Aggregates Crushing Value Test

GOAL;

To find the aggregate(course) crushing value under gradually applied compressive load. Which pass from 1.5mm. IS sieve and retained on 10mm. Is sieve.


APPARATUS;

1. Steel Cylinder (15 cm dia)
2. Cylindrical metal measure
3. Tamping Rod (45 to 60cm long)
4. Balance (0 To 10kg)
5. Sieves (12.5mm to 10mm)
6. Oven (3000c)
7. Compression testing Machine (2000KN)  

 SAMPLING;

Course Aggregates  passing on 12.5mm IS Sieve and retained on 10mm IS sieve and dried at 100 to 110°C  Oven for a period of not less than 4 hours. The sample should  cooled at room temperature.

PROCEDURE;

1. Put the cylinder at right position on the Base plate and weigh it (W).
2. Put the Aggregates Sample in three Equal Layer, each layer is tamped 25time using the tamping rod,avoid the breakage of weak material and weigh it (W1).
3. The surface of aggregates is then leveled carefully and inserts the plunger, Care being take and ensure that the plunger does not jam due to the remaining particle on side in the cylinder.
4. Apply load on the apparatus place in the compression testing machine at a uniform rate so that a total load of 40tones in 10minutes .After this , the load is released.
5. Sieve the aggregates sample with 2.36mm IS sieve and fraction passing through the sieve is weighed (W2).
6. This process should be repeated two time. 

CALCULATION; 

The ratio of weight of fine formed to the total weight sample in each test shall be expressed in percentage.

Aggregate crushing value = (W2x100) / (W1-W)
W2 =Weight of fraction passing through the sieve
W1 =Weight of surface dry sample.
W=Weight of cylinder.

Two result to the nearest whole number is the aggregate crushing value.

Result; 
Aggregate crushing value =