CKD may act as a fine filler. (29) CKD presence weakens
paste and aggregate-paste bond.
P = Paste; M = Mortar; C = Concrete V = varied w/b ratio to maintain consistent workability K = constant w/b ratio, but more than one w/b ratio was tested N.C. = No Change f’c = compressive strength
103
2.5.6 Flexural and Tensile Strength
Al-Harthy et al. (2003) investigated the flexural strength effect of using CKD 3 as a
partial replacement of PC 5 using concrete. Al-Harthy et al. (2003) used seven different
concrete mixtures that were prepared using 0 (control), 5%, 10%, 15%, 20%, 25%, and
30% CKD 3 replacement by total mass of cement. For each mixture, three water-binder
ratios of 0.50, 0.60, and 0.70 by mass were used (the age at which the specimens were
tested was not specified but it is assumed that it was at 28 days). Flexural strength
measurements were determined using a two-point loading system. Toughness values,
which measure the ability of a material to absorb energy up to fracture, were calculated
based on the area under the stress-strain diagram. Similar to the effects on compressive
strength, the authors stated that the flexural strength and toughness values decreased with
an increase in CKD replacement for cement but at 5% and 10% replacement levels did
not have an appreciable adverse effect (especially at low w/b ratios). Al-Harthy et al.
(2003) attributed the reduction in flexural strength and toughness values to a reduction in
the cement content in the blends as the amount of CKD increased.
Udoeyo and Hyee (2002) studied the split tensile strength and modulus of rupture effects
of replacing PC 6 with CKD 4 at 20%, 40%, 60%, 80%, and 100% replacement in
concrete at a w/b ratio of 0.65. The tests were conducted at 1, 3, 7, and 28 days. Similar
to the results of compressive strength, Udoeyo and Hyee (2002) reported that the split
tensile strength and modulus of rupture decreased with an increase in CKD content. The
reduction in split tensile strength compared to the plain concrete was approximately 24%,
48%, 65%, and 90%, respectively, for concrete with the very high 20%, 40%, 60%, and
80% replacement levels of PC 6 with CKD 4. The reduction in modulus of rupture
compared to the plain concrete was approximately 18%, 70%, and 90%, respectively, for
concrete with 20%, 40%, and 60% replacement levels of PC 6 with CKD 4. Udoyeo and
Hyee (2002) did not suggest possible mechanisms for CKD-PC effects on split tensile
strength and modulus of rupture.
104
Wang et al. (2002) studied the effect of CKD 5 at partial replacement levels of PC 7 at
0%, 15%, and 25% on 28-day flexural strength with mortars at a w/b ratio of 0.50. Wang
et al. (2002) found that the flexural strength of blends with CKD and cement increase
with the CKD replacement of cement up to 15% (8.5 MPa) in comparison to cement
alone (8.2 MPa). The specimen with 25% CKD (7.6 MPa) had a much lower flexural
strength than the plain cement specimen. Wang et al. (2002) stated that the increased
strength in the specimen with 15% CKD may be attributed to an appropriate alkalinity
that increased the dissolution of silicate species and formation of C-S-H. Wang et al.
(2002) also reported that 15% CKD replacement of PC significantly reduced the volume
fraction of pores larger than 3 µm, which may result in improved strength.
Shoaib et al. (2000) conducted splitting tensile strength tests on concrete using CKD 6 as
a partial replacement of PC 8 at 0%, 10%, 20%, 30%, and 40% at a w/b ratio of 0.5. The
tests were conducted at one, three, and six months. The authors reported a gradual
decrease in the splitting tensile strength for all cylinders of concrete samples as the
amount of CKD increased. The reduction in tensile strength was attributed to the lower
bond strength between the aggregate and paste. Shoaib et al. (2000) stated that as the
amount of CKD increased in the paste, the bond strength between the aggregate and the
paste decreased.
Wang and Ramakrishnan (1990) studied the splitting tensile and flexural strength
properties of binary blends consisting of 5% CKD (CKD 12) and 95% Type III cement
(PC 12). The splitting tensile strength mortar mixes had a w/b ratio of 0.485 and were
tested at 1, 3, 7, 14, 28, and 90 days. The 14-day tensile strength of the CKD mortar was
10% higher than for the plain cement mortar. At 28 and 90 days, however, there was no
significant difference in the tensile strengths of the plain cement and CKD-PC specimens.
The flexural strength concrete mixes were tested at w/b ratios of 0.45, 0.52, and 0.55 at 1,
3, 7, and 28 days. Wang and Ramakrishnan (1990) stated that the results of flexure
strength tests of concrete specimens with CKD were within a range of ±4% of those of
105
the plain cement concrete and, therefore, not significant. Wang and Ramakrishnan (1990)
did not suggest possible mechanisms for CKD-PC effects on split tensile and flexural
strength.
Ramakrishnan (1986) studied the mortar splitting tensile and concrete flexural strength
properties made with a binary blend consisting of 5% CKD (CKD 12) and 95% TI
cement (PC 15). The splitting tensile strength mortar mixes had a w/b ratio of 0.485 and
were tested at 1, 3, 7, 14, 28, and 90 days. Ramakrishnan (1986) reported that for most of
the CKD-PC mortar splitting tensile strengths were lower than the corresponding plain
cement mortar strengths. The flexural strength concrete mixes were tested at a w/b ratio
of 0.45 at 1, 3, 7, and 28 days. Ramakrishnan (1986) reported no significant difference in
flexural strength between concretes containing CKD and plain concrete.
Ravindrarajah (1982) used concrete mixes to study the flexural and tensile strength
effects of CKD 18 as a partial cement replacement of PC 22 at 1, 3, 7, 14, 28, 56, and 90
days. Cement was partially replaced with CKD by mass at 0%, 15%, 25%, 35%, and
45%. The total water content for each mix was varied to produce similar workability.
Ravindrarajah (1982) also conducted tests to determine the flexural and tensile strengths.
As in the compressive strength test results, the flexural and tensile strengths decreased
with increased replacement of cement with CKD.
A summary of the studies conducted on the flexural and splitting tensile effects of CKD-
PC blends compared to the referenced plain cement is shown in Table 2.19. Generally,
the flexural and tensile strength effects of samples with CKD were lower than those of
the control cement samples, which is similar to the compressive strength effects. Many of
the suggested mechanisms for the reduction in flexural and split tensile strengths were the
same as the mechanisms for the reduction in compressive strength. The most commonly
suggested mechanism was the weakening of the aggregate-paste bond due to the presence
of CKD.
106
Table 2.19 Flexural and tensile strength: from CKD-PC literature review
Author(s)
Blend Type
w/b % CKD Replacement
General Effect on f’t
Author Suggested Mechanism(s)
Al-Harthy et al. (2003)
CKD 3/PC 5 C K 0,10,20,25,30
↓
(1) Reduction in the cement content.
(2) Less effect at low w/b ratios.
Udoeyo and Hyee (2002)
CKD 4/PC 6 C 0.65 0,20,40,60,80 ↓
Wang et al. (2002)
CKD 5/PC 7 M 0.50 0,15,25 15% ↑ 25% ↓
(3) Increased strength 15% CKD specimen may be attributed to an appropriate alkalinity that increased the dissolution of silicate species and formation of C-S-H.
(4) At 15% CKD replacement of PC, the reduction of volume fraction of pores larger than 3um may result in improved strength.
Shoaib et al. (1999)
CKD 6/ PC 8 C 0.50 0,10,20,30,40 ↓ (5) Weaker aggregate-paste bond as CKD content increases.
Wang and Ramakrishnan (1990)
CKD 12/PC 12 M C
0.485 K
0,5 0,5
↑ N.C.
Ramakrishnan (1986)
CKD 12/PC 15 M C
0.485 0.45
0,5 0,5
↓ N.C.
Ravindrarajah (1982)
CKD 18/PC 22 C V 0,15,25,35,45
↓
(6) Alkalis may modify hydration products.
(7) CKD may act as a fine filler. (8) CKD presence weakened paste
and aggregate-paste bond.
P = Paste; M = Mortar; C = Concrete. V = varied w/b ratio to maintain consistent workability f’t = flexural and/or tensile strength K = constant w/b ratio, but more than one w/b ratio was tested. N.C. = No Change
2.5.7 Volume Stability
2.5.7.1 Soundness
Maslehuddin et al. (2008a) studied the soundness effect of replacing PC 3 with CKD 1 at
0%, 5%, and 10% replacement by mass in pastes using autoclave expansion (ASTM
C151). The PC alone, PC with 5% CKD replacement, and PC with 10% CKD
replacement were 0.0075%, 0.0130%, and 0.3730%, respectively. Although the CKD-PC
blends had higher expansions than PC alone and increased as the percentage of CKD
replacement increased, the autoclave expansions were below the 0.80% allowed by
ASTM C150.
107
Bhatty (1986) used a Type I cement (PC 16) with three different CKD (CKD 13, CKD
14, and CKD 15) to investigate the effect on autoclave expansion (ASTM C151). The
amount of CKD in each paste was fixed at 10% by mass of PC, with a w/b ratio of 0.45.
Bhatty (1986) stated that the type of CKD used in the binary blend influenced the
autoclave expansion. Bhatty (1986) reported that the CKD-PC blend with CKD 14
showed autoclave expansion comparable to cement alone but higher expansions were
noted for CKD 13 and CKD 15. Bhatty (1986) also noted that each CKD-PC blend
autoclave expansion was well below the ASTM C150 specification of 0.80%. Bhatty
(1986) generally noted that when binary, ternary, and quaternary blends were made from
PC 16, the three different CKD, fly ash and slag – the blends containing CKD 15 (a high
chloride dust) generally produced higher autoclave expansions than blends with CKD 14,
which contained high sulfate.
Ravindrarajah (1982) used cement pastes to determine the soundness of PC-CKD blends
using the Le Chatelier apparatus (EN 196-3). PC 22 was partially replaced with CKD 18
by mass at 0%, 25%, 50%, 75%, and 100%. The total water content for each mix was
varied to produce similar workability. As the CKD percentage increased, so did the
expansion of the samples. This was attributed to the higher level of free lime in the CKD
in comparison to cement. Although the level of expansion was well within the range of
the British Standard, the expansion was much higher than that of cement.
A summary of the studies conducted on the soundness of CKD-PC blends compared to
each of the respective reference plain cements is shown in Table 2.20. High free lime,
sulfate, and chloride contents in the CKDs were attributed to the increased autoclave
expansions.
108
Table 2.20 Soundness: from CKD-PC literature review Author(s)
Blend Type w/b % CKD Replacement
General Effect on Soundness
Author Suggested Mechanism(s)
Maslehuddin et al. (2008a)
CKD 1/PC3 P V 0,5,10 ↓
Bhatty (1986)
CKD 13/PC 16 CKD 14/PC 16 CKD 15/PC 16
P P P
0.45 0.45 0.45
0,10 0,10 0,10
↓ ↓ ↓
(1) High chloride CKD generally produced higher autoclave expansions than high sulfate CKD (includes mixes with slag, and fly ash).
Ravindrarajah (1982)
CKD 18/PC 22 C V
0,15,25,35,45
↓
(2) High CKD free lime content.
P = Paste; M = Mortar; C = Concrete. V = varied w/b ratio to maintain consistent workability N.C. = No Change
2.5.7.2 Drying Shrinkage
Maslehuddin et al. (2008b) studied the drying shrinkage effect of replacing PC 1 (TI) and
PC 2 (TV) with CKD 1 at 0%, 5%, 10%, and 15% replacement by mass in concrete. The
drying shrinkage strain after 3, 7, 14, 28, 56, and 90 days of curing were tested, according
to ASTM C157. The drying shrinkage strain at the different percentage levels of CKD 1
replacement of PC 1 is shown in Figure 2.22. For PC 1, the highest shrinkage strain at all
ages was with the 15% CKD 1 concrete specimens followed by the concrete specimens
with 10% and 5% CKD 1, respectively. The 5% CKD 1 concrete specimens with PC 1,
however, were only marginally higher (<5%) than the concrete specimens without CKD
1. Although the test results were not provided for PC 2 concrete specimens, it was
reported that the initial shrinkage strain in the concrete specimens with CKD 1 was more
than that in the concrete specimens without CKD 1. After 90 days, however, the
shrinkage strain of 0%, 5%, and 10% concrete specimens with PC 2 was more or less
similar while that of 15% CKD 1 concrete specimens with PC 2 was significantly higher
than that of the other concrete specimens with PC 2.
109
Figure 2.22 Concrete drying shrinkage as a function of time at different replacement
levels of PC 1 with CKD 1 (Maslehuddin et al., 2008b)
Maslehuddin et al. (2008a) studied the drying shrinkage effect of replacing PC 3 with
CKD 1 at 0%, 5%, and 10% replacement by mass in mortars, according to ASTM C157.
The w/b ratio for each mortar mix was adjusted to maintain a constant flow. The w/b
ratios, however, were not reported. Drying shrinkage tests were conducted at 7, 14, 21,
28, 45, 60, and 75 days, as shown in Table 2.21. The drying shrinkage of mortar mixes
with 5% CKD ranged between 19% and 43% higher drying shrinkage than that of the
mortar mix with PC alone for the ages tested. The drying shrinkage of mortar mixes with
10% CKD ranged between 38% and 68% higher drying shrinkage than that of the mortar
mix with PC alone for the ages tested.
110
Table 2.21 Mortar drying shrinkage with 0%, 5%, and 10% CKD 1 replacement of PC 3
(Maslehuddin et al., 2008a)
Average drying shrinkage (%)
7 days 14 days 21 days 28 days 45 days 60 days 75 days
100% PC 3 0.0380 0.0528 0.0620 0.0694 0.0739 0.0811 0.0847
(1) As the amount of CKD in the blends increased, expansion also increased.
(2) Water soluble alkali showed a more meaningful relationship with expansion than did total alkali with respect to 0.60% alkali limit for CKD-PC blends.
(3) Blends with CKD 15 produced lower expansion despite having the same alkali contents as blends containing CKD 16. This is likely due to the fact that a major portion of the alkali in CKD 15 is present as a chloride salt.
(4) CKD 14 blends had similar water soluble alkali content to blends made with CKD 13 but showed much higher expansion compared to the latter.
(5) Differences in expansion of blends containing similar alkali contents can be attributed to the difference in chemical composition of cements and dusts and to the type of alkali compounds present in these materials.
(6) CKD is not the only material in a binary blend that can influence alkali-aggregate expansion. Different cements with the same kiln dust can produce different expansion not only due to differences in alkali content but other compositional variations as well
P = Paste; M = Mortar; C = Concrete N.C. = No Change.
116
2.5.8.2 Steel Corrosion
Maslehuddin et al. (2008b) studied the electrical resistivity effect of replacing PC 1 (Type
I) and PC 2 (Type V) with CKD 1 at 0%, 5%, 10%, and 15% replacement by mass in
concrete. Since electrical resistivity is a function of moisture content in the concrete,
resistance measurements were conducted at varying water content in the specimens. The
specimen was initially saturated in water for 28 days and afterward the electrical
resistivity was measured. The specimen was then allowed to dry and the electrical
resistivity measurements were taken periodically. Ultimately, the specimen was oven-
dried at 110°C and the moisture content determined. The electrical resistivity after 28
days (water curing) at the different percentage levels of CKD 1 replacement of PC 1 and
PC 2 was plotted against the moisture content, as shown in Figure 2.24. The electrical
resistivity decreased with increasing moisture content. The authors reported that the
electrical resistivity of PC 1 concrete mixes with CKD 1 at 0%, 5%, and 10% was not
significantly different. However, there was a significant decrease in electrical resistivity
of PC 1 concrete mixes with CKD 1 at 15%. For PC 2, the electrical resistivity decreased
significantly for all concrete specimens with CKD, in comparison to the concrete
specimens without CKD. The authors suggested that the decrease in electrical resistivity
due to the partial substitution of CKD 1 for PC2 in the concrete specimens may be
attributed to an increase in free chloride ions. The higher presence of free chloride ions in
PC2 concrete specimens with CKD in comparison to PC 1 concrete specimens with CKD
is possibly due to PC 2 having low-chloride binding properties (lower C3A content)
compared to PC 1. The authors used an electrical resistivity classification system to
assess the risk of reinforcement corrosion, as shown in Table 2.24. At a moisture content
of approximately 3%, the electrical resistivity of PC 1 and PC 2 concrete specimens with
and without CKD was in the range of approximately 25 – 50 kΩ.cm. Therefore,
according to Table 2.24, at approximately 3% moisture content the risk of steel
reinforcement corrosion for all of the concrete specimens is of moderate intensity.
117
(a)
(b)
Figure 2.24 Concrete specimen variation of electrical resistivity with moisture content at
different percentage levels of CKD 1 replacement of (a) PC 1 and (b) PC 2 (Maslehuddin
et al., 2008b)
118
Table 2.24 Concrete resistivity and risk of reinforcement corrosion as specified in COST
509 (Maslehuddin et al., 2008b)
Concrete resistivity (kΩ cm) Risk of reinforcement corrosion
<10 High
10-50 Moderate
50-100 Low
>100 Negligible
Konsta-Gdoutos et al. (2001) completed corrosion tests on mortar specimens using CKD
5 as a partial replacement of PC 7 at 0%, 15%, and 25% by mass. The mortar w/b ratio
was 0.50 and was mixed in accordance with EN 196-1. Mortar specimens of 75 x 75 x
300 mm were prepared and reinforced centrally with a 12M steel bar and a 12.7 mm
cover. They were cured for seven days in a curing room. To accelerate corrosion of the
embedded steel the specimens were immersed half way in a 5% (by mass) NaCl solution.
The results were interpreted according to ASTM C876 criteria for corrosion of steel in
concrete. The corrosion potential of the binary blends was monitored three times per
week. The half cell potential technique was used to measure the risk of corrosion. The
corrosion potentials observed for the CKD-PC blends suggest that more than 15% CKD
replacement of PC accelerates corrosion. This is possibly due to the introduction of
chloride ions in the mix incorporated in the CKD.
Batis et al. (1996) used PC 7 and 2 CKDs (CKD 8 and CKD 9) for testing steel corrosion
of concrete containing CKD. Each CKD was added as a 6% partial cement replacement
at three w/b ratios: 0.50, 0.65, and 0.75. Each concrete test specimen was reinforced with
steel bars and immersed in 3.5% by mass NaCl solution 5 cm from their bottom. The free
upper section of rebars were connected to copper cable and covered with epoxy resin.
