CONCRETE LABORATARY MANUAL - Madin Poly LAB MANUAL-404.pdf · CONCRETE LABORATARY MANUAL CIVIL ENGINEERING SUB: ... Specific gravity of substance=wt density of a substance/wt density
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______________________________________________________
CONTENTS
___________________________________________________________________
S.NO . TITLE PG.NO _________________________________________________________________
1. FINENESS TEST ON CEMENT
2. BULKING OF SAND.
3. TEST ON AGGREGATE FOR CONCRETE-SIEVE ANALYSIS
4. SPECIFICGRAVITY OF CEMENT
5. PROPERTIES OF FRESH CONCRETE-WORKABBILITY.A.SLUMP TEST
6.CONSISTENCY TEST ON CEMENT
7.COMPERSSIVE STRENGTHON CONCRETE CUBES ________________________________________________________________
Instructions.1.
Write observations, tables, diagrams, Specimen calculations
in the blank left side of the journal and others to the right.
FINENESS TEST ON CEMENT
Experiment No.1
DATE : _________________________________________________________________
Aim
To determine the fineness of agiven sample of cement
Theory
Strength development of concrete is the result of the reactions of
water with cement particles.The reactions always start with the cement
available at the surface of the particles.Thus larger the surface area
available for reaction greater the rate of hydtration.Rapid development
of strength requires grater degree fineness.however too much fineness
is alsoconsiderable.finer cement deteriorates more quickly when
exposed to air and and is likely to cause more shrinkage,but less prone
to bleeding
Apparatus
1)Weighing balance
2)Is test sieve 90 micron
3)Brush and handle
4)Tray and trowel
Procedure
1)weigh accurately 100g of cement and place it on astandared Is sieve
90 micron
2)Breakdown any air set lumps in the sample with fingers but donot run
on the sieve.
3)Continuosly sieve the sample by holding the sieve in both hands and
giving a gentle wrist motion or mechanical sieve shaker may be uesed
fo r this purpose
4)Weigh the residue left after 15 minutessieving this residue shall not
exeed the specified limits
Result
Fineness of cement=10%
Discussion
For ordinary portland cement fineness shouldnot be more than
10% of orginal weight.
BULKING OF SAND
Experiment No.2
DATE : _________________________________________________________________
Aim
To determine the moisture content at which bulking of sand
occurs
Apparatus
Measuring jar,weighing balance,mixing pan,trowel….etc
Principle
Percentage of bulking of sand=V-Va/Va X100
V=Volume of bulked sand Va=Actual volume of sand
Procedure
1)Take200 ml of sand in measuring jar and take the weight of sand
2)Add water is one percentage of the weight(sand) and mixed
thoroughly and measure the increasing volume
3)Add 2%,3%,4%..........and theproces is repeated for number of times
and each increase in volume is taken
4)After the increase in volume there is a slow decreasein volume ,then
pure water is added to the sand to increase it.That will give orginal
volume
5)When water added the volume ofsand increased and an optimum
volume of sand reached
6)A graph is ploted by taking percentage of increase in volume
and percentage of bulking
Observations:
% of
moisture
Volume of
water(ml)
Volume of
bulked sand
% of bulking
Result:
The maximum bulking of sand takes place at moisture content is
………%
Water content at which maximum bulking occure…..%
Inference:
Bulking of sand increases with increase in moisture content up to
a certain limit beyond that further increase in moisture content
decrease the volume of bulked sand.
TEST ON AGGREGATES FOR CONCRETE – PARTICLE SIZE
DISTRIBUTION
SIEVE ANALYSIS Experiment No.3
Date :
________________________________________________________________
Aim:
To determine the particle size distribution of fine aggregate by conducting dry sieve
analysis. Also identify to which zone, the given sample of aggregate belong.
