Fineness Test (concrete)

7/31/2019 Fineness Test (concrete)

1/9

0 | P a g e

CONTENT

NO TITLE PAGE

1 THEORY 1

2 APPARATUS 1

3 MATERIAL 2

4 PROCEDURES 2

5 RESULT 3

6 DISCUSSION 47 CONCLUSION 5

8 QUESTIONS 6

9 APPENDIX 7

10 REFERENCE 8


2/9

1 | P a g e

EXPERIMENT : 1

TITLE 1 : FINENESS TEST

OBJECTIVE : To determine the fineness of cement by dry sieving.

THEORY

So we need to determine the fineness of cement by dry sieving as per IS: 4031 (Part 1)

1996. The principle of this is that we determine the proportion of cement whose grain size is

large the specified mesh size. The fineness of cement influences the drying shrinkage of

concrete. When the water content is increased because of fineness, the drying shrinkage is

increased. However, if excessive bleeding due to coarseness of the cement takes place, a

reduction in the drying shrinkage occurs.

APPARATUS

1. 90 m IS Sieve,

2. Balance capable of weighing 10g to the nearest 10mg

3. A nylon or pure bristle brush, preferably with 25 to 40mm.

4. Bristle, for cleaning the sieve.

5. Sieve shown in picture below is not the actual 90m sieve.


3/9

2 | P a g e

MATERIAL : Ordinary Portland cement

PROCEDURE : Procedure to determine fineness of cement

i. 10g of cement to the nearest 0.01g was weighed

approximately and placed it on the sieve.

ii. The sieve agitated by swirling, planetary and linear

movements, until no more fine material passes through it.

iii. The timer was started when the sieve agitated was started.

iv. The residue Weighed and expressed its mass as a

percentage R1, of the quantity first placed on the sieve to

the nearest 0.01 percent.

v. Gently brushed all the fine material off the base of the

sieve.

vi. Repeat the whole procedure using a fresh 10g sample to

obtained R2 and R3. Then calculate R as the mean of R1

and R2 as a percentage average, expressed to the nearest

0.1 percent. When the results differ by more than 1

percent absolute, carry out a third sieving and calculate

the mean of the three values.


4/9

3 | P a g e

RESULT

R1 R2 R3

Weight of sieve 260.2 g 260.3 g 260.2 g

Weight of sieve + sample 270.2 g 270.3 g 270.2 g

Weight of sieve + sample retained 269.6 g 269.6 g 260.6 g

Sample retained on sieve 0.6 0.7 0.4

Percentage weight of residue 6% 7% 4%

% Weight of Residue , R1 = Weight of Sample Retained on the SieveTotal Weight of the Sample


5/9

4 | P a g e

DISCUSSION

For concrete containing no entrained air, there is a slight decrease in the static modulus of

elasticity at 28 days' age as the fineness is increased. The modulus of elasticity of concrete

determined by sonic methods decreases as the fineness of the cement increases. The fineness

of cement influences the drying shrinkage of concrete. When the water content is increased

because of fineness, the drying shrinkage is increased. However, if excessive bleeding due to

coarseness of the cement takes place, a reduction in the drying shrinkage occurs. The

resistance of air-entrained concrete to deterioration caused by freezing and thawing decreases

with an increase in cement fineness. The same trend is noted with non air-entrained concrete,

but to a lesser degree.

Limits:

The percentage residue should not exceed 10%.

Precautions:

Sieving shall be done holding the sieve in both hands and gentle wrist motion, this will

involve no danger of spilling the cement, which shall be kept well spread out on the screen.

More or less continuous rotation of the sieve shall be carried out throughout sieving.

Washers, shots and slugs shall not be used on the sieve. The underside of the sieve shall be

lightly brushed with a 25 or 40mm bristle brush after every five minutes of sieving.

Mechanical sieving devices may be used, but the cement shall not be rejected if it meets the

fineness requirement when tested by the hand method.


6/9

5 | P a g e

CONCLUSION

The air-void system in air-entrained concrete or concrete containing no entrained air is not

significantly affected by variations in the fineness of cement. The 28-day compressive

strength of concrete, with or without entrained air, increases with an increase in cementfineness. The difference in compressive strength due to difference in fineness of cement is

considerably less at 1 year's age. Both air-entrained and non air-entrained concrete containing

100 percent reactive aggregate are detrimentally affected by increased expansion at all ages

by increases in the fineness of high-alkali cement. Very coarse cement under some conditions

can cause a serious bleeding problem on some construction projects. When a cement is used

that meets the present Federal specifications, it is doubtful that a field construction problem

could be greatly influenced by changing the cement fineness.


7/9

6 | P a g e

QUESTIONS

1. Why do you need to do this for cement?

The tests should be performed to determine the characteristics of cement and its

compatibility with other materials in the concrete mix design.

2. What the implication of fineness cement to the concrete mixture?

Here are the conclusions offered in a paper by E. C. Higginson on "The Effect of

Cement Fineness on Concrete":

1. Increasing the fineness of cement reduces the amount of bleeding in concrete.

This is more pronounced for concrete containing no entrained air.

2. Increasing the fineness of cement from 2700 to about 4000 cm2/g reduces the

water requirement of concrete. Increasing the fineness of cement beyond an

optimum limit increases the water requirement of concrete.

3. The workability of non air-entrained concrete is increased by increasing the

cement fineness. In air-entrained concrete the effect of fineness of cement on

workability is very much less pronounced.


8/9

7 | P a g e

APPENDIX

bristle brush Portland cement

90 m IS Sieve Balance


9/9

8 | P a g e

REFERENCE

1. http://www.concreteconstruction.net/concrete-articles/cement-fineness.aspx

2. http://en.wikipedia.org/wiki/Cement
http://www.concreteconstruction.net/concrete-articles/cement-fineness.aspxhttp://www.concreteconstruction.net/concrete-articles/cement-fineness.aspxhttp://en.wikipedia.org/wiki/Cementhttp://en.wikipedia.org/wiki/Cementhttp://en.wikipedia.org/wiki/Cementhttp://www.concreteconstruction.net/concrete-articles/cement-fineness.aspx

Documents

Fineness Test (concrete)