The corrosion potential was measured every seven days. Batis et al. (1996) reported that
119
the blends with CKD 9 had improved corrosion resistance in comparison to the reference
mix. The blends with CKD 8 had reduced corrosion resistance in comparison to the
reference mix. The protective behavior of CKD 9 against corrosion is attributed to its
fineness and relatively higher alkalinity. Batis et al. (1996) also noted that CKD 8 had
double the chloride content and three times higher sulfate content compared to CKD 9.
The elevated chloride and sulfate ion contents accelerated the corrosion rate in the
concrete specimens made with CKD 8 at all w/b ratios.
El-Sayed et al. (1991) conducted steel corrosion tests on cement pastes and mortars
consisting of PC 11 and CKD 11. The tests were used to determine the potential level of
CKD replacement in pastes and mortars without impairing the passivity of the embedded
steel. The CKD was blended at 0%, 3%, 5%, 6%, 7%, and 10% replacement of cement.
The w/b ratio was 0.30 for pastes and 0.60 for mortars. For both pastes and mortars, as
the amount of CKD increased the passivity of steel decreased. El-Sayed et al. (1991)
determined that the steel passivity was maintained at an acceptable level up to 5% CKD
by mass of cement. The authors attributed the 5% CKD level of corrosion protection
from aggressive sulfate and chloride ions in the mix to the high hydroxide (OH-) content
that develops during hydration as a result of the CKD. El Sayed et al. (1991) concluded
that the OH- helped in maintaining the passive oxide layer that protected the steel.
A summary of the studies conducted on the steel corrosion of CKD-PC blends compared
to each of the respective reference plain cement is shown in Table 2.25.
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Table 2.25 Steel corrosion: from CKD-PC literature review Author(s)
Blend Type w/b % CKD Replacement
General Effect on Steel
Corrosion
Author Suggested Mechanism(s)
Maslehuddin et al. (2008b)
CKD 1/PC 1 CKD 1/PC 2
C N.R. 0,5,10,15 ↑ (1) Decrease in electrical resistivity (higher risk of steel reinforcement corrosion) may be due to presence of free chloride ions from CKD
Konst-Gdoutos et al. (2001)
CKD 5/PC 7 M 0.50 0,15,25 ↑ (2) More than 15% CKD replacement of PC accelerated corrosion possibly due to the introduction of CKD chloride ions.
Batis et. al (1996)
CKD 9 / PC 10 CKD 10/ PC 10
C C
K K
0,6 0,6
↑ ↓
(3) Protective behavior of CKD 10 against corrosion was partially attributed to its higher fineness.
(4) Protective behavior of CKD 10 was partially attributed to its relatively higher alkalinity.
(5) CKD 9 had elevated chloride and sulfate ion contents (compared to CKD 10) – accelerated the corrosion rate.
El-Sayed et al. (1991)
CKD 11/ PC 11
P M
0.30 0.60
0,3,4,5,6,7,10 0,3,4,5,6,7,10
↑ ↑
(6) Corrosion protection from aggressive sulfate and chloride ions in the mix was attributed to the high hydroxide (OH-) content that developed during hydration as a result of the CKD. The OH- helped in maintaining the passivation film that protected the steel.
P = Paste; M = Mortar; C = Concrete. K = constant w/b ratio, but more than one w/b ratio was tesed. N.R. = Not Reported
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2.5.8.3 Permeability
Maslehuddin et al. (2008b) studied the chloride permeability effect of replacing PC 1
(Type I) and PC 2 (Type V) with CKD 1 at 0%, 5%, 10%, and 15% replacement by mass
in concrete, as shown in Table 2.26. The chloride permeability was measured after 28
days of curing, according to ASTM C1202. The measure of chloride permeability (values
in Coulombs) increased with an increase in the CKD replacement of PC. At 5% CKD
replacement, the increase in coulomb measurement increased by 6% for PC 1 and 1% for
PC 2. At 10% CKD replacement, the increase in coulomb measurement increased by
16% for PC 1 and 13% for PC 2. At 15% CKD replacement, the increase in coulomb
measurement increased by 62% for PC 1 and 23% for PC 2. As per ASTM C1202, the
PC 1 concrete specimens with 0%, 5%, and 10% CKD were within the low range for
chloride permeability while the 15% CKD was in the moderate range. The chloride
permeability of the PC 2 concrete specimens with and without CKD replacement was in
the moderate chloride permeability classification. The author suggested that the increased
chloride content of the CKD may lead to a decrease in the electrical resistivity of
concrete which is reflected in an increase in chloride permeability. As the content of
CKD increases, more free chloride ions are liberated and cause the measure of chloride
permeability to increase.
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Table 2.26 Chloride permeability of PC 1 and PC 2 with CKD 1 replacement at 0%, 5%,
10%, and 15% (Maslehuddin et al., 2008b)
Al-Harthy et al. (2003) used sorptivity (a measure of the capacity to absorb) and the
initial surface absorption test (ISAT) to measure the permeability characteristics of
different mortar samples containing CKD. Durability of mortar and concrete largely
depends on the ease with which fluids can enter and move through the material,
commonly known as permeability. Mixtures were prepared using CKD 3 at 0%, 10%,
20%, 25%, and 30% replacement level of PC 5 by mass. Al-Harthy et al. (2003)
gradually added water to each mix to maintain the same workability. Al-Harthy et al.
(2003) stated that the sorptivity and ISAT measurements both showed that the sorptivity
of mortar decreased with incorporation of CKD in the mortar mixtures. They further
noted that since sorptivity is a function of mixture strength, the higher the strength the
lower the sorptivity values. The use of CKD improved absorption properties and
therefore, can enhance durability. The authors attributed the lower sorptivity values to the
very fine particles of CKD, but did not elaborate on the nature of this mechanism. It is
assumed that the very fine particles could provide nucleation sites for enhanced cement
hydration and/or act as fine filler material between the cement grains.
A summary of the study conducted on the steel permeability effects of CKD-PC blends
compared to the respective reference plain cement is shown in Table 2.27.
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Table 2.27 Permeability: from CKD-PC literature review
Author(s)
Blend Type w/b % CKD Replacement
General Effect on
Permeability
Author Suggested Mechanism(s)
Maslehuddin et al. (2008b)
CKD 1/PC 1 CKD 1/PC 2
C N.R. 0,5,10,15 ↑
(1) Increase in coulomb measured permeability may be due to presence of free chloride ions from CKD
Al-Harthy et al. (2003)
CKD 3/PC 5 M
V
0,10,20,25,30
↓ (2) Very fine particles of CKD.
P = Paste; M = Mortar; C = Concrete. V = varied w/b ratio to maintain consistent workability. N.R. = Not Reported
2.5.8.4 Freezing and Thawing
Batis et al. (1996) used PC 10 and two CKDs (CKD 9 and CKD 10) to study rapid
freezing and thawing resistance of concrete containing CKD. Each CKD was added as a
6% partial cement replacement at three w/b ratios: 0.50, 0.65, and 0.75. The concrete test
specimens were placed in a freezing and thawing test chamber and exposed to a
continuous 24-cycle with the following conditions: from 35ºC to -35ºC in three hours,
after that the temperature was kept constant at -35ºC for 3 hours, then it increased to 35ºC
at which it stayed for 1 hour. Each complete cycle lasted eight hours for a total of three
times per day. The mass loss of the specimens was measured at regular intervals of about
once per week. According to ASTM C666 (rapid freezing and thawing in water),
completion was defined at 300 cycles or when the average of percentage mass loss
exceeded 25% (whichever came first). Batis et al. (1996) reported that the CKD 10
concrete specimens had similar mass loss behaviour compared to the reference concrete
specimens at all three w/b ratios. The 6% CKD 9 concrete specimens had significantly
less resistance to rapid freezing and thawing compared to the reference concrete
specimens at all three w/b ratios.
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Wang and Ramakrishnan (1990) conducted studies on the freezing and thawing
performance of concrete made with a binary blend consisting of 5% CKD (CKD 12) and
95% TIII cement (PC 12). The concrete mixes were tested at w/b ratios of 0.45, 0.52, and
0.55. Freezing and thawing performance was evaluated using two sets of two specimens
for each type of mix. One set was exposed to the conditions specified in ASTM C666
while the other was used as a reference. In addition to monitoring changes in fundamental
transverse frequency to calculate durability factors, changes in length and mass were also
recorded. Wang and Ramakrishnan (1990) concluded that the concrete specimens with
CKD did not show inferior resistance to rapid freezing and thawing in up to 120 cycles
(84 days), but experienced a little more mass loss thereafter compared to the plain cement
concrete specimens.
Ramakrishnan and Balaguru (1987) conducted an experimental investigation on the
freezing and thawing durability of concretes in which 5% of the cement was replaced
with CKD 11. Three types of cement were assessed: Type I (PC 15), Type II (PC 13), and
TIII (PC 14). Six sets of concrete with cement contents of 386 kg/m3 and 332 kg/m3 were
tested. The w/b ratio was 0.45 for the higher cement content and 0.52 for the lower
cement content. The air content ranged from 3.1 – 8.4%. The freezing and thawing tests
were conducted according to ASTM C666, using 100 x 100 x 375 mm prisms. Mass loss,
fundamental resonant transverse, frequency, and pulse velocity were measured at
approximate intervals of 30 cycles. The freezing and thawing tests were stopped at 300
cycles. Ramakrishnan and Balaguru (1987) concluded that under freezing and thawing
conditions, kiln dust (5% by mass) incorporated behavior is essentially similar to that of
plain PC concretes.
A summary of the studies conducted on the freezing and thawing effects of CKD-PC
blends compared to each of the respective reference plain cement is shown in Table 2.28.
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Table 2.28 Freezing and thawing cycles: from CKD-PC literature review
Author(s)
Blend Type w/b % CKD Replacement
General Effect on Freezing and
Thawing Deterioration
Author Suggested Mechanism(s)
Batis et. al (1996)
CKD 9 / PC 10 CKD 10/ PC 10
C C
K K
0,6 0,6
↑ N.C.
Wang and Ramakrishnan (1990)
CKD 12/PC 12 C K 0,5 <120 cycles N.C. >120 cycles ↑
Ramakrishnan and Balaguru (1987)
CKD 12/PC 13 CKD 12/PC 14 CKD 12/PC 15
C C C
K K K
0,5 0,5 0,5
N.C. N.C. N.C.
P = Paste; M = Mortar; C = Concrete. V = varied w/b ratio to maintain consistent workability K = constant w/b ratio, but more than one w/b ratio was tested.
2.5.8.5 External Sulfate Resistance
Bhatty (1986) used a TI cement (PC 16) with three different CKDs (CKD 13, CKD 14,
and CKD 15) in mortars to investigate their effect on sulfate resistance (ASTM C1012).
The amount of CKD in each blend was fixed at 10% by mass of PC, with a w/b ratio of
0.45. Bhatty (1986) reported that the blends containing cement and CKD resulted in
expansions that were lower than cement alone. The author did not provide an explanation
for the improved sulfate resistance of the CKD blend. Improved sulfate resistance,
however, is often a result of lower permeability.
A summary of the study conducted on the external sulfate resistance effects of CKD-PC
blends compared to each of the respective reference plain cement is shown in Table 2.29.
Table 2.29 Sulfate resistance: from CKD-PC literature review
Author(s)
Blend Type w/b % Replacement Level
General Effect on External
Sulfate Resistance
Author Suggested Mechanism(s)
Bhatty (1986)
CKD 13/PC 16 CKD 14/PC 16 CKD 15/PC 16
M M M
0.45 0.45 0.45
0,10 0,10 0,10
↑ ↑ ↑
P = Paste; M = Mortar; C = Concrete.
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2.5.8.6 Durability Summary
Although there are relatively few studies on CKD-PC blend durability, researchers have
stated the need to consider potential issues due to the composition of CKD (Wang et al.,
2002; Dyer et al., 1999). Since CKD is typically high in sulfur, alkalis, and chlorides,
there is the potential for external sulfate expansion, AAR, and steel corrosion. The impact
of using CKDs as a substitute of PC on microstructure and air content could affect
permeability and resistance to freezing and thawing cycles. One study on AAR reported a
potential increase for AAR using CKDs, while another study reported no impact.
Differences in expansion of CKD blends with similar alkali contents indicates that factors
other than alkali content – such as the type of alkali compound and/or the CKD-PC
chemical composition – can play a role in AAR. Steel corrosion increased as the amount
of CKD increased. A major contributor to steel corrosion can be the high chloride content
of CKD. The high alkali content of CKD, however, can help in maintaining the high
passivation film layer that protects steel. One study reported that permeability was
reduced with CKD, likely due to the presence of fine particles. Lower permeability
indicates higher durability. Three studies using blends with 5% and 6% CKD
replacement of PC reported no impact in four blends and increased mass loss in two
blends when exposed to freezing and thawing cycles. One study showed that CKD blends
improve resistance to external sulfate attack. Possible explanations for the freezing and
thawing and sulfate resistance effects of CKD blends were not provided.
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3.0 MATERIALS AND EXPERIMENTAL DETAILS
This thesis consists of several experiments that were designed to provide data within the
context of two main objectives:
1. Investigate the characterization of CKDs using chemical, physical, mineralogical,
and dissolution analytical techniques
2. Establish an improved understanding of the effects of CKDs as partial substitution
for PC on:
a. heat of hydration
b. normal consistency
c. initial set time
d. compressive strength
e. expansion in limewater
f. soundness
g. ASR.
3.1 Materials
The materials used in this study were seven different CKDs (identified as A, B, C, D, D*,
E, and F) having a wide range of chemical/mineralogical and physical properties based
on different raw material sources and technologies, two filler materials (limestone
powder and ground silica), and two PCs of high and low alkali content (Cements TI and
TII, respectively). Each PC consists of only clinker and gypsum (pure PC). Limestone
powder (LS) and ground silica (inert) (SLX) were selected for comparison to the CKDs,
based on similar Blaine fineness.
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All CKDs were fresh, as opposed to coming from a stockpile or landfill. The CKDs in
this study were selected to provide a representation of available CKDs in North America
from the three major types of cement manufacturing processes: wet, long-dry, and
preheater/precalciner, as shown in Table 3.1. The CKDs are from different cement plants
except CKDs D and D*, which are from the same plant. Only one sample from each
cement plant was planned but due to the uncharacteristically low Blaine fineness value of
the original sample (CKD D*), a second sample was collected (CKD D).
Table 3.1 CKD kiln process description
CKDs Kiln Process Dust Collection System
A Wet Electrostatic Precipitator
B Wet Bag-house
C Long-dry Electrostatic Precipitator
D, D* Long-dry Bag-house
E Precalciner (By-pass) Electrostatic Precipitator
F Precalciner (By-pass) Electrostatic Precipitator
Due to the length of the study, all materials were stored in plastic bags that were placed in
airtight plastic pails between uses. LOI was performed on all materials periodically to
ensure that (i) no moisture had been absorbed and (ii) they had not carbonated. LOI
results indicated that the materials did not change over time.
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3.2 Testing of Raw Materials
3.2.1 Chemical Properties
The chemical compositions of the PCs were determined in accordance with ASTM C114.
X-ray fluorescence (XRF) was used to determine the major elements likely to be present
in PC, with the exception of moisture and carbon dioxide (CO2). The samples were de-
carbonized prior to XRF analysis using LOI. The LOI required igniting the dried sample
to a constant mass in a muffle furnace at 950 ± 50˚C in an uncovered porcelain crucible.
After the PCs had reached constant mass (in approximately 1 hour), samples were
prepared as fused beads using lithium borate. Fused beads were prepared by dissolving
the specimen in lithium borate at a high temperature (>1000˚C). Then the fused bead
samples were placed in the XRF spectrometer to determine the major elements. The
alkali, sulfate, and chloride contents for PCs from the XRF analysis were validated using
flame photometry, induction heating (LECO SC-432 Sulfur Analyzer), and
potentiometric titration. Water soluble alkali content was determined according to ASTM
C114. One gram of material is put in contact with water for 10 minutes and, after
filtration, the amount of water soluble alkalis contained in the aliquot was determined by
flame photometry. Some testing procedures developed for PC were modified to
accurately determine the chemical composition of the CKDs; these are described in
Section 4.1.1.
3.2.2 Mineralogical Properties
The free lime (free calcium oxide) test that is designed for PC (ASTM C114) using hot
benzoic acid titration was used for each PC and CKD. Mineralogical characterization of
all materials included X-ray diffraction (XRD) and thermal analyses. XRD was
performed with a Rigaku D/MAX 2000 diffractometer on pressed powder samples,
except CKD D, which was analyzed using PANalytical’s X’Pert PRO. Scanning was
performed in the range of 5º ≤ 2θ ≤ 65º with a scan rate of 0.02º 2θ per second. Powder
samples were analyzed using standard monochromatic CuKά radiation generated at
20mA and 40 kV. PC gypsum phases were obtained by differential scanning conduction
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calorimetry (DSC) using the Mettler TA3000 System. CKD samples were analyzed by
thermo gravimetric analysis (TGA) in a nitrogen environment using a Netzsch STA 730
thermal analysis apparatus at a heating rate of 10˚C/minute.
3.2.3 Physical Properties
The relative density of each material was obtained by air-comparison pycnometer. The
relative density of the material is a required input in the calculation to determine the
Blaine fineness. The Blaine air permeability test (ASTM C204) and the percentage of
material finer than 45 µm (No. 325) sieve (ASTM C430) were used to determine the
fineness of all materials in this research program. The Blaine fineness test is the most
widely used method to assess the fineness of PC. The Blaine fineness test indirectly
measures the surface area of the cement particles per unit mass. Particle size distribution
(PSD) of all materials was also determined using the Malvern laser diffraction particle
sizer, 2600 Series. Although there is presently no standard specification for determining
the particle size distribution of PC, the cement industry commonly uses this test method
to determine fineness of materials. The usual procedures for measuring PC fineness were
slightly modified to accurately measure the fineness of the CKDs and fillers; these are
discussed in Section 4.1.3.