Theory:
The aggregate most of which passes IS 475mm sieve is classified as fine aggregate
and retained on 4.75mm sieve is classified as coarse aggregate can be obtained. A
sample may be well graded, poorly graded or uniformly graded. The term D10 or
effective size represents sieve opening such that 10% of the particle are finer than this
size. Similarly D30 and D60 can also be obtained from the graph. Then, uniformity
coefficient
Cu = D60/D10
Fitness Modulus is a term indicating the coarseness or fitness of the material. It is
obtained by adding the cumulative property percentages of aggregate retained on each
of the sieve and dividing them by 100
Apparatus:
• Balance
• Sieves- sieve of the size given in table 1 conforming to IS: 460-1962
specifications for tests series shall be used.
• Sample- the weight of sample available shall not be less than the weight given in
Table 2
Table 1
I.S SIEVES FOR ANALYSIS OF AGGREGRATES FOR CONCRETE
Type Sieve designation
Square hole, Perforated plate 80mm,63mm,50mm,40mm,31.5mm,25mm, 20mm,16mm,12.5mm,10mm,6.3mm,4.75mm
Fine mesh, Wire cloth 3.35mm,2.36mm,1.18mm, 600micron,300micron,150micron,75micron
Observations & Calculations
I.S Sieve size Percentage passing by weight for
Grading zone 1 Grading zone2 Grading zone3 Grading zone4
10mm 100 100 100 100
4.75mm 90-100 90-100 90-100 95-100
2.36mm 60-95 75-100 85-100 95-100
1.18mm 30-70 55-90 75-100 90-100
600micron 15-34 35-59 60-79 80-100
300micron 5-20 8-30 12-40 15-50
150micron 0-10 0-10 0-10 0-15
Fitness modulus
4.0-2.41 3.37-2.10 2.78-1.71 2.25-1.35
Sample:_________________________________________
Sieve
Size
mm
Col 1
Col 2
Col 3
Col 4
Col 5
Sieve
Tare
grams
Mass of
Sieve and
Aggregate
grams
Mass
Retained
(Col 2 -
Col 1)
grams
Cumulative
Mass
Retained
( of
consecutive
rows in Col
3)
grams
Cumulative
Percent
Retained
(Col 4 / A *
100)
%
Cumulative
Percent
Passing
(100 - Col
5)
%
37.5
25
19
12.5
9.5
4.75
2.36
1.18
0.6
0.3
0.15
0.075
Minus
0.075
(Pan +
C)
TOTAL
Fineness modulus (F.M) = ∑ (Cumulative % retained)/100
Table 2
MINIMUM WEIGHT OF SAMPLE FOR SIEVE ANALYSIS
Maximum size present in substantial proportions(mm)
Minimum weight of sample to be taken for sieving (kg)
63 50
50 35
40or31.5 15
25 5
20or16 2
12.5 1
10 0.5
6.3 0.2
4.75 0.2
2.36 0.1
Procedure
• The sample is brought to an air- dry condition before weighing and sieving either
by drying at room temperature or by heating at a temperature of 100 ̊ to 110 c
• The dried sample is weighed.
• The weighed sample is placed on the sieve and sieved successively on the
appropriate sieves starting with the largest.
• Each sieve is shaken separately over a clean tray until not more than a trace
passes, but in any case for a period of not less than 2 minutes. The Shaking is
done with a varied motion, backward and anti clockwise. Lumps of fine materials
if present may be broken by gentle pressure with fingers against the side of the
sieve.
• At the end of sieving, 150 microns and 75 micron sieves are cleaned from the
bottom by light brushing with fine hair brush.
• On completion of sieving, the material retained on each sieve together with any
material cleaned from mesh, is weighed.
• This procedure is done for both coarse and fine aggregates.
• A curve is drawn between percentage passing and the sieve size for fine
aggregate.
