Aggregate Crushing Value

AIM
To determine the aggregate crushing value of coarse aggregates as per

IS: 2386 (Part IV) - 1963. 

APPARATUS

CYLINDRICAL MEASURE AND PLUNGER

1. Cylindrical measure and plunger
2. Compression testing machine
3. IS Sieves of sizes - 12.5mm, 10mm and 2.36mm 

PROCEDURE

1. The aggregates passing through 12.5mm and retained on  10mm IS Sieve are oven-dried at a temperature of 100 to 110oC for 3 to 4hrs.
2. The cylinder of the apparatus is filled in 3 layers, each layer tamped with 25 strokes of a tamping rod.
3. The weight of aggregates is measured (Weight 'A').
4. The surface of the aggregates is then levelled and the plunger inserted. The apparatus is then placed in the compression testing machine and loaded at a uniform rate so as to achieve 40t load in 10 minutes. After this, the load is released.he sample is then sieved through a 2.36mm IS Sieve and the fraction passing through the sieve is weighed (Weight 'B').
5. Two tests should be conducted.

REPORTING OF RESULTS
                                               B
Aggregate crushing value = —--— x 100%
                                               A
The result should be recorded to the first decimal place and the mean of the two results reported.