3.2.4 Dilute Stirred Suspensions
Dilute stirred suspensions were performed on each PC and CKD. A sample of each
material was mixed with water in a glass beaker with a water to solid ratio of 10. Each
mixture was stirred vigorously for 10 minutes by hand with a glass rod and the
temperature of the solution was maintained at approximately 23ºC. The solid material
was then separated using a vacuum filter. The liquid solution was placed in a sample tube
for analysis. Hyroxyl ion concentration was measured immediately for each sample. Then
the solution filtrate was brought to a pH of less than two using nitric acid. The purpose of
adjusting the sample pH to less than two was to minimize metal cation precipitation and
adsorption onto the sample container wall. It is known that nitric acid can also cause
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certain elements from glass ampoules to become soluble. Therefore, appropriate plastic
ampoules were used to collect the samples. The balance of the cation and sulfide ionic
concentrations of each solution was determined by using Inductively Coupled Plasma
Atomic Emission Spectrometry (ICP AES) directly; the model used was the Perkin Elmer
Model Optima 3000DV ICP AEOS. The chloride ion concentration was approximated
using the U.S. Geological Survey public domain PHREEQC geochemical software
package.
3.3 CKD-PC Blends
For paste and mortar tests, the amount of CKD (CKD A, B, C, D, E, or F), limestone
powder, or silica flour in each blend was either 10% or 20% replacement of PC, by mass.
This resulted in 30 binder blends: 2 PC binder blends, 24 CKD-PC binder blends, and 4
PC-filler binder blends. All materials were sieved on a No. 20 sieve and weighed
accurately. Each blend was then homogenized by hand with a large spoon in a steel bowl
prior to the addition of water and/or fine aggregate (mortar sand). The paste and mortar
tests used in this study are described in Sections 3.3.1 to 3.3.7.
For concrete tests, the amount of CKD ranged between 7% and 13% replacement of PC,
by mass. CKD D was not available at the time of concrete casting, so the low Blaine
fineness CKD D* was used. The concrete CKD-PC blend tests are described in further
detail in Section 3.3.8.
3.3.1 Heat of Hydration
PC hydration leads to the evolution of heat and, consequently, isothermal conduction
calorimetry is commonly used to assess hydration kinetics of different paste blends. In
this study, the TAM Air isothermal conduction calorimeter was used to determine the
effects of the CKDs and fillers on the early hydration characteristics of the blends in
accordance with ASTM C1679. Eight samples can be analyzed at a time and an air
thermostat is used to maintain the isothermal temperature, which can be set between 15
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and 60°C. The TAM Air utilizes heat conduction to transfer heat away from the sample
to a heat sink to keep the sample temperature essentially constant. The flow of heat,
caused by the temperature gradient across the sensor, creates a voltage signal
proportional to the heat flow. The heat output is calibrated by measuring the output from
a known heat source under identical conditions to the hydrating material. To minimize
disturbances from outside the calorimeter, an inert reference sample is used. The inert
sample is placed on a parallel heat flow sensor. Any external disturbances will influence
both the sample and the inert sample identically and be nullified. The detection limit of
the TAM AIR is 2 µW and the precision is specified to be ±10 µW. The time constant is
approximately 100 seconds. The results can be presented as either differential plots
showing the rate of heat evolution as a function of time or integral plots showing the total
amount of heat liberated as a function of time.
All materials were stored in tightly sealed plastic bags inside containers at a constant
temperature of 23 ± 2°C to pre-condition them prior to testing. Paste specimens with 150
g of solids and a w/b of 0.4 were prepared to study the heat of hydration at 23°C.
Distilled water was added to the solids and mixed for 2 minutes in a steel bowl using a
kitchen hand-blender at low speed. After 2 minutes, approximately 8 g of paste sample
were extracted from the bowl using a 10 ml syringe and injected into a glass ampoule. All
paste samples were weighed by mass difference between the glass ampoule with the
sample and the empty glass ampoule. The sample was then sealed and placed in the
calorimeter, five minutes after the distilled water was initially added. A corresponding
reference sample containing inert silica sand was also placed into the calorimeter. The
amount of silica sand was determined by calculating the equivalent specific heat capacity
to 8 g of PC paste. Heat of hydration for each paste specimen was measured over seven
days and performed in duplicate. The rates of heat evolution (mW/g) were measured and
recorded approximately every 10 seconds using a computer data acquisition system.
Since mixing of the constituents was carried out prior to introducing the sample into the
calorimeter, the first five minutes of heat evolution were not measured.
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3.3.2 Normal Consistency
Normal consistency is a term that is used to describe the degree of plasticity of a freshly
mixed PC paste. The normal consistency (w/b ratio expressed as a percentage) was
determined for all binders in accordance with ASTM C187. For each binder blend, 650 g
of solid material were mixed with water to make a paste. The amount of water required to
bring the paste to a standard condition of wetness was regulated by the condition for
which the penetration of a standard needle (Vicat needle) into the paste is 10 ± 1 mm in
30 seconds. In order to gain appreciation for the accuracy of this test, ASTM C187
stipulates that the results of single-operator tests should not differ by more than 0.7%.
3.3.3 Initial Setting Time
The initial setting time is often used to evaluate if a paste is undergoing normal hydration
reactions. Initial setting time is defined as the time that elapses from the moment water is
added until the paste ceases to be fluid and plastic. Most PCs attain initial set within two
to four hours. For each binder blend, the paste that was mixed to determine normal
consistency was also used to determine initial set time. The time of initial setting of the
blended pastes was determined using a Vicat apparatus according to ASTM C191. The
time at which the needle penetrates 25 mm into the paste at room temperature was taken
to define the initial setting. ASTM C191 specifies that the penetration of the Vicate
needle in the paste should be checked 30 minutes after moulding and every 15 minutes
thereafter until a penetration of 25 mm or less is obtained. According to ASTM C191, the
single operator standard deviation has been found to be ±12 minutes within a range of 49
to 202 minutes initial setting time. To increase the accuracy of the initial set time
measurement, the test procedure was modified by increasing the frequency of the Vicat
penetrations to every five minutes as the paste approached initial set.
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3.3.4 Flow
Flow is used to describe the relative mobility (ability to flow) of mortar. The flow for
each binder blend was determined on a flow table as described in ASTM C230. Mortars
were mixed in accordance with ASTM C305 with one part of binder blend, 2.75 parts of
graded sand, and deionized water. Mortars were mixed for each binder blend to
determine (i) the flow at a fixed w/b ratio of 0.485 and (ii) the water demand to yield a
flow of 110 ± 5 according to ASTM C1437. ASTM C1437 states that the results of
properly conducted tests should differ by no more than 11% for single-operator testing.
3.3.5 Compressive Strength
Compressive strength is the most commonly used method to assess cement quality. The
compressive strength for each binder blend was determined according to ASTM C109
(CSA A456.2-C3) at 1, 3, 7, 28, and 90 days. 50 mm mortar cube specimens were
prepared by mixing one part of binder blend material, 2.75 parts of graded sand, and
deionized water addition (w/b ratio of 0.485). The specimens were cured in a humidity
chamber at 23±1 °C for 24 hours, then demoulded and immersed in lime saturated water
until tested. The compressive strength result is the average of three test specimens from a
single batch at the specified curing time. ASTM C109 states that when three cubes
represent a test age, the maximum permissible range between specimens from the same
mortar batch at the same test age is 8.7% of the average.
3.3.6 Expansion in Limewater
ASTM C1038 is a test method that is used to determine the expansion of mortar bars
made from PC in saturated limewater. The amount of expansion is typically related to the
amount of calcium sulfate in the PC. In this study, ASTM C1038 was used to assess the
expansion of all binder blends. Mortars were mixed in accordance with ASTM C305 with
one part of binder blend, 2.75 parts of graded sand, and deionized water. The amount of
water required to yield a flow of 110 ± 5 according to ASTM C1437 was used for each
binder blend. Four mortar bar specimens (25 x 25 x 285 mm) were prepared for each
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binder blend and the expansion was calculated as the mean of four mortar bars. The test
method specifies calculating the difference in length of specimens at 24 hours from the
time the binder blend was mixed with water and at 14 days. The length change of the
mortars made from different blends, however, was also measured up to one year for most
blends. An expansion limit of 0.020% in 14 days of limewater immersion is in use in
CSA A3001.
3.3.7 Autoclave Expansion
Soundness refers to the ability of a paste to retain its volume after it has set. Unsoundness
can arise from excessive amounts of hard burned free lime or free magnesia and has the
potential to cause delayed destructive expansion. In the autoclave expansion test (ASTM
C151), a cement paste specimen (25 x 25 x 285 mm) is placed in an autoclave for three
hours at 2 MPa and approximately 216°C. The difference between measurements of the
specimen taken before and after the autoclave treatment represents the expansion due to
unsoundness. The autoclave expansion test method was used to measure expansion due to
the combined effects of both magnesia and free lime for each binder blend. For each
binder blend paste, the same w/b ratio used to attain normal consistency and initial setting
time was used for the autoclave test. ASTM C151 states that the results of two properly
conducted tests by the same operator for expansion of similar batches should not differ
from each other by more than 0.07% expansion.
3.3.8 Alkali Silica Reactivity
The concrete prism test is typically used to evaluate the reactivity of aggregate with
respect to ASR and also to examine the impact of materials that may be introduced to
suppress the expansion due to ASR. The typical test period for evaluating the reactivity
of an aggregate is one year, and at least two years with SCM (CSA A23.2-14A and
ASTM C1293). For the proposed research study, this test method was modified to assess
the direct impact on ASR when using CKD as a partial replacement of PC. The main
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purpose of this study was to make relative comparison of the binary blends rather than
obtaining the absolute values.
The materials used for the ASR concrete durability study were six different CKDs (A, B,
C, D*, E and F) and two PCs of high and low alkali content (TI and TII). CKD D and the
fillers were unfortunately not available at the time of casting for the concrete prisms. Two
series of concrete prisms were cast to assess the effect of CKDs on ASR with Cements TI
and TII. The reactive aggregate susceptible to ASR that was used in this study is Sudbury
aggregate.
The w/b ratio for all mixes was in the range of 0.42 – 0.45 to maintain a constant slump.
The three equal reactive coarse aggregate fractions by mass were of 10, 15, and 20 mm
nominal maximum diameter, respectively. The specific gravity of the reactive coarse
aggregate was 2.71. The fine aggregate had a fineness modulus of 2.90 and a specific
gravity of 2.68. The freshly mixed concrete was tested for slump (ASTM C143), air
content (ASTM C231, pressure method), and unit mass (ASTM C138). Two concrete
cylinders measuring 100 x 200 mm were prepared from each batch. The cylinders were
stored moist at 38 ºC and tested for compressive strength at 28 days. Four concrete
specimens from each batch were prepared, measuring 75 x 75 x 300 mm. The expansion
of the concrete specimens was measured every three months for a period of 365 days.
For each concrete mixture investigated, the expansion (length change divided by the
gauge length) was calculated as the mean of four concrete prisms. Mass was also
measured for each concrete prism and the mass change was averaged for the four prisms.
ASR Test Series 1: The first set of concrete prisms was cast using 10% replacement of
Cement TI with CKD binders (CKD and/or PC). The total alkali content of the concrete
was increased to 1.25% Na2Oe of binder mass by adding sodium hydroxide (NaOH) to
the mixing water. Cement TI as the binder material alone was used in two control
mixtures (Cements TI CTL 1 and CTL 2). The total solid binder was 420 kg/m3 for each
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mix except for Cement TI CTL 2, which was 378 kg/m3. Cement TI CTL 2 contained the
same amount of PC as in the concrete blends with CKDs. Due to the reduction in solid
binder material, the Cement TI CTL 2 alkali level was increased to 1.38% Na2Oe of
binder mass to give the same total alkali loading as the other blends in Test Series 1.
ASR Test Series 2: The second set of concrete prisms was cast using Cement TII and
varying amounts of PC replacement with CKDs. A constant amount of NaOH was added
to each mix. The total alkali content of the concrete was increased to 1.25% (Na2Oe) of
cement mass by adjusting the amount of CKD replacement in each mix. The amount of
NaOH addition to each mix was selected to maintain the range of CKD replacement
levels generally close to 10%. The total solid binder for each mix was 420 kg/m3. Cement
TII as the binder material alone was used in two control mixtures (Cements TII CTL 1
and CTL 2). Cement TII CTL 2 alkali content was raised using NaOH to a level of 1.03%
Na2Oe of binder mass, rather than the 1.25% of alkali loading to give the same total alkali
loading contribution of NaOH as the other CKD blends in Test Series 2.
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4.0 RESULTS AND DISCUSSION
4.1 Material Characterization
The first objective of this thesis was to characterize the seven CKDs, two PCs, and two
filler materials. It was found that some of the analytical methods designed for PC do not
always provide accurate compositional analysis for CKDs. Therefore, the analytical
methods required for accurate analysis of CKDs were identified. The complete chemical
analysis and physical properties (relative density, Blaine fineness, and percentage of fine
material below 45 µm) of all materials were performed. In addition to the chemical
composition and standard fineness tests, quantitative mineralogical compositions, particle
size distributions, and dilute stirred suspension analyses were also performed.
4.1.1 Chemical Properties
The characteristics of materials used in cement are traditionally evaluated by an oxide
composition based on chemical analysis data. Chemical makeup of a CKD and PC can
provide an important indicator of how the CKD-PC blend will perform. It was found that
there are very few published works with complete chemical analysis of CKDs in the
research of CKD-PC blends. The incomplete CKD chemical composition data provided
in previous studies is likely due in part to the application of analytical procedures that are
specifically designed for PC, rather than CKDs.
The chemical compositions of the two PCs were determined in accordance with ASTM
C114 using X-ray fluorescence (XRF), as stated in Chapter 3. Prior to XRF analysis, loss
on ignition (LOI) was performed by igniting the 110˚C dried sample to a constant mass in
a muffle furnace at 950 ± 50˚C in an uncovered crucible for 1h. The LOI values obtained
result from either exposure to moisture or CO2 (since each of the two PCs only consists
of clinker and gypsum, there is no contribution of CO2 from carbonate additions).
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CKDs usually take between 12 to 24 hours to reach constant mass at 950 ± 50 ˚C. The
LOI for CKDs not only reflects prehydration and decarbonization, but also the presence
of volatiles (alkali, sulfate, and/or chloride). The ranges of volatilization at the melting
point of compounds found in CKDs are shown in Table 4.1. A large percentage of the
CKD volatiles will be released from the sample into the atmosphere during the LOI test
and during preparation of the fused beads since they are less stable in CKDs than in PC at
950 ± 50 ˚C. This presents two problems: (i) the LOI is not just CO2 and (ii) the XRF
quantification of alkali, sulfate, and/or chloride is underestimated. Therefore, direct
testing procedures developed for PC in ASTM C114 were used to accurately determine
the volatile composition of the CKDs (Babikan and Verville, 2007). The test methods
used to measure the volatiles of CKDs were: flame photometry for alkalis, induction
heating for sulfate, and potentiometric titration for chloride. The XRF chemical analysis
values were then corrected by accounting for the volatiles that were released during the
LOI test. The process that was used for chemical analysis of the CKDs is described in
Figure 4.1. The CKD chemical composition calculations are presented in Appendix A.
Table 4.1 Melting points and volatility of compounds in CKDs (Manias, 2004)
(Note: This table is the same as Table 2.3)
Volatile Compounds Melting Point, ˚C Range of volatility*, %
CaCl2 772 60 to 80
KCl 776 60 to 80
NaCl 801 50 to 60
Na2SO4 884 35 to 50
K2SO4 1069 40 to 60
CaSO4 1280 ---
*Range of volatility: % of compound that will volatilize at melting point
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Figure 4.1 Process flow chart for CKD chemical composition analysis
The free lime test for PCs is typically used to determine the free calcium oxide content.
This test, however, is also sensitive to calcium hydroxide. The free lime test gives the
total of free calcium oxide plus calcium hydroxide contents and does not differentiate
between the two. This is generally not an issue for PC free lime analysis since the
presence of calcium hydroxide is rare (except in PC that consists of weathered clinker).
CKDs, however, can be exposed to moisture during processing to reduce fugitive dust
and/or storage outside. Therefore, the results from the free lime test for CKDs should be
considered as representative of the combined free calcium oxide and calcium hydroxide
contents.
CKD Sample
CKD Sub-sample 1
CKD Sub-sample 2
CKD Sub-sample 3
CKD Sub-sample 4
LOI and XRF
Analysis
Calculate chemical composition by
accounting for volatiles
released during LOI test
Chloride Content: Potentiometric
Titration
Sulfate Content: Induction Furnace
Alkali Content:
Flame Photometry
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The chemical and standard physical properties (relative density, Blaine fineness, and fine
material below 45 µm) of all materials are shown in Table 4.2. Cement TI met the
specifications for normal PC and is characterized by a relatively high sulfate (4.35%),
high total alkali content (0.97%), and high C3A content (11.3%). Cement TII met the
specification for a moderate sulfate resistant cement and is characterized by its low C3A
(6.1%) and low total alkali (0.57%) contents. The data in Table 4.2 shows the LS and
SLX to consist of 95.52% calcite based on 53.49% / 56.00% CaO (by LOI, 42.29% /
44.00% = 96.11%) and 98.15% quartz, respectively.
Comparison of the current CKDs to those from previous research studies as summarized
by Sreekrishnavilasm et al. (2006) (Table 2.5) shows that all CKDs were within the
maximum-minimum range of the compositions, except for the free lime values for CKDs
E and F. CKDs A, B, and C appear to be particularly similar to those in the previously
published literature. CKDs A and C were within the standard deviations for each
parameter. CKD B had concentrations of calcium oxide, silicon dioxide, and aluminum
oxide slightly outside the respective range for standard deviation. CKDs D*, D, E, and F,
however, appear to be slightly different from the published dataset. CKDs D*, D, and E
each had values for sulfate above the range for standard deviation. CKDs D*, E, and F
had higher free limes than the upper limit of the standard deviation. CKDs E and F also
had calcium oxide and magnesium oxide contents above the respective ranges for
standard deviation. The chloride levels of the CKDs within this study appear to be lower
than the full range of chloride levels found in CKDs from previous studies.
As a note of interest, the CKD oxide composition statistical analysis of intermittent daily
samples collected over a 3 year period from the same kiln source as CKD C is presented
in Table 2.9. Although more variable than PC, the standard deviation results indicate that
the CKD from this kiln source is quite consistent.