Result :
Fine aggregates Result
Effective size D10 = micron
Uniformity coefficient=
Fineness modulus =
Zone =
Discussion:
SPECIFIC GRAVITY OF CEMENT
Experiment No.4 Date : _______________________________________________________________
Aim:
To determine the specific gravity of cement
TheOry:
The specific gravity of cement is the ratio of the weight of a given
volume of substance to the weight of an equal volume of water.It is a
mere number and it denotes howmany times a substance is heavy as
water
Specific gravity of substance=wt density of a substance/wt density of
water
To find the specific gravity of cement,it is requeirred to find the weight
of a certain volume cement and the weight of an equal volume of
water.As cement reacts with water its specific gravity is determined
with reference to a non reactive liquid like kerosene
Specific gravity of cement w,r.to kerosine=wt of cement/wt of an equal
volume of kerosene
To find the specific gravity of kerosene w.r.t water=wt of kerosene/wt of
equal volume of water
The specificgravity of cement is the calculation by multiplying specific
gravity of cement w.r.to kerosene with specific gravity of kerosene w.r.t
water
Procedure:
1)Clean dry and wegh specific gravity bottle
2)Take certain quantity of cement (about one fourth of the bottle)in the
bottle and weigh(w2)
3)Pour kerosene over the cement to fill the bottle and find the total
weight(w3)
4)Clean the bottle thoroghly with kerosene and fill the bottle with
kerosene and weigh (w4)
5)Finally clean the bottle with water and weigh(w5)
Tabulation:
Weight of bottle(w1)=
Weight of bottle+cement(w2)=
Weight of bottle+cement+kerosene(w3)=
Weight of bottle+kerosene filling bottle(w4)=
Weight of bottle+water filling bottle(w5)=
Calculation:
Weight of cement w.r to kerosene(wc)=w2-w1
Weight of an equal volume of kerosene(wk)=(w4-w1)-(w3-w2)
Specific gravity of cement w rto kerosene(csk)=Wc/Wk
Weight of kerosene filling bottle (Wk)=w4-w1
Weight of an equal volume of water(mw)=w5-w1
specific gravity of kerosene wr to water(ksw)=Wk/mw
There for specific gravity ofcement wr to water=csk X ksw
Result:
Specific gravity of cement w.r.to water=
As per Is specification specific gravity of cement in between 2.4-
2.8
Discussion:
PROPERTIES OF FRESH CONCRETE – WORKABILITY
• Slump Test
Experiment No. 5
Date :
_____________________________________________________________________
Aim: To determine the slump test of the prepared mix and study it’s characteristics
Theory:
Unsupported fresh concrete flows to the sides and a sinking in height takes place. This vertical settlement is known as slump. In this test fresh concrete is filled into a mould of specified shape and dimensions, and the settlement or slump is measured when
supporting mould is removed. Slump increases as water-content is increased. For different works different slump
values have been recommended. The slump is a measure indicating the consistency or workability of cement concrete. It gives an idea of water content needed for concrete to be used for different works. A concrete is
said to be workable if it can be easily mixed, placed, compacted and finished. A workable concrete should not shown any segregation or bleeding. Segregation is said to occur when coarse aggregate tries to separate out from the finer material and a concentration of coarse aggregate at one place occurs. This results in large voids, less durability and strength. Bleeding
of concrete is said to occur when excess water comes up at the surface of concrete. This causes small pores through the mass of concrete and is undesirable. By this test we can determine the water content to give specified slump value. In this test water content is varied and in each case slump value is measured till we arrive at water content giving the required slump value. This test is not a true guide to workability. For example, a harsh mix cannot be said to
have same workability as one with a large proportion of sand even though they may have the
same slump.
Apparatus
Iron pan to mix concrete, slump cone, spatula, trowels, tamping rod and graduated cylinder.
Slump test apparatus
Procedure
Four mixes are to be prepared with water-cement ratio (by mass) of 0.50, 0.60, 0.70 and
0.80, respectively, and for each mix take 10 kg of coarse aggregates, 5kg of sand and 2.5kg of cement with each mix proceed as follows
1) Mix the dry constituents thoroughly to get a uniform colour and then add water 2)
Place the mixed concrete in the cleaned slump cone mould in 4 layers, each
approximately ¼ of the height of the mould. Tamp each layer 25 times with tamping rod distributing the strokes in a uniform manner over the cross-section of the mould. For the second and subsequent layers the tamping rod should penetrate in to the underlying layer. 3) Strike off the top with a trowel or tamping rod so that the mould is exactly filled. 4) Remove the cone immediately, raising it slowly and carefully in the vertical direction. 5) As soon as the concrete settlement comes to a stop, measure the subsidence of
concrete in mm which will give the slump. Note: Slump test is adopted in the laboratory or during the progress of work in the field for determining consistency of concrete where nominal maximum size of aggregate does not exceed 40mm
Any slump specimen which collapses or shears off laterally gives incorrect results and if this occurs the test is repeated, only the true slump should be measured.
