Lab Manual of Concrete Technology

Observation :
Express the amount of water as a percentage by mass of the dry cement to the first place of decimal.
he difference between these two measurements indicates the expansion of the cement. This must not exceed 10 mm for ordinary, rapid hardening and low heat Portland cements. If in case the expansion is more than 10 mm as tested above, the cement is said to be unsound.


Figure

		Distance separating the indicator submerge in normal temp water for 24 hours
Sr. No.					Distances separating the indicator submerge in boiling for three hours.		The difference between these two measurements		Remark
1
2
3
4

Conclusion / R : The given cement is said to be sound / unsound.
Experiment No. : 01(d) Date
Title : Determination of Compressive Strength of Cement
Cement 200 g and Standard Sand 600 g
W
12
ater ^P + 0.3 j percent of combined mass of cement and sand, where P is the percentage of water
required to produce a paste of standard consistency determined as described in IS : 4031 (Part 4)-1988 or Experiment No.1(a).

3. 
   Place on a nonporous plate, a mixture of cement and standard sand. Mix it dry with a trowel for one minute and then with water until the mixture is of uniform colour. The quantity of water to be used shall be as specified in step 2. The time of mixing shall in any event be not less than 3 min and should the time taken to obtain a uniform colour exceed 4 min, the mixture shall be rejected and the operation repeated with a fresh quantity of cement, sand and water.
   
4. 
   Moulding Specimens - In assembling the moulds ready for use, treat the interior faces of the mould with a thin coating of mould oil.
   
5. 
   Place the assembled mould on the table of the vibration machine and hold it firmly in position by means of a suitable clamp. Attach a hopper of suitable size and shape securely at the top of the mould to facilitate filling and this hopper shall not be removed until the completion of the vibration period.
   
6. 
   Immediately after mixing the mortar in accordance with step 1 & 2, place the mortar in the cube mould and prod with the rod. Place the mortar in the hopper of the cube mould and prod again as specified for the first layer and then compact the mortar by vibration.
   
7. 
   The period of vibration shall be two minutes at the specified speed of 12 000 ± 400 vibration per minute.
   
8. 
   At the end of vibration, remove the mould together with the base plate from the machine and finish the top surface of the cube in the mould by smoothing the surface with the blade of a trowel.
   
9. 
   Curing Specimens - keep the filled moulds in moist closet or moist room for 24 ±1 hour after completion of vibration. At the end of that period, remove them from the moulds and immediately submerge in clean fresh water and keep there until taken out just prior to breaking.
   
10. 
    The water in which the cubes are submerged shall be renewed every 7 days and shall be maintained at a temperature of 27 ± 2°C. After they have been taken out and until they are broken, the cubes shall not be allowed to become dry.
    
11. 
    Test three cubes for compressive strength for each period of curing mentioned under the relevant specifications (i.e. 3 days, 7 days, 28 days)
    
12. 
    The cubes shall be tested on their sides without any packing between the cube and the steel plattens of the testing machine. One of the plattens shall be carried on a base and shall be self-adjusting, and the load shall be steadily and uniformly applied, starting from zero at a rate of 35 N/mm¹/min.
    

Figure





Observation

Sr. No.	Age of Cube	Weight of Cement Cube ^(g^ms)	Cross­Sectional area (mm^2)	Load (N)	Compressive strength (N/mm^2)	Average Compressive strength (MPa)
1	7 Days
2
3
4	28 Days
5			'
6

Calculation :
The measured compressive strength of the cubes shall be calculated by dividing the maximum load applied to the cubes during the test by the cross-sectional area, calculated from the mean dimensions of the section and shall be expressed to the nearest 0.5 N/mm². In determining the compressive strength, do not consider specimens that are manifestly faulty, or that give strengths differing by more than 10 percent from the average value of all the test specimens.
Conclusion / Result :