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Table 4.2 Chemical and select physical components of PC, CKD, and filler materials
Total Sum (High)d 99.92 99.88 104.95 102.15 100.84 101.16 100.83 105.07 101.27 100.15 99.06
Total Sum (Real)e 99.92 99.88 99.08 99.79 99.73 100.31 100.02 99.74 99.34 100.15 99.06
Free Limef 0.70 1.53 4.50 4.04 5.70 18.20 10.59 29.20 38.20 0.00 0.00 a Equivalent Alkali (Na2O + 0.658 K2O) b Equivalent Water Sol. Alkali (Water Sol. Na2O + 0.658 Water Sol. K2O) c Loss on ignition determined at 950 ± 50 ºC d XRF sum of total oxides e Sum of total oxides calculated by removing the volatiles that are included in the LOI (Na2O, K2O, Cl-) f Free lime: combined CaO & Ca(OH)2 content
Each CKD has its own characteristics, but there can be some generalization of these
particular CKDs based upon the pyroprocess, especially in free lime and chloride
contents. As expected, the wet and long-dry kilns had free lime contents that are lower
than the precalciner kilns. CKDs D* and D have higher free limes than typical long-dry
kiln CKDs due to unique equipment design in the kiln, but they are still lower than the
precalciner CKDs E and F free limes. The long-dry kiln CKDs have low chloride and
high sulfate contents in comparison to the wet and precalciner CKDs.
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The CKDs were generally higher in total alkali, sulfate, chloride, LOI, and free lime than
Cements TI and TII, as shown in Table 4.1. Water soluble alkalis are not normally
reported for PCs, although the test method is described in ASTM C114. The CKDs
contained higher levels of water soluble alkalis than the Cements TI and TII. It is
interesting to note that although the quantity of soluble alkalis is higher in CKDs, the
ratio of water soluble alkalis to total alkalis is higher in Cements TI and TII.
Statements/Observations:
4.i The ASTM C114 techniques specified for PC chemical analysis are not
necessarily sufficient and/or appropriate for CKD chemical analysis. The mass
of CKD at 950 ± 50 ˚C is not stable until 12 – 24 hours. Therefore, the 1-hour
PC standard LOI test duration is not sufficient to determine LOI for CKDs.
Further, LOI and fused bead preparation of CKDs can cause the volatile
compounds to be released into the atmosphere prior to chemical composition
analysis. Babikan and Verville (2007) recommend using the following tests in
ASTM C114 to determine the chemical composition of CKD volatile
elements:
i. Alkalis: flame photometry
ii. Sulfates: induction furnace
iii. Chloride: potentiometric titration
4.ii Although PC typically only contains free calcium oxide, the PC free lime test
is representative of both free calcium oxide and calcium hydroxide. CKDs are
more likely to contain calcium hydroxide than PC due to exposure to moisture
during handling and storage.
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4.1.2 Mineralogical Properties
CKD mineralogical analysis (determination of the relative abundance of the different
phases) is an essential complement of the chemical analysis. The effects of CKD
elements in a CKD-PC blend may vary depending on the form in which they actually
exist. The characteristics of CKD are traditionally evaluated based on chemical analysis
data. Such data does not, however, indicate the ways in which the different elements
actually exist within the CKD and how they might be expected to react during hydration.
Soluble alkalis, for example, may occur as separate crystalline phases in the form of
alkali chlorides or alkali sulfates. The reactivity of elements may, therefore, be expected
to vary, depending on the form in which they actually exist.
The traditional methods (Bogue equations, XRD Rietveld analysis, and thermal analysis)
were used to assess the PC mineralogical compositions. Although quantifying the
mineralogical composition of PC has been thoroughly explored, the data to quantify the
mineralogical phases of CKDs is relatively limited. Mineralogical analysis of CKDs has
not been thoroughly evaluated due to a lack of quantitative analytical techniques. A
method for mineralogical phase quantification of CKDs using XRD diffraction scans,
Rietveld refinement, and physical tests (thermal analysis and titration) is introduced in
this section.
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Rietveld analyses of Cements TI and TII were performed using the X-ray diffraction
scans and control files developed “in-house” at Lafarge North America. The
mineralogical compositions of the PCs were determined by Rietveld quantitative X-ray
diffraction analysis, shown in Table 4.3(a). Alite (impure C3S) typically contains 3 – 4%
of substituent oxides, the most significant of which are iron, magnesium, and aluminum.
Belite (impure C2S) may contain 4 – 6% of substituent oxides of which aluminum and
iron are most common (Taylor, 1997). The potential proportions of C3S, C2S, C3A, and
C4AF compounds in each PC, calculated based on the Bogue equations in ASTM C150,
are shown in Table 4.3b. Taylor (1997) has noted that Bogue calculations can differ
considerably from the true phase compositions, especially by underestimation of alite and
overestimation of belite because the actual composition of these phases differs
considerably from those of the pure form.
Table 4.3 Cements TI and TII mineralogical composition (mass %) (a) XRD Rietveld Analysis (b) Bogue Compound Calculation
Phase TI TII Phase TI TII
Alite, C3S 68.6 66.5 C3S 51.9 60.7
Belite, C2S 10.3 15.2 C2S 15.8 12.6
Aluminate, C3A 8.7 3.0 C3A 11.3 6.1
Ferrite, C4AF 7.5 8.9 C4AF 7.5 9.1
Lime, CaO 0.0 0.2
Periclase, MgO 1.4 2.5 Gypsum, CaSO4·2H2O 1.7 1.0
Hemihydrate, CaSO4·0.5H2O 0.5 0.6
Anhydrite, CaSO4 0.2 0.9
Calcite, CaCO3 0.7 0.8
Portlandite, Ca(OH)2 0.1 0.4
Quartz, SiO2 0.3 0.2
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Cement TI has considerably more gypsum (readily soluble calcium sulfate) than Cement
TII. PC with high aluminate contents typically require a sufficient amount of added
calcium sulfate as a set controlling agent, which increases the sulfate content of the PC. It
follows that cements low in aluminate require less added calcium sulfate and would tend
to have lower sulfate contents.
Thermogravimetric analysis (TGA) is ideally suited to quantify the degree of calcination
and amount of calcium hydroxide (portlandite) present in CKDs. Samples were tested in
a temperature range from 30˚C to 950˚C. Portlandite decomposed between 400 to 530˚C
and calcium carbonate was detected between 700 to 850˚C. The TGA results for Cements
TI and TII and the CKDs are presented in Appendix B. An approximate determination of
portlandite (Ca(OH)2) was established using mass balance calculations and the TGA
results. The portlandite was then subtracted from the total free lime (calcium oxide and
calcium hydroxide) in Table 4.2 (based on equivalent calcium oxide) to determine the
free calcium oxide (CaO) portion. The mineralogical composition of calcite, portlandite,
and free calcium oxide is shown in Table 4.4.
Table 4.4 CKD mineralogical compositions using direct test methods (mass %)
Components Cement Kiln Dusts (CKDs) A B C D* D E F
vi. CKDs influence the strength development of CKD-PC blends and tend
to have low early strengths and higher late age strengths. The increased
sulfate contents (beyond the PC optimum sulfate content) of the CKD-
PC blends reduced early age strengths. In the absence of high CKD
sulfate content, increased chloride content due to CKDs increased early
age strengths. For Cement TI (normal C3A), later age strengths were
adversely affected due to a lower percentage of particles passing the 45
µm sieve. For Cement TII (low C3A), the calcium carbonate fraction of
CKD performed as a diluent and resulted in lower later-age strengths.
vii. CKD-PC blends have higher expanions in limewater than PC alone.
Increased expansions in limewater of CKD-PC blends are linearly
related to increased concentrations of sulfate in the binder, likely due to
the formation of AFt in the hardened paste. It is believed that an
optimized sulfate content for a CKD-PC blend would mitigate these
expansions.
251
viii. CKD-PC blends have higher autoclave expansions than PC alone.
Increased autoclave expansions are related to high amounts of hard burnt
free lime content as opposed to total free lime content. It appears there
are also other contributing factors to autoclave expansion, such as the
presence of coarser particles in CKDs.
4. This study provides a contribution to the limited data that exists for the impact of
CKD-PC blends on ASR. It appears CKD-PC blends will result in higher ASR
expansion and that mitigative measures may have to be increased from those
currently recommended in CSA A23.2-27A.
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6.0 CONCLUSIONS
Within the range of materials and CKD replacement levels investigated in this study, the
following conclusions are made.
1. CKD compositions vary with kiln process and the raw materials used. Therefore, the
impact of CKD as a partial replacement of PC may not be consistent. Further, a
particular CKD may impact CKD-PC blends differently due to varying compositions
in PC.
2. Thermal and compositional anaylsis methods used for PC must be modified to use on
CKDs by correcting for the volatile compounds that may be released during the LOI
test and fused bead preparation.
3. CKDs may contain significant amounts of amorphous material (>30%) and clinker
compounds (>20%) and small amounts of slag and/or fly ash (<5%) (if used as raw
materials in clinker production) and calcium langbeinite (<5%). Although these
materials/compounds do not necessarily govern the impact of CKD in a CKD-PC
blend, it is important to recognize they can have an influence on hydration and on the
compounds that are formed.
4. CKDs from preheater/precalciners have different effects on workability and heat
evolution than CKDs from the wet and long-dry kilns. The blends with the two CKDs
from preheater/precalciner plants had higher paste water demand, lower mortar flows,
and higher heat generation during initial hydrolysis in comparison to all other blends
and control cements. This is due to the high amounts of reactive free lime (>20%) in
CKDs from preheater/precalciner processes.
253
5. The effect of CKD as a partial replacement of PC appears to be governed by the
sulfate content of the CKD-PC blend (however, the form of the CKD sulfate is not
significant). According to the analysis of the ASTM C1038 expansion in limewater
test results in this study, the CKD-PC sulfate content should be less than ~0.40%
above the optimum sulfate content of the PC.
6. CKD in CKD-PC blends behaved similarly to the addition of gypsum to PC.
Therefore, CKD-PC blends could be optimized for sulfate content by using CKD as a
partial substitute of the gypsum during the grinding process to control the early
hydration of C3A. The wet and long-dry kiln CKDs contain significant amounts of
calcium carbonate (>20%) which could also be used as partial replacement of
limestone filler in PC. The impact of additional CKD components would need to be
considered.
7. With the knowledge gained in this thesis and other research studies, there may be
efforts directed towards modifying North American industry standards to allow for
appropriate utilization of CKDs as partial replacement of PC, between 5 and 10% by
mass. These changes would likely require less emphasis on the use of compositional
specifications and greater importance on the use of performance standards such as
ASTM C1157.
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7.0 RECOMMENDATIONS FOR FUTURE WORK
1. The current study provides an understanding of the effect of free calcium and
sulfate ions from CKDs on C3S and C3A hydration in CKD-PC blends. Many of
the adverse effects of CKD-PC blends are related to excessive sulfate contents. It
would be useful to assess performance of the CKD-PC blends at optimum sulfate
content (as a partial substitute of gypsum).
2. The excessive contribution of free calcium and sulfate ions from CKDs appears to
dominate the behaviour of CKD-PC blends. Since gypsum (calcium sulfate) is
known to have a significant impact on drying shrinkage, this is another volume
stability parameter that should be investigated.
3. The two CKDs from preheater/precalciner plants performed significantly
differently in comparison to the CKDs from the wet and long-dry kilns with
respect to influence on water demand and flow. It would be beneficial to conduct
future studies with preheater/precalciner CKDs separate from wet and long-dry
kiln CKDs, particularly at PC replacement levels greater than 10%.
4. The current study utilized dry blending to mix the CKD-PC blends. Intergrinding
the CKD-PC blends, however, may produce different results. For example, it is
important to highlight the potential impact of highly reactive free lime to cause
gypsum false set if CKD from preheater/precalciners is interground with PC, as
opposed to being blended. Free lime, if too high and/or reactive, enhances
gypsum dehydration by its considerable hygroscopity (which allows it to extract
water from gypsum molecules during milling when they are in a state of
perturbation from the heat generated by frictional forces and liable to be subjected
to some decomposition) and also has the effect of delaying rehydration of
hemihydrate (Bensted, 1983b). This could enhance the likelihood of a plaster
255
(gypsum) false set. Therefore, the differences between intergrinding and blending
CKD-PC blends should be investigated.
5. The stirred suspension dissolution analyses of CKDs and PCs at w/b ratio of 10:1
were very useful to gain an understanding of rapid ion dissolution differences
between CKDs and PC during early age hydration. It would be interesting to
conduct further investigations of the actual CKD-PC blend pore solutions with
more practical w/b ratios, such as 0.4 to 0.7 at various ages. It is recommended
that the pore solution extractions be perfomed at very frequent periods during the
early stages of hydration. Geochemical software programming (i.e., PHREEQC)
could also be used to model and predict the hydration products at each stage.
6. The current study provides a hypothesis for the microstructural development of
CKD-PC blends during hydration based upon the effects and relationships among
the binder compositions and their performance in various physical tests. Further
work is needed to investigate the formation of hydration products as well as
morphology changes to C-S-H at various hydration ages.
7. The role of C3A is very important in CKD-PC blends. It would be interesting to
conduct studies on the reactions of C3A in the concomitant presence of calcium
sulfate, calcium chloride, and calcium carbonate. Each of these compounds is
known to react with C3A individually, but how they react together, as in CKDs, is
not yet clearly defined.
8. The hydration, mechanical properties, and durability effects of CKD-PC blends
with SCMs and/or chemical admixtures were not included in this study. This
needs to be investigated further.
256
9. The current study shows that CKDs contribute to deleterious ASR expansion
based upon the concrete prism tests. Measures to mitigate ASR expansion of
CKD-PC blends should be investigated, such as the addition of SCMs.
10. There are other durability concerns of CKD-PC blends, besides ASR. Elevated
concentrations of chlorides contribute to steel corrosion in concrete. Excessive
amounts of sulfate can contribute to internal sulfate attack. Higher alkali contents
can impact freezing and thawing resistance. Permeability may also be increased
due to the dilution of PC with CKDs. These durability concerns need to be
assessed.
257
8.0 REFERENCES
AASHTO M 85. Specification for Portland Cement. American Association of State and Highway Transportation Officials, Washington, DC. ACI 318. 2005. Building Code Requirements for Structural Concrete. American Concrete Institute, Farmington Hills, MI. Adaska, W. S., Tresouthick, S. W., and West, P. B. 1998. “Solidification and Stabilization of Waste Using Portland Cement”. Portland Cement Association, Research and Development EB071, Skokie, IL. Al-Harthy, A.S., Taha, R., Al-Maamary, F. 2003. “Effect of Cement Kiln Dust (CKD) on Mortar and Concrete Mixtures”. Construction and Building Materials, Vol. 17, No. 5, pp. 353-360. ASTM C39. 1999. Standard Test Method for Compressive Strength of Cylindrical
Concrete Specimens. American Society for Testing and Materials, Philadelphia, PA. ASTM C109. 1999. Standard Test Method for Compressive Strength of Hydraulic
Cement Mortars. American Society for Testing and Materials, Philadelphia, PA. ASTM C114. 2000. Standard Test Method for Chemical Analysis of Hydraulic Cement. American Society for Testing and Materials, Philadelphia, PA. ASTM C138. 1992. Standard Test Method for Unit Weight, Yield, and Air Content
(Gravimetric) of Concrete. American Society for Testing and Materials, Philadelphia, PA.
ASTM C143. 1998. Standard Test Method for Slump of Hydraulic-Cement Concrete. American Society for Testing and Materials, Philadelphia, PA.
ASTM C150. 2000. Standard Specification for Portland Cement. American Society for Testing and Materials, Philadelphia, PA. ASTM C151. 2000. Standard Test Method for Autoclave Expansion of Portland Cement. American Society for Testing and Materials, Philadelphia, PA. ASTM C157. 1999. Standard Test Method for Length Change of Hardened Hydraulic-
Cement Mortar and Concrete. American Society for Testing and Materials, Philadelphia, PA.
258
ASTM C186. 1998. Standard Test Method for Heat of Hydration of Hydraulic Cement. American Society for Testing and Materials, Philadelphia, PA. ASTM C187. 1998. Standard Test Method for Normal Consistency of Hydraulic Cement. American Society for Testing and Materials, Philadelphia, PA. ASTM C191. 1999. Standard Test Method for Time of Setting of Hydraulic Cement by
Vicat Needle. American Society for Testing and Materials, Philadelphia, PA. ASTM C204. 2000. Standard Test Method for Fineness of Hydraulic Cement by Air-
Permeability Apparatus. American Society for Testing and Materials, Philadelphia, PA. ASTM C227. 1997. Standard Test Method for Potential Alkali Reactivity of Cement-
Aggregate Combinations (Mortar-Bar Method). American Society for Testing and Materials, Philadelphia, PA.
ASTM C230. 1998. Standard Specification for Flow Table for Use in Tests of Hydraulic
Cement. American Society for Testing and Materials, Philadelphia, PA. ASTM C231. 1997. Standard Test Method for Air Content of Freshly Mixed Concrete by
the Pressure Method. American Society for Testing and Materials, Philadelphia, PA.
ASTM C430. 1996. Standard Test Method for Fineness of Hydraulic Cement by the 45-
µm (No. 325) Sieve. American Society for Testing and Materials, Philadelphia, PA. ASTM C451. 1999. Standard Test Method for Early Stiffening of Hydraulic Cement
(Paste Method). American Society for Testing and Materials, Philadelphia, PA. ASTM C465. 1999. Standard Specification for Processing Additions for Use in the
Manufacture of Hydraulic Cements. American Society for Testing and Materials, Philadelphia, PA. ASTM C666. 1997. Standard Test Method for Resistance of Concrete to Rapid Freezing
and Thawing. American Society for Testing and Materials, Philadelphia, PA. ASTM C876. 1991. Standard Test Method for Half-Cell Potentials of Uncoated
Reinforcing Steel in Concrete. American Society for Testing and Materials, Philadelphia, PA. ASTM C1012. 1995. Standard Test Method for Length Change of Hydraulic-Cement
Mortars Exposed to a Sulfate Solution. American Society for Testing and Materials, Philadelphia, PA.
