Mark B. Snyder, Ph.D., P.E., Engineering Consultant Bridgeville, Pennsylvania Prepared for presentation at the 2008 Minnesota Concrete Conference Continuing Education and Conference Center, St. Paul, MN February 14, 2008
Mark B. Snyder, Ph.D., P.E., Engineering ConsultantBridgeville, Pennsylvania
Prepared for presentation at the 2008 Minnesota Concrete ConferenceContinuing Education and Conference Center, St. Paul, MN February 14, 2008
FHWA-Sponsored Research
University of MinnesotaERES Consultants, Inc.
Physical and Mechanical PropertiesPhysical and Mechanical Propertiesf Recycled PCC Aggregate Concretf Recycled PCC Aggregate Concret
1993 1993 -- 19991999
RCA has been used widely with varying results.Most common failures:◦deteriorated midpanel cracks◦ loss of load transfer
Determine causes of pavement distress related to use of RCA in PCC pavements.Develop practical, reliable guidelines for RCA concrete mix designs.Identify pavement designs for which RCA concrete is appropriate.
Extensive Literature ReviewField Testing and EvaluationLaboratory Testing and Evaluation
Distress (cracked, uncracked, other)JRCP, JPCP (CRCP?)Available control sectionRange of climates, trafficUniform traffic flowNo substructures
Original 1993 Study:9 Projects
5 RCA + Control 4 RCA Only
2 Single Sections1 Varying LT1 Varying Performance
16 Sections Total
Category Location Climatic Region
1994 Age, Yrs
Control Section
2 Way ADT, veh/day
Pavement Type (% long.
reinf.)
Joint Spacing, ft
Dowel Diam., in
1(Good)
CT 1, I-84 near Hartford
W-F 14 yes 56,000 9-in JRCP(0.10 %)
40 1.5 (I-beam)
MN 1, I-94 near Brandon
W-FTransition
6 yes 8,170 11-in JRCP(0.06 %)
27 1.25
KS 1, K-7Johnson County
W-F 9 yes 7,310 9-in JPCP(n/a)
15 None
2(Structural Problems)
MN 4, US52near Zumbrota
W-F 10 yes 7,820 9-in JRCP(0.06 %)
27 1.0
MN 2, I-90 Beaver Creek
W-FTransition
10 no 1,670 9-in JRCP(0.06 %)
27 1.0
WI 1, I-94 near Menomonie
W-F 10 no 8,170 11-in JPCP(n/a)
12-13-19-18 None / 1.375
3(Other
Distresses)
MN 3, US59 near Worthington
W-FTransition
14 no 2,150 8-in JPCP(n/a)
13-16-14-19 None
WI 2, I-90 near Beloit
W-F 8 no 22,622 10-in CRCP(0.67 %)
n/a n/a
WY 1, I-80 near Pine Bluffs
D-F 9 / 10 yes 4,410 (RCA)4,280 (Con.)
10-in JPCP(n/a)
14-16-13-12 None
Condition SurveyDrainage SurveyFWDCoring◦ Midpanel◦ Joints◦ Cracks
Crack, Joint WidthFaultingPSRPhotolog
CompressionSplit TensionStatic EDynamic E
• α
Surface Texture◦Sand Patch◦ProfilometerFreeze-ThawLinear TraversePetrography
FHWA-Sponsored Research
University of New HampshireRecycled Materials Resource Center
Performance of Concrete PavementsPerformance of Concrete PavementsContaining Recycled Concrete Containing Recycled Concrete
AggregateAggregate20062006
(Update of previous study)(Update of previous study)
Revisit 1994 study sections to obtain longer-term materials and performance data.Include additional test sites to expand inference base of original study.Update conclusions from 1994 study.
Category Location Climatic Region
2006 Age, Yrs
Control Section
2 Way ADT, veh/day
Pavement Type (% long.
reinf.)
Joint Spacing, ft
Dowel Diam., in
3(Other
Distresses)
IA 1, US 75 near Rock
Rapids
W-F 30 no 2,150 9-in JPCP(n/a)
13-16-14-19 None
IL 1, I-57 near Effingham
W-F 20 no 4,410 (RCA)4,280 (Con.)