1. 
   The average 3 Days Compressive Strength of given cement sample is found to be
   
2. 
   The average 7 Days Compressive Strength of given cement sample is found to be
   
3. 
   The average 28 Days Compressive Strength of given cement sample is found to be
   

SI. No. Type of	Fineness	Soundness By			Setting Time		Compressive Strength
Cement	(rtf/kg) Min.	Lc chatclier (mm) Max.	Ли toe lave (%) Max.	Initial (mts) min.		Final (mts) max.	7 Day min. MPa	3 Days min. MPa	7 Days min. MPa	28 Days min. MPa
1. 33 Grade OPC (IS 269-1989)	225	10	0.8	30		600	N S	16	22	33
2. 43 Grade OPC (IS 8112-1989)	225	10	0.8	30		600	N S	23	33	43
3. 53 Grade OPC (IS 12269-1987)	225	10	0.8	30		600	N S	27	37	53
4. SRC (IS 12330-1988)	225	10	0.8	30		600	N S	10	16	33
5. PPC (IS 1489-1991) Part I	300	10	0.8	30		600	N S	16	22	33
6. Rapid Hardening (IS 8041-1990)	325	10	0.8	30		600	16	27	N S	N S
7. Slag Cement (IS 445-1989)	225	10	0.8	30		600	N S	16	22	33
8. High Alumina Cement (IS 6452-1989)	225	5	N S	30		600	30	35	N S	N S
9. Super Sulphated Cement (IS 6909-1990)	400	5	N S	30		600	N S	15	22	30
10. Low Heat Cement (IS 12600 1989)	320	10	0.8	60		600	N S	10	16	35
11. Masonry Cement (IS 3466-1988)	*	10	1	90		1440	N S	N S	2.5	5
12. IRS-T-40	370	5	0.8	60		600	N S	N S	37.5	N S

Experiment No.	: 02(a)	Date
Title	: Particle Size Distribution of Fine Aggregates

Objective : To determine fineness modulus of fine aggregate and classifications based on
IS: 383-1970
Reference : IS : 2386 ( Part I) - 1963, IS: 383-1970, IS : 460-1962
Theory :
This is the name given to the operation of dividing a sample of aggregate into various fractions each consisting of particles of the same size. The sieve analysis is conducted to determine the particle size distribution in a sample of aggregate, which we call gradation. Many a time, fine aggregates are designated as coarse sand, medium sand and fine sand. These classifications do not give any precise meaning. What the supplier terms as fine sand may be really medium or even coarse sand. To avoid this ambiguity fineness modulus could be used as a yard stick to indicate the fineness of sand.
The following limits may be taken as guidance: Fine sand : Fineness Modulus : 2.2 - 2.6, Medium sand : F.M. : 2.6 - 2.9, Coarse sand : F.M. : 2.9 - 3.2
Sand having a fineness modulus more than 3.2 will be unsuitable for making satisfactory concrete.

15
Apparatus :
Test Sieves conforming to IS : 460-1962 Specification of 4.75 mm, 2.36 mm, 1.18 mm, 600 micron, 300
micron, 150 micron, Balance, Gauging Trowel, Stop Watch, etc.
Procedure :

1. 
   The sample shall be brought to an air-dry condition before weighing and sieving. The air-dry sample shall be weighed and sieved successively on the appropriate sieves starting with the largest. Care shall be taken to ensure that the sieves are clean before use.
   
2. 
   The shaking shall be done with a varied motion, backward sand forwards, left to right, circular clockwise and anti-clockwise, and with frequent jarring, so that the material is kept moving over the sieve surface in frequently changing directions.
   
3. 
   Material shall not be forced through the sieve by hand pressure. Lumps of fine material, if present, may be broken by gentle pressure with fingers against the side of the sieve.
   
4. 
   Light brushing with a fine camel hair brush may be used on the 150-micron and 75-micron IS Sieves to prevent aggregation of powder and blinding of apertures.
   
5. 
   On completion of sieving, the material retained on each sieve, together with any material cleaned from the mesh, shall be weighed.
   

Observation :

I S Sieve	Weight Retained on Sieve (gms)	Percentage of Weight Retained (%)	Percentage of Weight Passing (%)	Cumulative Percentage of Passing (%)	Remark
4.75 mm
2.36 mm
1.18 mm
600 micron
300 micron
150 micron
Total

Calculation :
Fineness modulus is an empirical factor obtained by adding the cumulative percentages of aggregate retained on each of the standard sieves ranging from 4.75 mm to 150 micron and dividing this sum by an
T
arbitrary number 100.