259
ASTM C1038. 1995. Standard Test Method for Expansion of Hydraulic Cement Mortar
Bars Stored in Water. American Society for Testing and Materials, Philadelphia, PA. ASTM C1293. 2005. Standard Test Method for Determination of Length Change of
Concrete Due to Alkali-Silica Reaction. American Society for Testing and Materials, Philadelphia, PA. ASTM C1437. 2001. Standard Test Method for Flow of Hydraulic Cement Mortar. American Society for Testing and Materials, Philadelphia, PA. ASTM C1679. 2008. Standard Practice for Measuring Hydration Kinetics of Hydraulic
Cementitious Mixtures Using Isothermal Calorimetry1Test Method for Flow of Hydraulic
Cement Mortar. American Society for Testing and Materials, Philadelphia, PA. ASTM D5050. 1996. Standard Guide for Commercial Use of Lime Kiln Dusts and
Portland Cement Kiln Dusts. American Society for Testing and Materials, Philadelphia, PA. Babikan S.H. and Verville C. 2007. Internal Lafarge Testing Procedures. Lafarge Canada Inc., Montreal, Quebec. Barker, A.P. and Matthews J.D. 1989. “Heat release characteristics of limestone filled cements”. Performance of Limestone Filled Cements, Proc. Building Research Establishment Seminar, Garston, England, pp. 5.1-5.29. Batis, G., Katsiamboulas, A., Meletiou, C.A., and Chaniotakis, E. 1996. “Durability of Reinforced Concrete Made with Composite Cement Containing Cement Kiln Dust”. Concrete for Environment Enhancement and Protection: Proceedings of the
International Conference, Concrete in the Service of Mankind, R.K. Dhir and T.D. Dyer eds., University of Dundee, Dundee, United Kingdom, pp. 67-72. Bensted, J. 1980. “Some hydration investigations involving portland cement – Effect of calcium carbonate substitution of gypsum”. World Cement Technology, Vol. 11, No. 8, pp. 395-406. Bensted, J. 1983a. “Further hydration investigations involving portland cement and the substitution of limestone for gypsum”. World Cement Technology, Vol. 14, pp. 383-392. Bensted, J. 1983b, “Hydration of Portland Cement”. Advances in Cement Technology, Ghosh, S.N. (editor), Pergomon Press Ltd., Oxford, pp. 307-347. Bensted, J. 1987. “Some applications of conduction conduction calorimetry to cement hydration”. Advances in Cement Research, Vol. 1, No. 1, pp. 35-44.
260
Bentur, A. 1976. “Effect of Gypsum on the Hydration and Strength of C3S Pastes”. Journal of the American Ceramic Society, Vol. 59, No. 5-6, pp. 210-213. Bentz, D. P., Garboczi, E. J., Haecker, C. J., and Jensen, O.M. 1999. “Effects of cement particle size distribution on performance properties of Portland cement-based materials”. Cement and Concrete Research, Vol. 29, pp. 1663-1671. Bhattacharja, S. 1997. “Optimum Sulfate in Blended Cements”. Portland Cement
Association, Research and Development Serial No. 2057, Skokie, IL. Bhatty, M.S.Y. 1984. “Use of Cement Kiln Dust in Blended Cements”, World Cement, Vol. 15, No. 4, pp. 126-128, 131-134. Bhatty, M.S.Y. 1985a. “Kiln Dust Cement Blends Evaluated”. Rock Products, Vol. 88, No. 10, pp. 47-52, 65. Bhatty, M.S.Y. 1985b. “Use of Cement Kiln Dust in Blended Cements – Alkali-Aggregate Reactive Expansion”. World Cement, Vol. 16, No. 10, pp. 386, 388-390, 392. Bhatty, M.S.Y. 1986. “Properties of Blended Cements made with Portland Cement, Cement Kiln Dust, Flyash, and Slag”. Proceedings of the 8
th International Congress on
the Chemistry of Cement, Brazil, Vol. IV, pp. 118-127. Bhatty, J.I. 1995. “Alternative Uses of Cement Kiln Dust”. Portland Cement Association, Research and Development Bulletin RP327, Skokie, IL. Bhatty J.I. 2004. “Minor Elements in Cement Manufacturing”. Innovations in Portland
Cement Manufacturing, Bhatty J. I., Miller, F. M., and Kosmatka, S.H. (editors), Portland Cement Association, 5420 Old Orchard Road, Skokie, IL 60077, pp. 403-452. Bhatty J.I. and Gajda J. 2004. “Use of Alternative Materials in Cement Manufacturing”. Innovations in Portland Cement Manufacturing, Bhatty J. I., Miller, F. M., and Kosmatka, S.H. (editors), Portland Cement Association, 5420 Old Orchard Road, Skokie, IL 60077, pp. 137-166. Brookbanks, P. 1989. “Properties of fresh concrete”. Performance of Limestone Filled
Cements, Proc. Building Research Establishment Seminar, Garston, England, pp. 4.1-4.15.
Brown, P.W., Liberman, L.O., and Frohnsdorff, G. 1984. “Kinetics of the Early Hydration of Tricalcium Aluminate in Solutions Containing Calcium Sulfate”. Journal of
the American Ceramic Society, Vol. 67, No. 12, pp. 793-795. Bye, G.C. 1999. “Portland Cement”, Second Edition, Thomas Telford, London, U.K.
261
CSA A3001. 2008. Cementitious materials for use in concrete. Canadian Standards Association, Toronto Canada. CSA A23.2-14A. 2004. Potential Expansivity of Aggregates; Procedure for Length
Change Due to Alkali-Aggregate Reaction in Concrete Prisms at 38°C. Canadian Standards Association, Toronto, Canada. CSA A23.2-27A. 2004. Standard Practice to Identify Potential for Alkali-Reactivity of
Aggregates and Measures to Avoid Deleterious Expansion in Concrete. Canadian Standards Association, Toronto, Canada. CSA A456.2-C3. 1998. Test Method for Determination of Compressive Strengths.
Canadian Standards Association, Toronto, Canada. Chatterjee A.K. 2004. “Materials Preparation and Raw Milling”. Innovations in Portland
Cement Manufacturing, Bhatty J. I., Miller, F. M., and Kosmatka, S.H. (editors), Portland Cement Association, 5420 Old Orchard Road, Skokie, IL 60077, pp. 81-136. Cochet, G. and Sorrentino, F. 1993. “Limestone filled cements: properties and uses”. Mineral Admixtures in Cement and Concrete, Ghosh, S.N., Sarkar, S.L., and Harsh, S. (editors), ABI Book Pvt. Ltd., New Delhi, India, Vol. 4, pp. 266-295.
Collepardi, M., Baldini, G., and Pauri, M. 1978. “Tricalcium Aluminate Hydration in the Presence of Lime, Gypsum or Sodium Sulfate”. Cement and Concrete Research, Vol. 8, pp. 571-580. Collins, R.J. and Emery, J.J. 1983. “Kiln Dust-Fly Ash System for Highway Bases and Subbases”. Federal Highway Administration Report FHWA/RD-82/167, U.S Department of Transportation, Washington D.C. Corish A. and Coleman, T. 1995. “Cement kiln dust”, Concrete, Vol. 29, No. 5, pp. 40–42. Damidot D. and Nonat A. 1992. “A method for determining the advancement of the hydration of C3S in diluted suspensions by means of simultaneous conductimetric and calcorimetric measurements”. Proceedings of the 9
th International Congress on the
Chemistry of Cement, New Delhi, Vol. III, pp. 227-236.
Damidot, D. and Glasser, F.P. 1995. “Investigation of the CaO–Al2O3–SiO2–H2O system at 25 °C by thermodynamic calculations”. Cement Concrete Research, Vol. 25, No. 1, pp. 22–28.
262
Detwiler, R.J, Bhatty, J.I., and Bhattacharja, S. 1996. “Supplementary Cementing Materials for use in Blended Cements”. Research and Development Bulletin RD112T, Portland Cement Association, Skokie, IL. Dodson V. 1990. “Concrete Admixtures”. Van Nostrand Reinhold. Pg 23 Dyer, T.D., Halliday, J.E., and Dhir, R.K. 1999. “An Investigation of the Hydration Chemistry of Ternary Blends Containing Cement Kiln Dust”. Journal of Materials
Science, Vol. 34, No. 20, pp. 4975-4983. El-Aleem, S.A., Abd-El-Aziz, M.A., Heikal, M., and El-Didamony, H. 2005. “Effect of Cement Kiln Dust Substitution on Chemical and Physical Properties and Compressive Strength of Portland and Slag Cements”. The Arabian Journal for Science and
Engineering, Volume 30, Number 2B, Saudi Arabia, pp. 263-273. El-Sayed, H.A., Gabr, N.A., Hanafi, S., and Mohran, M.A. 1991. “Re-utilization of by-pass kiln dust in cement manufacture”. International Conference on Blended Cement in
Construction, Sheffield, United Kingdom, pp. 84-94. EPA. 1993. “Report to Congress on Cement Kiln Dust”. U.S. Environmental Protection
Agency, Office of Solid Waste and Emergency Response, EPA-530-R-94-001.
EN 196-1. 1987. Methods of testing cement. Determination of strength. European Standard. EN 196-3. 2005. Methods of testing cement. Determination of setting time and soundness. European Standard. EN 197-1. 2000. Cement. Composition, specifications and conformity criteria for
common cements. European Standard. Frigione, G. 1983. “Gypsum in Cement”. Advances in Cement Technology, Ghosh, S.N. (editor), Pergomon Press Ltd., Oxford, pp. 485-536. Gartner, E.M., Young, J.F., Damidot, D.A., and Jawed, I. 2002. “Hydration of Portland Cement”. Structure and Performance of Cement, Second Edition, Bensted, J. and Barnes, P. (editors), Spon Press, New York, pp. 57-114. Greco C., Picciotti G., Greco R.B., and Ferreira G.M. 2004. “Fuel Selection and Use”. Innovations in Portland Cement Manufacturing, Bhatty J. I., Miller, F. M., and Kosmatka, S.H. (editors), Portland Cement Association, 5420 Old Orchard Road, Skokie, IL 60077, pp. 167-238.
263
Greening, N.R. 1967. “Some Causes for Variation in Required Amount of Air-Entraining Agent in Portland Cement Mortars” Portland Cement Association, Research and Development Bulletin RX213, Skokie, IL.
Hawkins, G.J., Bhatty, J. I., and O’Hare, A.T. 2004. “Cement Kiln Dust Generation and Management”. Innovations in Portland Cement Manufacturing, Bhatty J. I., Miller, F. M., and Kosmatka, S.H. (editors), Portland Cement Association, 5420 Old Orchard Road, Skokie, IL 60077, pp. 735-779. Hawkins, P., Tennis, P., and Detwiler, R.J. 2005. “The Use of Limestone in Portland Cement: A State of the Art Review”. Portland Cement Association, Research & Development Serial No. 2052b, Skokie, IL. Haynes, B.W. and Kramer G.W. 1982. “Characterization of U.S. cement kiln dust”. U.S.
Department of the Interior, Bureau of Mines Information Circular 8885, Pittsburgh, PA. Helmuth, R. 1987. “Fly Ash in Cement and Concrete”. Portland Cement Association, Skokie, IL. Hooton, R.D. 1990. “Effects of carbonate additions on heat of hydration and sulfate resistance”, Carbonate Additions to Cement, Klieger P. and Hooton, R.D. (editors), ASTM STP 1064, American Society for Testing and Materials, Philadelphia, PA, pp. 73-81. Hooton, R.D. and Thomas, M.D.A., 2002. “The Use of Limestone in Portland Cements: Effect on Thaumasite Form of Sulfate Attack”. Portland Cement Association, Research and Development Serial No. 2658, Skokie, IL.
Ish-Shalom, M. and Bentur, A. 1972. “Effects of Aluminate and Sulfate Contents on the Hydration and Strength of Portland Cement Pastes and Mortars”. Cement and Concrete
Research, Vol. 2, pp. 653-662. Jackson, P.J. 1998. “Portland Cement: Classification and Manufacture”. Lea’s Chemistry
of Cement and Concrete, Hewlett, P.C. (editor), John Wiley & Sons Inc., New York, pp. 25-94. Juenger, M.C.G., Monteiro, P.J.M., Gartner, E.M., and Denbeaux, G.P. 2005. “A soft X-ray microscope investigation into the effects of calcium chloride on tricalcium silicate hydration”. Cement and Concrete Research, Vol. 35, pp. 19-25.
Kessler, G.R. 1995. “Cement Kiln Dust (CKD) Methods for Reduction and Control”. IEEE Transaction on Industry Applications, Vol. 31, No. 2, pp.407-412.
264
Konsta-Gdoutos, M.S., Wang, K., Babaian, P.M., M.S., and Shah, S.P. 2001. “Effect of Cement Kiln Dust (CKD) on the Corrosion of Reinforcement in Concrete”. Third
International Conference on Concrete Under Service Conditions of Environment and
Loading (CONSEC ’01), Banthia N., Saloi, K., and Gjorv, O.E. (editors), Vancouver, British Columbia, Canada, pp. 277-284. Konsta-Gdoutos, M.S., and Shah, S.P. 2003. “Cement Kiln Dust (CKD): Characterization and Utilization in Cement and Concrete”. Celebrating Concrete: People and Practice, in
Role of Cement Science in Sustainable Development, Dhir, R.V., Newlands, M.D., and Csetenvi, L.J. (editors), pp. 59-70. Klemm, W.A. 1980. “Kiln Dust Utilization”. Martin Marietta Laboratories Report, MML TR 80-12. Baltimore, MD.
Klemm, W.A. 2005. “Cement Soundness and the Autoclave Expansion Test – An Update of the Literature”. Portland Cement Association, Research & Development Serial No. 2651, Skokie, IL.
Klemm, W.A. and Adams, L.D. 1990. “An investigation of the formation of carboaluminates”. Carbonate Additions to Cement, Klieger P. and Hooton, R.D. (editors), ASTM STP 1064, American Society for Testing and Materials, Philadelphia, PA, pp. 60–72.
Lachemi, M., Hossain, K.M.A., Shehata, M., and Thaha, W. 2008. “Controlled low strength materials incorporating cement kiln dust”. Cement & Concrete Composites, Vol. 30, No. 5, pp. 381-392. Lafarge. 2005. Lafarge Canada Inc., Internal Laboratory Report, Montreal, QC. Lafarge. 2009. Lafarge Canada Inc., Internal Laboratory Data, Montreal, QC. Lawrence, C.D. 1998a. “The Constitution and Specification of Portland Cements”. Lea’s
Chemistry of Cement and Concrete, Hewlett, P.C. (editor), John Wiley & Sons Inc., New York, pp. 131-194. Lawrence, C.D. 1998b. “Physiochemical and Mechanical Properties of Portland Cements”. Lea’s Chemistry of Cement and Concrete, Hewlett, P.C. (editor), John Wiley & Sons Inc., New York, pp. 343-420. Lehoux, P. 2006. Lafarge Canada Inc., Personal Communication, Received by O.S. Khanna. Lerch, W. 1944. “The effects of added materials on the rate of hydration of Portland Cement pastes at early ages”. Portland Cement Association, Skokie, IL.
265
Manias, G.C., 2004. “Kiln Burning Systems”. Innovations in Portland Cement
Manufacturing, Bhatty J. I., Miller, F. M., and Kosmatka, S.H. (editors), Portland Cement Association, 5420 Old Orchard Road, Skokie, IL 60077, pp. 239-268. Maslehuddin, M., Al-Amoudib, O.S.B., Shameema, M., Rehmana, M.K., and Ibrahim, M. 2008a. “Usage of cement kiln dust in cement products – Research review and preliminary investigations”. Construction and Building Materials, Vol. 22, Issue 12, pp. 2369-2375. Maslehuddin, M., Al-Amoudia, O.S.B., Rahmana, M.K., Alia, M.R., and Barrya, M.S. 2008b. “Properties of cement kiln dust concrete”. Construction and Building Materials, Vol. 23, Issue 6, pp. 2357-2361. Mattus, C.H. and Gilliam, T.M. 1994. “A Literature Review of Mixed Waste Components: Sensitivities and Effects upon Solidification/Stabilization in Cement-Based Matrices”. ORNL/TM-12656, Oak Ridge National Laboratory, Oak Ridge, TN, USA. Mostafa, N.Y., and Brown, P.W. 2005. “Heat of hydration of high reactive pozzolans in blended cements: Isothermal conduction conduction calorimetry”. Thermochimica Acta, Vol. 435, No.2, pp. 162–167.
Muller, H.P. 1977. “What is Dust? Characterization and Classification of Kiln Dust”, Holderbank Management and Consulting, Technical Center, Material Division, Aargau, Switzerland, Report No. MA 77/2505/E. Narang, K. C.; Ghosh, S. K.; Sharma, K. M. 1981. “Microstructural Characteristics of Sound and Unsound Clinkers with Varying MgO Content”. Proceedings of the Third
Annual International Conference On Cement Microscopy, Houston, Texas, pp. 140-153
Neville, A. M. 1996. “Properties of Concrete: Fourth and Final Edition”. John Wiley & Sons Inc. Nonat, A. 1994. “Interactions between chemical evolution (hydration) and physical evolution (setting) in the case of tricalcium silicate”. Materials and Structures, Vol. 27, pp. 187-195. Odler, I. 1998. “Hydration, Setting and Hardening of Portland Cement”. Lea’s Chemistry
of Cement and Concrete, Hewlett, P.C. (editor), John Wiley & Sons Inc., New York, pp. 241-298. Osbaeck, B. and Jons, E.S. 1980. “The Influence of the Content and Distribution ofAlkalies on the Hydration Properties of Portland Cement”. 7th International Congress on the Chemistry of Cement, Paris. Vol. 2, pp. 135-140.
266
Pera, J., Husson, S., and Guilhot, B.1999. “Influenec of finely ground limestone on cement hydration”. Cement and Concrete Composites, Vol. 21, pp. 99-105. Peethamparan, S. 2006. “Fundamental study of clay-cement kiln dust (CKD) interaction to determine the effectiveness of CKD as a potential clay soil stabilizer”. Ph.D.Thesis, Purdue University. Peethamparan, S., Olek, J., and Lovell, J. 2008. “Influnce of chemical and physical characteristics of cement kiln dusts (CKDs) on their hydration behaviour and potential suitability for soil stabilization”. Cement and Concrete Research, Vol. 38, pp. 803-815. Peray, K.E. 1986. “The Rotary Cement Kiln - 2nd Edition”. Chemical Publishing Company. Ramachandran, V.S. and Zhang, C. 1986. “Thermal analysis of the 3CaO.Al2O3---CaSO4.2H2O---CaCO3.H2O system”. Thermochima Acta, Vol. 106, pp. 273–282.