10-in CRCP(n/a)
n/a n/a
Condition SurveyDrainage SurveyCoring◦ Midpanel◦ Joints◦ Cracks
[No FWD]
Crack, Joint WidthFaultingPSRPhotolog
CompressionSplit TensionStatic E
Modified ASTM C 1293 (ASR)ASTM C 856 (Uranyl Acetate)Volumeteric Surface TexturePetrography
Project Review and Performance Summary(Age 18 yrs)
Recycled
Recycled
Recycled
Control
Control
Control
MN 1-1 (Recycled) MN 1-2 (Control)Sturtevant M.S. Thesis - 2007
Test and ValueMN 1-1
(Recycled)MN 1-2
(Control)
Transverse Joint Spalling,% Joints
76 54
Avg. Faulting between Panels, mm 0.9 1.3
Longitudinal Cracking, m/km 0 0
Transverse Cracking, % Slabs 31 0
Deteriorated TransverseCracks/km
35 0
Total Transverse Cracks/km 38 0
PSR 3.7 4.0
IRI 1.1 0.9
Tensile Strength, MPa 2.9 3.3
Compressive Strength, MPa 44.9 59.0
Uranyal Acetate Reaction None None
Young’s Modulus, GPa 28.9 33.4
•Comparable performances in 1994•Mortar Content
•77% RCA•66% Control
•Similar Thermal Coefficients in 1994•11.9/Co RCA•11.9/Co Control
•~25% increase in Young’s modulus since 1994•Inconsistent strength trends since 1994•RCA strength consistently lower, but adequate
Project Review and Performance Summary(Age 22 yrs)
I-90 EB
I-90 EB
I-90 EB
I-90 WB
I-90 WB
I-90 WB
MN 2-1 (Recycled) MN 2-2 (Recycled)Sturtevant M.S. Thesis - 2007
Test and ValueMN 2-1(RCA 1)
MN 2-2(RCA 2)
Transverse Joint Spalling,% Joints
46 66
Avg. Faulting between Panels, mm 0.6 0.5Avg. Joint Width, mm 12 13Longitudinal Cracking, m/km 26 0Transverse Cracking, % Slabs 90 92Deteriorated TransverseCracks/km
112 112
Total Transverse Cracks/km 112 115PSR 4.0 3.8IRI 0.9 1.0Tensile Strength, MPa 3.7 2.8Compressive Strength, MPa 49.5 64.1Uranyal Acetate Reaction Low NoneModified ASTM 1293, % Expansion at 108 Days
0.054 n/a
Young’s Modulus, GPa n/a 31.1
Project Summary and Performance Review(Age 26 yrs)
MN
MN
MN
MN
MN 3-1 (Recycled)Sturtevant M.S. Thesis - 2007
Test and ValueMN 3(1994)
MN 3(2006)
Transverse Joint Spalling,% Joints
71 89
Transverse Joint Seal Damage,% Joints
76 0
D-cracking, % Slabs 0 0Avg. Faulting between Panels, mm 6.1 0.3Avg. Joint Width, mm 20 18Longitudinal Cracking, m/km 19 0Transverse Cracking, % Slabs 2 12Deteriorated TransverseCracks/km
3 26
Total Transverse Cracks/km 3 26PSR 3.0 4.3IRI 1.7 0.6Tensile Strength, MPa 4.1 3.7Compressive Strength, MPa 44.1 52.4
42
Recycled section only
Constructed in 1980
Rehabilitated after 1994
Diamond grinding
Retrofitting of transverse dowel bars
PSR = 4.3 (3.0 in 1994)
Avg. faulting between panels = 0.3 mm (6.1 mm in 1994)
No recurring D-cracking
ASR found during uranyl acetate testing
Moderate expansion in Modified ASTM 1293 testing
No ASR related distress found in field
Project Summary and Performance Review(Age – 22 yrs)
MN 4-1 (Recycled) MN 4-2 (Control)Sturtevant M.S. Thesis - 2007
Test and ValueMN 4-1
(Recycled)MN 4-2
(Control)Transverse Joint Spalling,% Joints
81 100
D-cracking, % Slabs 0 0Pumping, % Slabs 0 0Slab/Patch Deterioration,% Slabs
3 0
Avg. Faulting between Panels, mm 0.9 0.9
Avg. Joint Width, mm 12 11Longitudinal Cracking, m/km 17 0Transverse Cracking, % Slabs 92 24Deteriorated TransverseCracks/km
125 26
Total Transverse Cracks/km 131 29PSR 3.0 3.8IRI 1.7 1.0Tensile Strength, MPa 2.4 2.5Compressive Strength, MPa 45.1 50.7Uranyal Acetate Reaction None NoneYoung’s Modulus, GPa 30.0 43.4Average VSTR (cm3/cm2) 0.2902 0.3264
•In 1994, performances were comparable, but RCA section was showing signs of imminent deterioration•Foundation Stiffness (backcalculated) 30% lower for RCA section•Aggregate Top Size
•1.0-in RCA•1.5-in Control
•Mortar Content•84% RCA (higher shrinkage?)•52% Control
•Similar Thermal Coefficients in 1994•12.4/Co RCA•11.9/Co Control
•~10% increase in compressive strength since 1994
47
Recycled and control sections rehabilitated after 1994
Diamond grinding
Retrofitting of transverse dowel bars
Field survey showed recycled did not perform as well as control
Recycled had higher mortar content (74% vs. 52%)
Formation of shrinkage cracks early on
Figure 58: Recycled Pavement Distresses (Avg. % Change from 1994 to 2006)
-40%
-20%
0%
20%
40%
60%
80%
100%
T. J
. Spa
lling
T. J
.Sea
l Dam
age
L. J
. Sea
l D
amag
e
D-c
rack
ing
Pum
ping
Slab
/Pat
chD
eter
iora
tion
L. to
S. D
rop
off
L. to
S. S
epar
atio
n
Faul
ting
Join
t Wid
th
L. C
rack
ing
T. C
rack
ing
Det
erio
rate
d T.
Cra
cks
Tota
l T. C
rack
s
PSR IR
I
% C
hang
e (9
4 to
06)
AllRehabilitedNot Rehabilitated
Sturtevant M.S. Thesis - 2007
Figure 59: Control Pavement Distresses (Avg. % Change from 1994 to 2006)
-40%
-20%
0%
20%
40%
60%
80%
100%
T. J
. Spa
lling
T. J
.Sea
l Dam
age
L. J
. Sea
l D
amag
e
D-c
rack
ing
Pum
ping
Slab
/Pat
chD
eter
iora
tion
L. to
S. D
rop
off
L. to
S. S
epar
atio
n
Faul
ting
Join
t Wid
th
L. C
rack
ing
T. C
rack
ing
Det
erio
rate
d T.
Cra
cks
Tota
l T. C
rack
s
PSR IR
I
% C
hang
e (9
4 to
06)
AllRehabilitedNot Rehabilitated
Sturtevant M.S. Thesis - 2007
•Need to treat RCA as “engineered material” and modify mix and structural designs accordingly
•Reduce w/c•ASR mitigation•Reduced panel lengths•Etc.
•Mortar contents generally higher for RCA•Reclaimed mortar content varied with virgin aggregate type, crushing process•RCA, conventional aggregate PCC performance comparable when natural CA types and quantities are similar•Higher mortar contents had more distress – need to control reclaimed mortar content
Granular Base Sections◦ CT1-1, 16.6, 66%◦ CT1-2, 15.2, 93%◦ MN1-1, 7.3, 1%◦ MN1-2, 7.3, 0%◦ MN2-1, 8.2, 84%◦ MN4-1, 7.8, 88%◦ MN4-2, 8.2, 22%
◦ WI1-1, 4.4, 8%◦ WI1-2, 4.6, 2%◦ WY1-1, 4.3, 0%◦ WY1-2, 4.3, 0%
Stabilized Base Sections◦ KS1-1, 5.5, 0%◦ KS1-2, 5.5, 0%◦ MN3-1, 5.0, 2%
•Use of RCA has no apparent direct influence on joint faulting (dowels, aggregate size, structural design parameters are more important)•Recycled ASR concrete used successfully in Wyoming with mitigation measures
•Isolated recurrent ASR•RCA performed better than control
•Recycled D-cracked concrete used successfully with mitigation measures
•Reduced aggregate size•Reduced moisture exposure?
Federal Highway AdministrationMinnesota Department of TransportationJeff Sturtevant, Prof. David Gress and the University of New Hampshire Recycled Materials Resource Center (RMRC)Greg Cuttell, Julie Vandenbossche and many other former U-M Grad and Undergrad Research AssistantsApplied Research Associates, Inc. (formerly ERES Consultants)
Thank You!
Any Questions?