Sieve Analysis Of Concrete Mixture

CHAPTER 3

EXPERIMENTAL PROGRAMME

3.1. GENERAL

The main objet of this experimenta is to compare the properties of concrete made with and without plastic aggregates, that is used as coarse aggregate in concrete mix. Major tests carried out on materials used for casting the concrete samples are discussed in this section, a brief description about mix deign and curing procedure used and at the end, the various tests conducted on the specimens are discussed.

3.2. MATERIALS USED

3.2.1. Cement

Cement is a fine and grey powder. When it is mixed with water and materials such as fine aggregates, coarse aggregates and crushed stone, it make bond with them. Cement and water form a mix that binds the materials together as the concrete harden. Ordinary

Coarse aggregates

Aggregates which are retained on 4.75-mm IS Sieve conforming IS 383- 1970 are known as coarse aggregate. Coarse aggregate are the main load bearing component of concrete. Locally available coarse aggregate having the size of 20 mm was used in our work. figure 3.4 shows the sieve shaker apparatus used for the sieve analysis of aggregates. Table 3.5 shows the properties of coarse aggregate used in experimental work. For finding the fineness modulus sieve analysis for coarse is being done. In table 3.6 the sieve analysis is described as per the study was done.

Table 3.5 Properties of Coarse aggregates

Sr.no. Characteristics Values

1. Type crushed

2. Maximum size 20

3. Specific gravity 2.75

4. Total water absorption 0.5%

5. Fineness modulus 6.61

Table 3.6 sieve analysis of Coarse aggregates

S.No. IS-Sieve (mm) Wt. Retained (gm) %age Retained %age passing Cumulative % retained

1 80 0.00 0.00 100.00 0.00

2 40 0.00 0.00 100.00 0.00

3 20 447 22.35 77.65 22.35

4 10 415 20.75 56.90 43.1

5 4.75 1055 52.75 4.15 95.85

6 2.36 80 4.0 0.15 99.85

7 1.18 0 0 0 100

8 600 0 0 0 100

9 300 0 0 0 100

10 150 0 0 0

iii) Mix the dry constituents thoroughly to get a uniform colour and then add water. Place the mixed concrete in the cleaned slump cone mould in 4 layers, each approximately ¼ of the height of the mould. iv) Each layer is tamped 25 times by the rounded end of the tamping rod (strokes are distributed evenly over the cross section). vi) After the top layer is rodded, the concrete is struck off the level with a trowel. vii) The mould is removed from the concrete immediately by raising it slowly in the vertical direction. viii) The difference in level between the height of the mould and that of the highest point of the subsided concrete is measured. This difference in height in mm is the slump of the concrete.

3.5.2 COMPRESSIVE STRENGTH TEST

After 28 days of curing compressive strength test is done. Then cubes are taken to the lab after finishing the curing and density measurement. The samples are entered into the Compressing Testing Machine (CTM) to determine compressive strength after measuring its dimension to determine its contact surface