Ramachandran, V.S. 1988. “Thermal analysis of cement components hydrated in the presence of calcium carbonate”. Thermochima Acta, Vol. 127, pp. 385-94. Ramakrishnan, V. 1986. “Evaluation of Kiln Dust in Concrete, Flyash, Silica Fume, Slag, and Natural Pozzolans in Concrete”. American Concrete Institute, SP-91, pp. 821-839. Ramakrishnan, V., and Balaguru, P. 1987. “Durability of Concrete Containing Cement Kiln Dust”. American Concrete Institute - Concrete Durability: Katherine and Bryant
Mather International Conference, SP100-19, Vol. 1, pp. 305-321. Ravindrarajah, R.S. 1982. “Usage of cement kiln dust in concrete”. The International
Journal of Cement Composites and Lightmass Concrete, Vol. 4, No. 2, pp. 95-102. Roy, D.M. and Malek, R.I.A. 1993. “Hydration of Slag Cement”. Mineral Admixtures in
Cement and Concrete, Sarkar, S.L. and Ghosh, S.N. (editors), ABI Books Pvt. Ltd., New Delhi, pp. 84–117. Sandberg, P.J. and Roberts, L.R. 2005. “Cement-admixture interactions related to aluminate control”. 2005. Journal of ASTM International, Vol. 2, No. 6, pp. 219-232 Shi, H., Zhao, Y., and Li, W. 2002. “Effects of temperature on the hydration characteristics of free lime”. Cement and Concrete Research, Vol. 32, pp. 789-793. Shoaib, M.M., Balaha, M.M., and Abdel-Rahman, A.G. 2000. “Influence of cement kiln dust substitution on the mechanical properties of concrete”. Cement and Concrete
Research, Vol. 30, No. 2, pp. 371-377.
267
Sengun, M.Z. and Probstein, R.F. 1997. “Bimodal model of suspension viscoelasticity”. Journal of Rheology, Vol. 41, No.4, pp. 811-819. Soroka, I. 1979. “Portland Cement Paste & Concrete”. The MacMillan Press Ltd. Soroka I. and Relis M. 1983. “Effect of Added Gypsum on Compressive Strength of Portland Cement Clinker.” American Ceramic Society Bulletin, Vol. 62, No. 6, pp. 695-697. Sprung, S., Kuhlmann, K., and Ellerbrock, H.G. 1985. “Particle Size Distribution and Properties of Cement: Part II. Water Demand of Portland Cement”. Zement-Kalk-Gips,
Vol. 38, No. 9, pp. 528-534. Sprung, S. and Siebel, E. 1991. “Assessment of the suitability of limestone for producing portland limestone cement”. Zement-Kalk-Gips, Vol. 44, No. 1, pp. 1-11. Sreekrishnavilasam, A., King, S., and Santagata, M. 2006. “Characterization of fresh and landfilled cement kiln dust for reuse in construction applications”. Engineering Geology, Volume 85, Issues 1-2, pp. 165-173. Tang F.J., and Gartner, E.M. 1988. “Influence of sulphate source on Portland cement hydration”. Advances in Cement Research, Vol. 1, No. 2, pp. 67-74. Taylor, H. F. W. 1997. “Cement Chemistry - 2nd Edition”. Thomas Telford. Tennis P. and Bhatty J.I. 2006. “Characteristics of portland and blended cements: results of a survey of manufacturers”. Cement Industry Technical Conference, Conference
Record, IEEE, ISBN: 1-4244-0372-3, pp. 83-101.
Tennis P. and Kosmatka, S.H. 2004. “Cement Characteristics”. Innovations in Portland
Cement Manufacturing, Bhatty J. I., Miller, F. M., and Kosmatka, S.H. (editors), Portland Cement Association, 5420 Old Orchard Road, Skokie, IL 60077, pp. 1069-1106. Udoeyo F.F., and Hyee, A. 2002. “Strengths of Cement Kiln Dust Concrete”. Journal of
Materials in Civil Engineering, Vol. 14, Issue 6, pp. 524-526. Vernet, C. and Noworyta, G. 1992. “Mechanisms of limestone reactions in the system C3A-CaSO4.H2O-CH-CaCO3-H”. 9th
International Congress on Chemistry of Cement, New Delhi, Vol. IV, pp. 430-436.
Vuk, T., Tinta, V., Babrovsek, R., and Kaucic, V. 2001. “The Effects of Limestone Addition on, Clinker Type, and Fineness on Prperties of Portland Cement”. Cement and
Concrete Research, Vol. 31, No. 1, pp. 481-489.
268
Wang, K., Konsta-Gdoutos, M.S., and Shah, S.P. 2002. “Hydration, Rheology, and Strength of Ordinary Portland (OPC)-Cement Kiln Dust (CKD)-Slag Binders”. American
Concrete Institute Materials Journal, Vol. 99, No. 2, pp. 173-170. Wang, M.L., and Ramakrishnan, V. 1990. “Evaluation of Blended Cement, Mortar and Concrete made from Type III Cement and Kiln Dust”. Construction and Building
Materials, Vol. 4, No. 2, pp. 78-85.
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Appendix A. CKD Chemical Composition Correction Calculations
Appendix E. Isothermal Conduction Calorimetry Results
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Figure E.1 Heat of Hydration of TI cement with 10% replacement of limestone (LS), silica flour (SLX), and six CKDs (A, B, C, D, E and F).
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`
Figure E.2 Heat of Hydration of TI cement with 20% replacement of limestone (LS), silica flour (SLX), and six CKDs (A, B, C, D, E and F).
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TII CKD F 10%
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Figure E.3 Heat of Hydration of TII cement with 10% replacement of limestone (LS), silica flour (SLX), and six CKDs (A, B, C, D, E and F).
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)
TII CKD C 20%
TII LS 20%
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0 4 8 12 16 20 24
time (h)
heat
evo
luti
on
(m
W/g
)
TII CKD D2 20%
TII LS 20%
0.0
1.0
2.0
3.0
4.0
5.0
0 4 8 12 16 20 24
time (h)
heat
evo
luti
on
(m
W/g
)
TII CKD E 20%
TII LS 20%
0.0
1.0
2.0
3.0
4.0
5.0
0 4 8 12 16 20 24
time (h)
heat
evo
luti
on
(m
W/g
)
TII CKD F 20%
TII LS 20%
Figure E.4 Heat of Hydration of TII cement with 20% replacement of limestone (LS), silica flour (SLX), and six CKDs (A, B, C, D, E and F).
300
Appendix F. Mortar Flow Statistical Analysis
301
Table F.1 Mortar Flow Raw Data
TI Blends flow TII Blends flow
TI 109 TII 112
TI 107 TII 113
TI 105 TII 116
TI 107 TII 115
TI 109 TII 115
TI 108 TII 118
TI 102 TII 113
TI CKD LS 10% 110 TII CKD LS 10% 116
TI CKD LS 10% 114 TII CKD LS 10% 117
TI CKD SLX 10% 112 TII CKD SLX 10% 115
TI CKD SLX 10% 111 TII CKD SLX 10% 117
TI CKD A 10% 108 TII CKD A 10% 108
TI CKD A 10% 103 TII CKD A 10% 110
TI CKD A 10% 100 TII CKD B 10% 109
TI CKD B 10% 102 TII CKD B 10% 115
TI CKD B 10% 101 TII CKD C 10% 106
TI CKD B 10% 98 TII CKD C 10% 112
TI CKD C 10% 101 TII CKD D 10% 111
TI CKD C 10% 101 TII CKD D 10% 116
TI CKD D 10% 110 TII CKD E 10% 100
TI CKD D 10% 110 TII CKD E 10% 106
TI CKD E 10% 101 TII CKD F 10% 98
TI CKD E 10% 107 TII CKD F 10% 102
TI CKD E 10% 106 TII CKD LS 20% 116
TI CKD E 10% 96 TII CKD LS 20% 120
TI CKD E 10% 101 TII CKD SLX 20% 114
TI CKD F 10% 96 TII CKD SLX 20% 120
TI CKD F 10% 98 TII CKD A 20% 105
TI CKD F 10% 87 TII CKD A 20% 108
TI CKD F 10% 94 TII CKD B 20% 100
TI CKD LS 20% 117 TII CKD B 20% 105
TI CKD LS 20% 117 TII CKD C 20% 103
TI CKD SLX 20% 113 TII CKD C 20% 107
TI CKD SLX 20% 114 TII CKD D 20% 109
TI CKD A 20% 101 TII CKD D 20% 109
TI CKD A 20% 103 TII CKD E 20% 82
TI CKD B 20% 93 TII CKD E 20% 98
TI CKD B 20% 97 TII CKD F 20% 70
TI CKD C 20% 100 TII CKD F 20% 86
TI CKD C 20% 103 (b)
TI CKD D 20% 107
TI CKD D 20% 109
TI CKD E 20% 80
TI CKD E 20% 76
TI CKD E 20% 80
TI CKD F 20% 63
TI CKD F 20% 74
TI CKD F 20% 61
TI CKD F 20% 69
(a)
302
Oneway Analysis of Flow By Cement TI Blends
60
70
80
90
100
110
120
flow
TI
TI C
KD
A 1
0%
TI C
KD
A 2
0%
TI C
KD
B 1
0%
TI C
KD
B 2
0%
TI C
KD
C 1
0%
TI C
KD
C 2
0%
TI C
KD
D 1
0%
TI C
KD
D 2
0%
TI C
KD
E 1
0%
TI C
KD
E 2
0%
TI C
KD
F 1
0%
TI C
KD
F 2
0%
TI C
KD
LS
10%
TI C
KD
LS
20%
TI C
KD
SLX
10%
TI C
KD
SLX
20%
TI Blends
Oneway Anova Summary of Fit Rsquare 0.958229 Adj Rsquare 0.937343 Root Mean Square Error 3.363037 Mean of Response 99.63776 Observations (or Sum Wgts) 49
Analysis of Variance Source DF Sum of Squares Mean Square F Ratio Prob > F TI Blends 16 8302.4621 518.904 45.8800 <.0001 Error 32 361.9205 11.310 C. Total 48 8664.3827
Means for Oneway Anova Level Number Mean Std Error Lower 95% Upper 95% TI 7 106.571 1.2711 103.98 109.16 TI CKD A 10% 3 103.583 1.9417 99.63 107.54 TI CKD A 20% 2 101.750 2.3780 96.91 106.59 TI CKD B 10% 3 100.333 1.9417 96.38 104.29 TI CKD B 20% 2 94.625 2.3780 89.78 99.47 TI CKD C 10% 2 101.000 2.3780 96.16 105.84 TI CKD C 20% 2 101.250 2.3780 96.41 106.09 TI CKD D 10% 2 109.750 2.3780 104.91 114.59 TI CKD D 20% 2 108.000 2.3780 103.16 112.84 TI CKD E 10% 5 102.050 1.5040 98.99 105.11 TI CKD E 20% 3 78.417 1.9417 74.46 82.37 TI CKD F 10% 4 93.563 1.6815 90.14 96.99 TI CKD F 20% 4 66.313 1.6815 62.89 69.74 TI CKD LS 10% 2 112.000 2.3780 107.16 116.84 TI CKD LS 20% 2 116.500 2.3780 111.66 121.34 TI CKD SLX 10% 2 111.250 2.3780 106.41 116.09 TI CKD SLX 20% 2 113.625 2.3780 108.78 118.47 Std Error uses a pooled estimate of error variance
303
Oneway Analysis of Flow By Cement TI Blends
60
70
80
90
100
110
120
flow
TI
TI C
KD
A 1
0%
TI C
KD
A 2
0%
TI C
KD
B 1
0%
TI C
KD
B 2
0%
TI C
KD
C 1
0%
TI C
KD
C 2
0%
TI C
KD
D 1
0%
TI C
KD
D 2
0%
TI C
KD
E 1
0%
TI C
KD
E 2
0%
TI C
KD
F 1
0%
TI C
KD
F 2
0%
TI C
KD
LS
10%
TI C
KD
LS
20%
TI C
KD
SLX
10%
TI C
KD
SLX
20%
TI Blends
Means and Std Deviations Level Number Mean Std Dev Std Err Mean Lower 95% Upper 95% TI 7 106.571 2.37484 0.8976 104.38 108.77 TI CKD A 10% 3 103.583 3.66003 2.1131 94.49 112.68 TI CKD A 20% 2 101.750 1.06066 0.7500 92.22 111.28 TI CKD B 10% 3 100.333 2.08167 1.2019 95.16 105.50 TI CKD B 20% 2 94.625 2.65165 1.8750 70.80 118.45 TI CKD C 10% 2 101.000 0.00000 0.0000 101.00 101.00 TI CKD C 20% 2 101.250 2.47487 1.7500 79.01 123.49 TI CKD D 10% 2 109.750 0.35355 0.2500 106.57 112.93 TI CKD D 20% 2 108.000 1.41421 1.0000 95.29 120.71 TI CKD E 10% 5 102.050 4.49444 2.0100 96.47 107.63 TI CKD E 20% 3 78.417 2.55359 1.4743 72.07 84.76 TI CKD F 10% 4 93.563 4.70981 2.3549 86.07 101.06 TI CKD F 20% 4 66.313 5.94199 2.9710 56.86 75.77 TI CKD LS 10% 2 112.000 2.82843 2.0000 86.59 137.41 TI CKD LS 20% 2 116.500 0.00000 0.0000 116.50 116.50 TI CKD SLX 10% 2 111.250 1.06066 0.7500 101.72 120.78 TI CKD SLX 20% 2 113.625 0.88388 0.6250 105.68 121.57
304
Oneway Analysis of flow By Cement TII Blends
60
70
80
90
100
110
120
130
flow
TII
TII C
KD
A 1
0%
TII C
KD
A 2
0%
TII C
KD
B 1
0%
TII C
KD
B 2
0%
TII C
KD
C 1
0%
TII C
KD
C 2
0%
TII C
KD
D 1
0%
TII C
KD
D 2
0%
TII C
KD
E 1
0%
TII C
KD
E 2
0%
TII C
KD
F 1
0%
TII C
KD
F 2
0%
TII C
KD
LS
10%
TII C
KD
LS
20%
TII C
KD
SLX
10%
TII C
KD
SLX
20%
TII Blends
Oneway Anova Summary of Fit Rsquare 0.902038 Adj Rsquare 0.830793 Root Mean Square Error 4.337334 Mean of Response 107.8205 Observations (or Sum Wgts) 39
Analysis of Variance Source DF Sum of Squares Mean Square F Ratio Prob > F TII Blends 16 3810.9643 238.185 12.6610 <.0001 Error 22 413.8743 18.812 C. Total 38 4224.8386
Means for Oneway Anova Level Number Mean Std Error Lower 95% Upper 95% TII 7 114.429 1.6394 111.03 117.83 TII CKD A 10% 2 108.750 3.0670 102.39 115.11 TII CKD A 20% 2 106.375 3.0670 100.01 112.74 TII CKD B 10% 2 111.625 3.0670 105.26 117.99 TII CKD B 20% 2 102.375 3.0670 96.01 108.74 TII CKD C 10% 2 108.950 3.0670 102.59 115.31 TII CKD C 20% 2 104.750 3.0670 98.39 111.11 TII CKD D 10% 2 113.375 3.0670 107.01 119.74 TII CKD D 20% 2 109.000 3.0670 102.64 115.36 TII CKD E 10% 2 103.000 3.0670 96.64 109.36 TII CKD E 20% 2 89.625 3.0670 83.26 95.99 TII CKD F 10% 2 99.625 3.0670 93.26 105.99 TII CKD F 20% 2 77.500 3.0670 71.14 83.86 TII CKD LS 10% 2 116.375 3.0670 110.01 122.74 TII CKD LS 20% 2 117.875 3.0670 111.51 124.24 TII CKD SLX 10% 2 116.000 3.0670 109.64 122.36 TII CKD SLX 20% 2 116.800 3.0670 110.44 123.16 Std Error uses a pooled estimate of error variance
305
Oneway Analysis of flow By Cement TII Blends
60
70
80
90
100
110
120
130
flow
TII
TII C
KD
A 1
0%
TII C
KD
A 2
0%
TII C
KD
B 1
0%
TII C
KD
B 2
0%
TII C
KD
C 1
0%
TII C
KD
C 2
0%
TII C
KD
D 1
0%
TII C
KD
D 2
0%
TII C
KD
E 1
0%
TII C
KD
E 2
0%
TII C
KD
F 1
0%
TII C
KD
F 2
0%
TII C
KD
LS
10%
TII C
KD
LS
20%
TII C
KD
SLX
10%
TII C
KD
SLX
20%
TII Blends
Means and Std Deviations Level Number Mean Std Dev Std Err Mean Lower 95% Upper 95% TII 7 114.429 1.9133 0.7232 112.7 116.20 TII CKD A 10% 2 108.750 1.4142 1.0000 96.0 121.46 TII CKD A 20% 2 106.375 2.6517 1.8750 82.6 130.20 TII CKD B 10% 2 111.625 4.4194 3.1250 71.9 151.33 TII CKD B 20% 2 102.375 3.7123 2.6250 69.0 135.73 TII CKD C 10% 2 108.950 3.9598 2.8000 73.4 144.53 TII CKD C 20% 2 104.750 2.8284 2.0000 79.3 130.16 TII CKD D 10% 2 113.375 4.0659 2.8750 76.8 149.91 TII CKD D 20% 2 109.000 0.0000 0.0000 109.0 109.00 TII CKD E 10% 2 103.000 3.8891 2.7500 68.1 137.94 TII CKD E 20% 2 89.625 11.1369 7.8750 -10.4 189.69 TII CKD F 10% 2 99.625 2.6517 1.8750 75.8 123.45 TII CKD F 20% 2 77.500 11.3137 8.0000 -24.1 179.15 TII CKD LS 10% 2 116.375 0.5303 0.3750 111.6 121.14 TII CKD LS 20% 2 117.875 3.3588 2.3750 87.7 148.05 TII CKD SLX 10% 2 116.000 1.7678 1.2500 100.1 131.88 TII CKD SLX 20% 2 116.800 4.5255 3.2000 76.1 157.46
306
Appendix G. Mortar Compressive Strength Statistical Analysis
307
Table G.1 Individual Compressive Strength (MPa)
TI Blends 1d 3d 7d 28d 90d TII Blends 1d 3d 7d 28d 90d
Oneway Anova Summary of Fit Rsquare 0.986739 Adj Rsquare 0.980499 Root Mean Square Error 0.285478 Mean of Response 13.99275 Observations (or Sum Wgts) 51
Analysis of Variance Source DF Sum of Squares Mean Square F Ratio Prob > F TI Blends 16 206.18427 12.8865 158.1217 <.0001 Error 34 2.77091 0.0815 C. Total 50 208.95518
Means for Oneway Anova Level Number Mean Std Error Lower 95% Upper 95% TI 3 15.9338 0.16482 15.599 16.269 TI CKD A 10% 3 17.8681 0.16482 17.533 18.203 TI CKD A 20% 3 15.7455 0.16482 15.411 16.080 TI CKD B 10% 3 16.1906 0.16482 15.856 16.526 TI CKD B 20% 3 14.3424 0.16482 14.007 14.677 TI CKD C 10% 3 15.0781 0.16482 14.743 15.413 TI CKD C 20% 3 13.3155 0.16482 12.981 13.650 TI CKD D 10% 3 11.6558 0.16482 11.321 11.991 TI CKD D 20% 3 10.4066 0.16482 10.072 10.742 TI CKD E 10% 3 14.7875 0.16482 14.453 15.122 TI CKD E 20% 3 10.8339 0.16482 10.499 11.169 TI CKD F 10% 3 14.3085 0.16482 13.974 14.643 TI CKD F 20% 3 11.5306 0.16482 11.196 11.866 TI CKD LS 10% 3 14.8897 0.16482 14.555 15.225 TI CKD LS 20% 3 12.4937 0.16482 12.159 12.829 TI CKD SLX 10% 3 15.2493 0.16482 14.914 15.584 TI CKD SLX 20% 3 13.2472 0.16482 12.912 13.582 Std Error uses a pooled estimate of error variance
310
Oneway Analysis of 1d By Cement TII Blends
10
11
12
13
14
15
16
1d
TII
TII C
KD
A 1
0%
TII C
KD
A 2
0%
TII C
KD
B 1
0%
TII C
KD
B 2
0%
TII C
KD
C 1
0%
TII C
KD
C 2
0%
TII C
KD
D 1
0%
TII C
KD
D 2
0%
TII C
KD
E 1
0%
TII C
KD
E 2
0%
TII C
KD
F 1
0%
TII C
KD
F 2
0%
TII C
KD
LS
10%
TII C
KD
LS
20%
TII C
KD
SLX
10%
TII C
KD
SLX
20%
TII Blends
Oneway Anova Summary of Fit Rsquare 0.949956 Adj Rsquare 0.926405 Root Mean Square Error 0.40549 Mean of Response 12.94315 Observations (or Sum Wgts) 51
Analysis of Variance Source DF Sum of Squares Mean Square F Ratio Prob > F TII Blends 16 106.11768 6.63235 40.3373 <.0001 Error 34 5.59036 0.16442 C. Total 50 111.70804
Means for Oneway Anova Level Number Mean Std Error Lower 95% Upper 95% TII 3 13.8112 0.23411 13.335 14.287 TII CKD A 10% 3 15.0448 0.23411 14.569 15.521 TII CKD A 20% 3 13.2991 0.23411 12.823 13.775 TII CKD B 10% 3 14.6336 0.23411 14.158 15.109 TII CKD B 20% 3 14.0512 0.23411 13.575 14.527 TII CKD C 10% 3 14.7186 0.23411 14.243 15.194 TII CKD C 20% 3 12.1514 0.23411 11.676 12.627 TII CKD D 10% 3 12.8365 0.23411 12.361 13.312 TII CKD D 20% 3 10.7483 0.23411 10.273 11.224 TII CKD E 10% 3 15.0121 0.23411 14.536 15.488 TII CKD E 20% 3 11.0906 0.23411 10.615 11.566 TII CKD F 10% 3 13.7256 0.23411 13.250 14.201 TII CKD F 20% 3 11.8091 0.23411 11.333 12.285 TII CKD LS 10% 3 12.8187 0.23411 12.343 13.295 TII CKD LS 20% 3 11.0223 0.23411 10.547 11.498 TII CKD SLX 10% 3 12.1864 0.23411 11.711 12.662 TII CKD SLX 20% 3 11.0740 0.23411 10.598 11.550 Std Error uses a pooled estimate of error variance
311
Oneway Analysis of 3d By Cement TI Blends
16
18
20
22
24
26
28
30
3d
TI
TI C
KD
A 1
0%
TI C
KD
A 2
0%
TI C
KD
B 1
0%
TI C
KD
B 2
0%
TI C
KD
C 1
0%
TI C
KD
C 2
0%
TI C
KD
D 1
0%
TI C
KD
D 2
0%
TI C
KD
E 1
0%
TI C
KD
E 2
0%
TI C
KD
F 1
0%
TI C
KD
F 2
0%
TI C
KD
LS
10%
TI C
KD
LS
20%
TI C
KD
SLX
10%
TI C
KD
SLX
20%
TI Blends
Oneway Anova Summary of Fit Rsquare 0.962887 Adj Rsquare 0.945423 Root Mean Square Error 0.577871 Mean of Response 24.55801 Observations (or Sum Wgts) 51
Analysis of Variance Source DF Sum of Squares Mean Square F Ratio Prob > F TI Blends 16 294.57345 18.4108 55.1331 <.0001 Error 34 11.35377 0.3339 C. Total 50 305.92722
Means for Oneway Anova Level Number Mean Std Error Lower 95% Upper 95% TI 3 25.2785 0.33363 24.601 25.957 TI CKD A 10% 3 27.9824 0.33363 27.304 28.660 TI CKD A 20% 3 25.2596 0.33363 24.582 25.938 TI CKD B 10% 3 26.3738 0.33363 25.696 27.052 TI CKD B 20% 3 23.7899 0.33363 23.112 24.468 TI CKD C 10% 3 26.5110 0.33363 25.833 27.189 TI CKD C 20% 3 24.5945 0.33363 23.917 25.273 TI CKD D 10% 3 24.3378 0.33363 23.660 25.016 TI CKD D 20% 3 17.9020 0.33363 17.224 18.580 TI CKD E 10% 3 26.6649 0.33363 25.987 27.343 TI CKD E 20% 3 22.1123 0.33363 21.434 22.790 TI CKD F 10% 3 27.3708 0.33363 26.693 28.049 TI CKD F 20% 3 23.6871 0.33363 23.009 24.365 TI CKD LS 10% 3 26.4255 0.33363 25.747 27.103 TI CKD LS 20% 3 23.1220 0.33363 22.444 23.800 TI CKD SLX 10% 3 24.4745 0.33363 23.796 25.153 TI CKD SLX 20% 3 21.5995 0.33363 20.921 22.277 Std Error uses a pooled estimate of error variance
312
Oneway Analysis of 3d By Cement TII Blends
15
16
17
18
19
20
21
22
23
24
25
3d
TII
TII C
KD
A 1
0%
TII C
KD
A 2
0%
TII C
KD
B 1
0%
TII C
KD
B 2
0%
TII C
KD
C 1
0%
TII C
KD
C 2
0%
TII C
KD
D 1
0%
TII C
KD
D 2
0%
TII C
KD
E 1
0%
TII C
KD
E 2
0%
TII C
KD
F 1
0%
TII C
KD
F 2
0%
TII C
KD
LS
10%
TII C
KD
LS
20%
TII C
KD
SLX
10%
TII C
KD
SLX
20%
TII Blends
Oneway Anova Summary of Fit Rsquare 0.949156 Adj Rsquare 0.92523 Root Mean Square Error 0.627122 Mean of Response 21.07458 Observations (or Sum Wgts) 51
Analysis of Variance Source DF Sum of Squares Mean Square F Ratio Prob > F TII Blends 16 249.62152 15.6013 39.6696 <.0001 Error 34 13.37159 0.3933 C. Total 50 262.99311
Means for Oneway Anova Level Number Mean Std Error Lower 95% Upper 95% TII 3 22.7969 0.36207 22.061 23.533 TII CKD A 10% 3 23.5504 0.36207 22.815 24.286 TII CKD A 20% 3 21.8217 0.36207 21.086 22.558 TII CKD B 10% 3 23.3109 0.36207 22.575 24.047 TII CKD B 20% 3 21.7017 0.36207 20.966 22.438 TII CKD C 10% 3 23.3448 0.36207 22.609 24.081 TII CKD C 20% 3 21.0005 0.36207 20.265 21.736 TII CKD D 10% 3 21.3422 0.36207 20.606 22.078 TII CKD D 20% 3 16.0878 0.36207 15.352 16.824 TII CKD E 10% 3 23.9438 0.36207 23.208 24.680 TII CKD E 20% 3 17.9704 0.36207 17.235 18.706 TII CKD F 10% 3 22.8825 0.36207 22.147 23.618 TII CKD F 20% 3 20.4526 0.36207 19.717 21.188 TII CKD LS 10% 3 21.5484 0.36207 20.813 22.284 TII CKD LS 20% 3 18.4160 0.36207 17.680 19.152 TII CKD SLX 10% 3 19.7674 0.36207 19.032 20.503 TII CKD SLX 20% 3 18.3299 0.36207 17.594 19.066 Std Error uses a pooled estimate of error variance
313
Oneway Analysis of 7d By Cement TI Blends
20
22
24
26
28
30
32
34
7d
TI
TI C
KD
A 1
0%
TI C
KD
A 2
0%
TI C
KD
B 1
0%
TI C
KD
B 2
0%
TI C
KD
C 1
0%
TI C
KD
C 2
0%
TI C
KD
D 1
0%
TI C
KD
D 2
0%
TI C
KD
E 1
0%
TI C
KD
E 2
0%
TI C
KD
F 1
0%
TI C
KD
F 2
0%
TI C
KD
LS
10%
TI C
KD
LS
20%
TI C
KD
SLX
10%
TI C
KD
SLX
20%
TI Blends
Oneway Anova Summary of Fit Rsquare 0.936064 Adj Rsquare 0.905977 Root Mean Square Error 0.823119 Mean of Response 29.20319 Observations (or Sum Wgts) 51
Analysis of Variance Source DF Sum of Squares Mean Square F Ratio Prob > F TI Blends 16 337.26034 21.0788 31.1114 <.0001 Error 34 23.03587 0.6775 C. Total 50 360.29621
Means for Oneway Anova Level Number Mean Std Error Lower 95% Upper 95% TI 3 28.7704 0.47523 27.805 29.736 TI CKD A 10% 3 32.3989 0.47523 31.433 33.365 TI CKD A 20% 3 29.0099 0.47523 28.044 29.976 TI CKD B 10% 3 29.9851 0.47523 29.019 30.951 TI CKD B 20% 3 27.6918 0.47523 26.726 28.658 TI CKD C 10% 3 29.7117 0.47523 28.746 30.677 TI CKD C 20% 3 28.4964 0.47523 27.531 29.462 TI CKD D 10% 3 32.1422 0.47523 31.176 33.108 TI CKD D 20% 3 22.6258 0.47523 21.660 23.592 TI CKD E 10% 3 32.4000 0.47523 31.434 33.366 TI CKD E 20% 3 28.5820 0.47523 27.616 29.548 TI CKD F 10% 3 31.7999 0.47523 30.834 32.766 TI CKD F 20% 3 31.9705 0.47523 31.005 32.936 TI CKD LS 10% 3 30.2762 0.47523 29.310 31.242 TI CKD LS 20% 3 27.0756 0.47523 26.110 28.041 TI CKD SLX 10% 3 28.1364 0.47523 27.171 29.102 TI CKD SLX 20% 3 25.3813 0.47523 24.416 26.347 Std Error uses a pooled estimate of error variance
314
Oneway Analysis of 7d By Cement TII Blends
18
20
22
24
26
28
30
32
7d
TII
TII C
KD
A 1
0%
TII C
KD
A 2
0%
TII C
KD
B 1
0%
TII C
KD
B 2
0%
TII C
KD
C 1
0%
TII C
KD
C 2
0%
TII C
KD
D 1
0%
TII C
KD
D 2
0%
TII C
KD
E 1
0%
TII C
KD
E 2
0%
TII C
KD
F 1
0%
TII C
KD
F 2
0%
TII C
KD
LS
10%
TII C
KD
LS
20%
TII C
KD
SLX
10%
TII C
KD
SLX
20%
TII Blends
Oneway Anova Summary of Fit Rsquare 0.935972 Adj Rsquare 0.905841 Root Mean Square Error 0.856028 Mean of Response 26.25454 Observations (or Sum Wgts) 51
Analysis of Variance Source DF Sum of Squares Mean Square F Ratio Prob > F TII Blends 16 364.20427 22.7628 31.0634 <.0001 Error 34 24.91466 0.7328 C. Total 50 389.11893
Means for Oneway Anova Level Number Mean Std Error Lower 95% Upper 95% TII 3 27.7091 0.49423 26.705 28.713 TII CKD A 10% 3 28.6676 0.49423 27.663 29.672 TII CKD A 20% 3 26.0320 0.49423 25.028 27.036 TII CKD B 10% 3 27.9807 0.49423 26.976 28.985 TII CKD B 20% 3 26.8016 0.49423 25.797 27.806 TII CKD C 10% 3 27.1790 0.49423 26.175 28.183 TII CKD C 20% 3 25.3302 0.49423 24.326 26.335 TII CKD D 10% 3 26.0923 0.49423 25.088 27.097 TII CKD D 20% 3 20.4697 0.49423 19.465 21.474 TII CKD E 10% 3 29.7289 0.49423 28.725 30.733 TII CKD E 20% 3 24.9839 0.49423 23.980 25.988 TII CKD F 10% 3 29.1638 0.49423 28.159 30.168 TII CKD F 20% 3 28.4448 0.49423 27.440 29.449 TII CKD LS 10% 3 28.7359 0.49423 27.732 29.740 TII CKD LS 20% 3 24.6962 0.49423 23.692 25.701 TII CKD SLX 10% 3 23.8588 0.49423 22.854 24.863 TII CKD SLX 20% 3 20.4526 0.49423 19.448 21.457 Std Error uses a pooled estimate of error variance
315
Oneway Analysis of 28d By Cement TI Blends
28
30
32
34
36
38
40
42
28d
TI
TI C
KD
A 1
0%
TI C
KD
A 2
0%
TI C
KD
B 1
0%
TI C
KD
B 2
0%
TI C
KD
C 1
0%
TI C
KD
C 2
0%
TI C
KD
D 1
0%
TI C
KD
D 2
0%
TI C
KD
E 1
0%
TI C
KD
E 2
0%
TI C
KD
F 1
0%
TI C
KD
F 2
0%
TI C
KD
LS
10%
TI C
KD
LS
20%
TI C
KD
SLX
10%
TI C
KD
SLX
20%
TI Blends
Oneway Anova Summary of Fit Rsquare 0.872309 Adj Rsquare 0.812218 Root Mean Square Error 1.107147 Mean of Response 35.90854 Observations (or Sum Wgts) 51
Analysis of Variance Source DF Sum of Squares Mean Square F Ratio Prob > F TI Blends 16 284.70643 17.7942 14.5167 <.0001 Error 34 41.67630 1.2258 C. Total 50 326.38273
Means for Oneway Anova Level Number Mean Std Error Lower 95% Upper 95% TI 3 36.1636 0.63921 34.865 37.463 TI CKD A 10% 3 37.7039 0.63921 36.405 39.003 TI CKD A 20% 3 34.3148 0.63921 33.016 35.614 TI CKD B 10% 3 37.0026 0.63921 35.704 38.302 TI CKD B 20% 3 33.8198 0.63921 32.521 35.119 TI CKD C 10% 3 36.7120 0.63921 35.413 38.011 TI CKD C 20% 3 32.2796 0.63921 30.981 33.579 TI CKD D 10% 3 41.1957 0.63921 39.897 42.495 TI CKD D 20% 3 36.4965 0.63921 35.197 37.796 TI CKD E 10% 3 36.5164 0.63921 35.217 37.815 TI CKD E 20% 3 36.0209 0.63921 34.722 37.320 TI CKD F 10% 3 39.3131 0.63921 38.014 40.612 TI CKD F 20% 3 35.9924 0.63921 34.693 37.291 TI CKD LS 10% 3 37.2421 0.63921 35.943 38.541 TI CKD LS 20% 3 33.1007 0.63921 31.802 34.400 TI CKD SLX 10% 3 35.0168 0.63921 33.718 36.316 TI CKD SLX 20% 3 31.5541 0.63921 30.255 32.853 Std Error uses a pooled estimate of error variance
316
Oneway Analysis of 28d By Cement TII Blends
26
28
30
32
34
36
38
40
42
28d
TII
TII C
KD
A 1
0%
TII C
KD
A 2
0%
TII C
KD
B 1
0%
TII C
KD
B 2
0%
TII C
KD
C 1
0%
TII C
KD
C 2
0%
TII C
KD
D 1
0%
TII C
KD
D 2
0%
TII C
KD
E 1
0%
TII C
KD
E 2
0%
TII C
KD
F 1
0%
TII C
KD
F 2
0%
TII C
KD
LS
10%
TII C
KD
LS
20%
TII C
KD
SLX
10%
TII C
KD
SLX
20%
TII Blends
Oneway Anova Summary of Fit Rsquare 0.929448 Adj Rsquare 0.896247 Root Mean Square Error 0.926892 Mean of Response 33.87856 Observations (or Sum Wgts) 51
Analysis of Variance Source DF Sum of Squares Mean Square F Ratio Prob > F TII Blends 16 384.81536 24.0510 27.9946 <.0001 Error 34 29.21035 0.8591 C. Total 50 414.02571
Means for Oneway Anova Level Number Mean Std Error Lower 95% Upper 95% TII 3 36.9510 0.53514 35.863 38.038 TII CKD A 10% 3 36.0786 0.53514 34.991 37.166 TII CKD A 20% 3 32.4334 0.53514 31.346 33.521 TII CKD B 10% 3 35.3429 0.53514 34.255 36.430 TII CKD B 20% 3 30.9643 0.53514 29.877 32.052 TII CKD C 10% 3 34.4182 0.53514 33.331 35.506 TII CKD C 20% 3 30.9103 0.53514 29.823 31.998 TII CKD D 10% 3 34.7772 0.53514 33.690 35.865 TII CKD D 20% 3 33.1863 0.53514 32.099 34.274 TII CKD E 10% 3 36.9343 0.53514 35.847 38.022 TII CKD E 20% 3 33.7336 0.53514 32.646 34.821 TII CKD F 10% 3 38.3890 0.53514 37.302 39.477 TII CKD F 20% 3 36.2433 0.53514 35.156 37.331 TII CKD LS 10% 3 35.7363 0.53514 34.649 36.824 TII CKD LS 20% 3 30.4135 0.53514 29.326 31.501 TII CKD SLX 10% 3 31.3548 0.53514 30.267 32.442 TII CKD SLX 20% 3 28.0686 0.53514 26.981 29.156 Std Error uses a pooled estimate of error variance
317
Oneway Analysis of 90d By Cement TI Blends
35
40
45
50
90d
TI
TI C
KD
A 1
0%
TI C
KD
A 2
0%
TI C
KD
B 1
0%
TI C
KD
B 2
0%
TI C
KD
C 1
0%
TI C
KD
C 2
0%
TI C
KD
D 1
0%
TI C
KD
D 2
0%
TI C
KD
E 1
0%
TI C
KD
E 2
0%
TI C
KD
F 1
0%
TI C
KD
F 2
0%
TI C
KD
LS
10%
TI C
KD
LS
20%
TI C
KD
SLX
10%
TI C
KD
SLX
20%
TI Blends
Oneway Anova Summary of Fit Rsquare 0.927228 Adj Rsquare 0.892982 Root Mean Square Error 1.012278 Mean of Response 41.20939 Observations (or Sum Wgts) 51
Analysis of Variance Source DF Sum of Squares Mean Square F Ratio Prob > F TI Blends 16 443.91665 27.7448 27.0758 <.0001 Error 34 34.84005 1.0247 C. Total 50 478.75670
Means for Oneway Anova Level Number Mean Std Error Lower 95% Upper 95% TI 3 40.7386 0.58444 39.551 41.926 TI CKD A 10% 3 44.3447 0.58444 43.157 45.532 TI CKD A 20% 3 40.5623 0.58444 39.375 41.750 TI CKD B 10% 3 41.4524 0.58444 40.265 42.640 TI CKD B 20% 3 39.5360 0.58444 38.348 40.724 TI CKD C 10% 3 39.4153 0.58444 38.228 40.603 TI CKD C 20% 3 37.5844 0.58444 36.397 38.772 TI CKD D 10% 3 46.0068 0.58444 44.819 47.195 TI CKD D 20% 3 45.4000 0.58444 44.212 46.588 TI CKD E 10% 3 43.8101 0.58444 42.622 44.998 TI CKD E 20% 3 42.6517 0.58444 41.464 43.839 TI CKD F 10% 3 41.4140 0.58444 40.226 42.602 TI CKD F 20% 3 42.3845 0.58444 41.197 43.572 TI CKD LS 10% 3 44.0357 0.58444 42.848 45.223 TI CKD LS 20% 3 37.6005 0.58444 36.413 38.788 TI CKD SLX 10% 3 38.7789 0.58444 37.591 39.967 TI CKD SLX 20% 3 34.8438 0.58444 33.656 36.032 Std Error uses a pooled estimate of error variance
318
Oneway Analysis of 90d By Cement TII Blends
30
32.5
35
37.5
40
42.5
45
90d
TII
TII C
KD
A 1
0%
TII C
KD
A 2
0%
TII C
KD
B 1
0%
TII C
KD
B 2
0%
TII C
KD
C 1
0%
TII C
KD
C 2
0%
TII C
KD
D 1
0%
TII C
KD
D 2
0%
TII C
KD
E 1
0%
TII C
KD
E 2
0%
TII C
KD
F 1
0%
TII C
KD
F 2
0%
TII C
KD
LS
10%
TII C
KD
LS
20%
TII C
KD
SLX
10%
TII C
KD
SLX
20%
TII Blends
Oneway Anova Summary of Fit Rsquare 0.909702 Adj Rsquare 0.867209 Root Mean Square Error 1.195474 Mean of Response 39.72669 Observations (or Sum Wgts) 51
Analysis of Variance Source DF Sum of Squares Mean Square F Ratio Prob > F TII Blends 16 489.53341 30.5958 21.4083 <.0001 Error 34 48.59138 1.4292 C. Total 50 538.12478
Means for Oneway Anova Level Number Mean Std Error Lower 95% Upper 95% TII 3 42.3254 0.69021 40.923 43.728 TII CKD A 10% 3 41.9659 0.69021 40.563 43.369 TII CKD A 20% 3 37.8923 0.69021 36.490 39.295 TII CKD B 10% 3 42.0681 0.69021 40.665 43.471 TII CKD B 20% 3 38.2518 0.69021 36.849 39.654 TII CKD C 10% 3 41.4524 0.69021 40.050 42.855 TII CKD C 20% 3 37.9267 0.69021 36.524 39.329 TII CKD D 10% 3 42.2565 0.69021 40.854 43.659 TII CKD D 20% 3 41.8803 0.69021 40.478 43.283 TII CKD E 10% 3 43.1467 0.69021 41.744 44.549 TII CKD E 20% 3 39.6382 0.69021 38.236 41.041 TII CKD F 10% 3 42.3891 0.69021 40.986 43.792 TII CKD F 20% 3 40.2544 0.69021 38.852 41.657 TII CKD LS 10% 3 41.2468 0.69021 39.844 42.650 TII CKD LS 20% 3 34.8633 0.69021 33.461 36.266 TII CKD SLX 10% 3 36.1504 0.69021 34.748 37.553 TII CKD SLX 20% 3 31.6454 0.69021 30.243 33.048 Std Error uses a pooled estimate of error variance
319
Appendix H. Mortar Expansion in Limewater Statistical Analysis
320
Table H.1 Individual Expansions in Limewater of TI Blends
TI Blends Sample ID 14d TI Blends Sample ID 14d
TI 1 0.001 TI CKD D 10% 1 0.043
TI 2 0.000 TI CKD D 10% 2 0.040
TI 3 0.002 TI CKD D 10% 3 0.046
TI 4 0.001 average 0.001 TI CKD D 10% 4 0.044 average 0.043
TI 1 0.010 TI CKD E 10% 1 0.031
TI 2 0.008 TI CKD E 10% 2 0.029
TI 3 0.007 TI CKD E 10% 3 0.030
TI 4 0.009 average 0.008 TI CKD E 10% 4 0.029 average 0.030
TI 1 0.008 TI CKD F 10% 1 0.015
TI 2 0.008 TI CKD F 10% 2 0.017
TI 3 0.008 TI CKD F 10% 3 0.017
TI 4 0.009 average 0.008 TI CKD F 10% 4 0.017 average 0.016
TI 1 0.003 TI CKD LS 20% 1 0.006
TI 2 0.005 TI CKD LS 20% 2 0.006
TI 3 0.005 TI CKD LS 20% 3 0.006
TI 4 0.005 average 0.004 TI CKD LS 20% 4 0.006 average 0.006
TI 1 0.005 TI CKD LS 20% 1 0.003
TI 2 0.004 TI CKD LS 20% 2 0.004
TI 3 0.005 TI CKD LS 20% 3 0.003
TI 4 0.005 average 0.005 TI CKD LS 20% 4 0.003 average 0.003
TI 1 0.004 TI CKD SLX 20% 1 0.002
TI 2 0.004 TI CKD SLX 20% 2 0.004
TI 3 0.004 TI CKD SLX 20% 3 0.004
TI 4 0.003 average 0.004 TI CKD SLX 20% 4 0.004 average 0.004
TI CKD LS 10% 1 0.009 TI CKD SLX 20% 1 0.005
TI CKD LS 10% 2 0.010 TI CKD SLX 20% 2 0.005
TI CKD LS 10% 3 0.010 TI CKD SLX 20% 3 0.005
TI CKD LS 10% 4 0.009 average 0.009 TI CKD SLX 20% 4 0.006 average 0.005
TI CKD LS 10% 1 0.004 TI CKD A 20% 1 0.014
TI CKD LS 10% 2 0.006 TI CKD A 20% 2 0.015
TI CKD LS 10% 3 0.004 TI CKD A 20% 3 0.014
TI CKD LS 10% 4 0.004 average 0.004 TI CKD A 20% 4 0.014 average 0.014
TI CKD SLX 10% 1 0.005 TI CKD B 20% 1 0.011
TI CKD SLX 10% 2 0.006 TI CKD B 20% 2 0.010
TI CKD SLX 10% 3 0.005 TI CKD B 20% 3 0.010
TI CKD SLX 10% 4 0.006 average 0.006 TI CKD B 20% 4 0.012 average 0.011
TI CKD SLX 10% 1 0.006 TI CKD C 20% 1 0.012
TI CKD SLX 10% 2 0.006 TI CKD C 20% 2 0.012
TI CKD SLX 10% 3 0.005 TI CKD C 20% 3 0.013
TI CKD SLX 10% 4 0.005 average 0.005 TI CKD C 20% 4 0.012 average 0.012
TI CKD A 10% 1 0.009 TI CKD D 20% 1 0.1390
TI CKD A 10% 2 0.012 TI CKD D 20% 2 0.1330
TI CKD A 10% 3 0.009 TI CKD D 20% 3 0.1260
TI CKD A 10% 4 0.009 average 0.010 TI CKD D 20% 4 0.1270 average 0.131
TI CKD B 10% 1 0.007 TI CKD D 20% 1 0.124
TI CKD B 10% 2 0.007 TI CKD D 20% 2 0.126
TI CKD B 10% 3 0.009 TI CKD D 20% 3 0.124
TI CKD B 10% 4 0.008 average 0.008 TI CKD D 20% 4 0.126 average 0.125
TI CKD C 10% 1 0.007 TI CKD E 20% 1 0.067
TI CKD C 10% 2 0.007 TI CKD E 20% 2 0.062
TI CKD C 10% 3 0.006 TI CKD E 20% 3 0.071
TI CKD C 10% 4 0.007 average 0.007 TI CKD E 20% 4 0.070 average 0.068
TI CKD D 10% 1 0.058 TI CKD F 20% 1 0.033
TI CKD D 10% 2 0.059 TI CKD F 20% 2 0.034
TI CKD D 10% 3 0.056 TI CKD F 20% 3 0.033
TI CKD D 10% 4 0.055 average 0.057 TI CKD F 20% 4 0.034 average 0.034
TI CKD D 10% 1 0.059
TI CKD D 10% 2 0.057
TI CKD D 10% 3 0.058
TI CKD D 10% 4 0.059 average 0.058
321
Oneway Analysis of 14d By Cement TI Blends
-0.01
0.01
0.03
0.05
0.07
0.09
0.11
0.13
14d
TI
TI C
KD
A 1
0%
TI C
KD
A 2
0%
TI C
KD
B 1
0%
TI C
KD
B 2
0%
TI C
KD
C 1
0%
TI C
KD
C 2
0%
TI C
KD
D 1
0%
TI C
KD
D 2
0%
TI C
KD
E 1
0%
TI C
KD
E 2
0%
TI C
KD
F 1
0%
TI C
KD
F 2
0%
TI C
KD
LS
10%
TI C
KD
LS
20%
TI C
KD
SLX
10%
TI C
KD
SLX
20%
TI Blends
Oneway Anova Summary of Fit Rsquare 0.991545 Adj Rsquare 0.990179 Root Mean Square Error 0.003338 Mean of Response 0.024043 Observations (or Sum Wgts) 116
Analysis of Variance Source DF Sum of Squares Mean Square F Ratio Prob > F TI Blends 16 0.12937762 0.008086 725.6601 <.0001 Error 99 0.00110317 0.000011 C. Total 115 0.13048078
Means for Oneway Anova Level Number Mean Std Error Lower 95% Upper 95% TI 24 0.005125 0.00068 0.00377 0.00648 TI CKD A 10% 4 0.009750 0.00167 0.00644 0.01306 TI CKD A 20% 4 0.014250 0.00167 0.01094 0.01756 TI CKD B 10% 4 0.007750 0.00167 0.00444 0.01106 TI CKD B 20% 4 0.010750 0.00167 0.00744 0.01406 TI CKD C 10% 4 0.006750 0.00167 0.00344 0.01006 TI CKD C 20% 4 0.012250 0.00167 0.00894 0.01556 TI CKD D 10% 12 0.052833 0.00096 0.05092 0.05475 TI CKD D 20% 8 0.128125 0.00118 0.12578 0.13047 TI CKD E 10% 4 0.029750 0.00167 0.02644 0.03306 TI CKD E 20% 4 0.067500 0.00167 0.06419 0.07081 TI CKD F 10% 4 0.016500 0.00167 0.01319 0.01981 TI CKD F 20% 4 0.033500 0.00167 0.03019 0.03681 TI CKD LS 10% 8 0.007000 0.00118 0.00466 0.00934 TI CKD LS 20% 8 0.004625 0.00118 0.00228 0.00697 TI CKD SLX 10% 8 0.005500 0.00118 0.00316 0.00784 TI CKD SLX 20% 8 0.004375 0.00118 0.00203 0.00672 Std Error uses a pooled estimate of error variance
322
Table H.2 Individual Expansions in Limewater of TII Blends
TII Blends Sample 14d
TII 1 0.0070
TII 2 0.0080
TII 3 0.0080
TII 4 0.0080 average 0.008
TII 1 0.0040
TII 2 0.0060
TII 3 0.0050
TII 4 0.0060 average 0.005
TII CKD LS 10% 1 0.0060
TII CKD LS 10% 2 0.0050
TII CKD LS 10% 3 0.0050
TII CKD LS 10% 4 0.0060 average 0.005
TII CKD SLX 10% 1 0.0080
TII CKD SLX 10% 2 0.0070
TII CKD SLX 10% 3 0.0080
TII CKD SLX 10% 4 0.0070 average 0.008
TII CKD A 10% 1 0.0140
TII CKD A 10% 2 0.0140
TII CKD A 10% 3 0.0150
TII CKD A 10% 4 0.0150 average 0.015
TII CKD B 10% 1 0.0110
TII CKD B 10% 2 0.0110
TII CKD B 10% 3 0.0100
TII CKD B 10% 4 0.0120 average 0.011
TII CKD C 10% 1 0.0120
TII CKD C 10% 2 0.0120
TII CKD C 10% 3 0.0110
TII CKD C 10% 4 0.0110 average 0.012
TII CKD D 10% 1 0.0170
TII CKD D 10% 2 0.0170
TII CKD D 10% 3 0.0190
TII CKD D 10% 4 0.0160 average 0.017
TII CKD E 10% 1 0.0210
TII CKD E 10% 2 0.0230
TII CKD E 10% 3 0.0210
TII CKD E 10% 4 0.0220 average 0.022
TII CKD F 10% 1 0.0190
TII CKD F 10% 2 0.0170
TII CKD F 10% 3 0.0180
TII CKD F 10% 4 0.0180 average 0.018
TII CKD LS 20% 1 0.0050
TII CKD LS 20% 2 0.0060
TII CKD LS 20% 3 0.0050
TII CKD LS 20% 4 0.0050 average 0.005
TII CKD SLX 20% 1 0.0050
TII CKD SLX 20% 2 0.0060
TII CKD SLX 20% 3 0.0060
TII CKD SLX 20% 4 0.0060 average 0.006
TII CKD A 20% 1 0.0150
TII CKD A 20% 2 0.0150
TII CKD A 20% 3 0.0140
TII CKD A 20% 4 0.0150 average 0.015
TII CKD B 20% 1 0.0130
TII CKD B 20% 2 0.0130
TII CKD B 20% 3 0.0120
TII CKD B 20% 4 0.0110 average 0.012
TII CKD C 20% 1 0.0140
TII CKD C 20% 2 0.0140
TII CKD C 20% 3 0.0160
TII CKD C 20% 4 0.0150 average 0.015
TII CKD D 20% 1 0.0490
TII CKD D 20% 2 0.0470
TII CKD D 20% 3 0.0490
TII CKD D 20% 4 0.0500 average 0.049
TII CKD E 20% 1 0.0550
TII CKD E 20% 2 0.0530
TII CKD E 20% 3 0.0520
TII CKD E 20% 4 0.0530 average 0.053
TII CKD F 20% 1 0.0280
TII CKD F 20% 2 0.0290
TII CKD F 20% 3 0.0290
TII CKD F 20% 4 0.0290 average 0.029
323
Oneway Analysis of 14d By Cement TII Blends
0
0.01
0.02
0.03
0.04
0.05
0.06
14d
TII
TII C
KD
A 1
0%
TII C
KD
A 2
0%
TII C
KD
B 1
0%
TII C
KD
B 2
0%
TII C
KD
C 1
0%
TII C
KD
C 2
0%
TII C
KD
D 1
0%
TII C
KD
D 2
0%
TII C
KD
E 1
0%
TII C
KD
E 2
0%
TII C
KD
F 1
0%
TII C
KD
F 2
0%
TII C
KD
LS
10%
TII C
KD
LS
20%
TII C
KD
SLX
10%
TII C
KD
SLX
20%
TII Blends
Oneway Anova Summary of Fit Rsquare 0.99626 Adj Rsquare 0.995172 Root Mean Square Error 0.000949 Mean of Response 0.016861 Observations (or Sum Wgts) 72
Analysis of Variance Source DF Sum of Squares Mean Square F Ratio Prob > F TII Blends 16 0.01318511 0.000824 915.6327 <.0001 Error 55 0.00004950 9e-7 C. Total 71 0.01323461
Means for Oneway Anova Level Number Mean Std Error Lower 95% Upper 95% TII 8 0.006500 0.00034 0.00583 0.00717 TII CKD A 10% 4 0.014500 0.00047 0.01355 0.01545 TII CKD A 20% 4 0.014750 0.00047 0.01380 0.01570 TII CKD B 10% 4 0.011000 0.00047 0.01005 0.01195 TII CKD B 20% 4 0.012250 0.00047 0.01130 0.01320 TII CKD C 10% 4 0.011500 0.00047 0.01055 0.01245 TII CKD C 20% 4 0.014750 0.00047 0.01380 0.01570 TII CKD D 10% 4 0.017250 0.00047 0.01630 0.01820 TII CKD D 20% 4 0.048750 0.00047 0.04780 0.04970 TII CKD E 10% 4 0.021750 0.00047 0.02080 0.02270 TII CKD E 20% 4 0.053250 0.00047 0.05230 0.05420 TII CKD F 10% 4 0.018000 0.00047 0.01705 0.01895 TII CKD F 20% 4 0.028750 0.00047 0.02780 0.02970 TII CKD LS 10% 4 0.005500 0.00047 0.00455 0.00645 TII CKD LS 20% 4 0.005250 0.00047 0.00430 0.00620 TII CKD SLX 10% 4 0.007500 0.00047 0.00655 0.00845 TII CKD SLX 20% 4 0.005750 0.00047 0.00480 0.00670 Std Error uses a pooled estimate of error variance