Observations & Calculations
CONSISTENCY TEST ON CEMENT
Experiment No.6
DATE : _____________________________________________________________________
Aim
To determine the percentage of water for normal consistency
Theory
For findingout initial setting time ,final stting time and soundness
of cement a standared parameter known as standared consistency has
to beused
Since defferent batches of cement deffer in fineness,pastes with
some water content may deffer in consistency when first mixed.For this
reason the consistency of the paste is standardized by varying the
water content untill the paste has a given resistance to penetration.
Standared or normal consistency of a cement paste is defined as
that consistency(degree of wetness) which will permit the vicat plunger
to penetrate the cement paste to a point 5-7mm from the vicat mould
when the cement paste is tested within 3-5 minutes after it is mixed
with water.
Apparatus
1)Vicats apparatus with a 10mm diameter plunger and a needle of
1mm square section
2)Vicat mould
3)Non porous pate
4)Measuring jar
5)Trowel
Vicats apparatus
Procedure
1)The mould and the non porous plate are washed,cleaned and dried
2) 400g of the given sample of cement is kept on the non porous plate
3) 30% water by weight of cement is added very care fully to dry
cement and mixed thoroughly to get a neat cement paste.care should
be taken that the time of gauging is not lessthan 3 minutesand and not
morethan 5minutes.the gauging time shall be counted from he time of
adding water to the dry cement until commencing to fil the mould
4)The vicat mould is placed on the non porous plate and is filled with
the prepared cement paste with trowel,the surface is smoothened is
level with the mould
5)By shaking mould slightly any air from the sample is expelled
6)The non porous plate and mould are placed under the plunger
7)The plunger is gently leveled to touch the surface of paste and then
the indicator is adjusted to show zero reading
8)The plunger is released quickly and allowed to penitrate in to the
paste
9)When the plunger comes to rest,the reading on the index scale is
noted
10)Several trial pastes are prepared with varying percentages of water
and the test is conducted untill the needle penetrated 5mm-7mm
above the bottom of the mould
Observations:
Si
no
Wt of cement
taken(g)
Volumeof water
added
Water added
as % of by
weight of dry
cement
Penetration
index reading
Result
Found standared or normal consistency of cement=
Discussion
The usual range of values being between26 and 33%
COMPRESSIVE STRENGTH OF CEMENT CONCRETE Exp No: 7
Date:
_____________________________________________________________________
Aim: To determine the cube strength of the concrete of given properties
Apparatus required: Moulds for the test cubes, tamping rods
Procedure.
1. Calculate the material required for preparing the concrete of given proportions
2. Mix them thoroughly in mechanical mixer until uniform colour of concrete is
obtained
3. Pour concrete in the oiled with a medium viscosity oil. Fill concrete is cube
moulds in two layers each of approximately 75mm and ramming each layer with
35 blows evenly distributed over the surface of layer.
4. Fill the moulds in 2 layers each of approximately 50mm deep and ramming each
layer heavily.
5. Struck off concrete flush with the top of the moulds.
6. Immediately after being made, they should be covered with wet mats.
7. Specimens are removed from the moulds after 24hrs and cured in water 28 days
8. After 24hrs of casting, cylinder specimens are capped by neat cement paste 35
percent water content on capping apparatus. After 24 hours the specimens are
immersed into water for final curing.
9. Compression tests of cube and cylinder specimens are made as soon as
practicable after removal from curing pit. Test-specimen during the period of their
removal from the curing pit and till testing, are kept moist by a wet blanket
covering and tested in a moist condition.
10. Place the specimen centrally on the location marks of the compression testing
machine and load is applied continuously, uniformly and without shock.
11. Also note the type of failure and appearance cracks.
Observations:
Specimen Trials Mean Value N/mm2
1 2 3
Load on cubes, KN
Result:
The compressive strength of cementconcreteis________________N/mm2
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