16

Finess Modulus, FM =
otal of Cumulative Percentage of Passing (%) 100
Conclusion / Result :

1. 
   Fineness modulus of a given sample of fine aggregate is that indicate Coarse sand/ Medium sand/
   

Fine sand.

2. 
   The given sample of fine aggregate is belong to Grading Zones I / II / III / IV
   

Table 3.15. Grading limits of fine aggregates IS: 383-1970

f.S. Sieve Designation		Percentage passing by weight for
	Grading Zone 1	Grading Zone H	Grading Zone Hi	Grading Zone /V
7 0 mm	700	700	700	700
4.75 mm	90-7 00	90-700	90-700	95-7 00
2.36 mm	60-95	75-7 00	35-700	95-7 00
7.78 mm	30-70	55-90	75-700	90-7 00
600 micron	7 5-34	35-59	60-79	30-7 00
300 micron	5-20	8-30	72-40	7 5-50
7 50 micron	0-70	0-7 0	0-70	0-7 5

Experiment No.	: 02(b)	Date
Title	: Determination of Bulking of Fine Aggregate

Objective


To determine bulking of a given sample of fine aggregate.

I

Reference
S : 2386 ( Part III ) - 1963
Theory :
Free moisture forms a film around each particle. This film of moisture exerts what is known as surface tension which keeps the neighbouring particles away from it. Similarly, the force exerted by surface tension keeps every particle away from each other. Therefore, no point contact is possible between the particles. This causes bulking of the volume. It is interesting to note that the bulking increases with the increase in moisture content upto a certain limit and beyond that the further increase in the moisture content results in the decrease in the volume and at a moisture content representing saturation point, the
:
Per cent of moisture added by weight to dry, rodded fine aggregate

10

о jg и eO
a §>

30

40

		Fine gradin	В
		ledii^K rading
	—. ^Coa ^\grad	rse \ ^ing N.

fine aggregate shows no bulking.

17

Apparatus
Measuring jar, Taping rod etc.
Procedure :

1. 
   Put sufficient quantity of the sand loosely into a container. Level off the top of the sand and pushing a steel rule vertically down through the sand at the middle to the bottom, measure the height. Suppose this is h1 cm.
   
2. 
   Empty the sand out of the container into another container where none of it will be lost. Half fill the first container with water. Put back about half the sand and rod it with a steel rod, about 6 mm in diameter, so that its volume is reduced to a minimum. Then add the remainder of the sand and rod it in the same way.
   
3. 
   The percentage of bulking of the sand due to moisture shall be calculated from the formula:
   

P
Г j Л — -1 —1

x100
ercentage Bulking =

B
Conclusion / Result

%
ulking of a given sample of fine aggregate is found to be

Experiment No.	: 02(c)	Date
Title	: Determination of Silt Content in Fine Aggregate

Objective



R
To determine silt content in a given sample of fine aggregate by sedimentation method.
IS : 2386 ( Part II ) - 1963
eference

Lab Manual of Concrete Technology 1
Sanjay Ghodawat Group of Institutions 1
Introduction : 2
Course Objectives 2
Student Responsibilities 2
Report Writing 3
Laboratory Regulations 3
Experiment No. : 01(a) Date 4
Title : Determination of Consistency of Standard Cement Paste 4
Theory : 4
Apparatus : 4
Procedure : 4
Experiment No. : 01(b) Date 6
Title : Determination of Setting Time of Standard Cement Paste 6
Theory : 6
Apparatus : 6
Procedure : 6
Experiment No. : 01(c) Date 9
Title : Determination of Fineness of Cement by dry sieving 9
Theory : 9
Procedure : 9
Theory : 10
Apparatus : 10
Experiment No. : 01(d) Date 12
Title : Determination of Compressive Strength of Cement 12
Theory : 15
15 15

1The material for each cube shall be mixed separately and the quantity of cement, standard sand and water shall be as follows: