Aggregate Impact Value Test

Aim: To conduct a test to determine aggregate impact value of coarse aggregate.

Note: Aggregate Impact Value gives a relative measure of the resistance of an aggregate to a sudden shock or impact which differs from crushing strength.

IS: 2386 Part IV.

Apparatus:

Impact Testing Machine, Tamping Rod, Sieves 12.5mm, 10mm and 2.36mm

Procedure:

-Take some coarse aggregate passing through 12.5mm sieve and retained on 10mm sieve, wash and oven dry for 4 hours.

-Take the wt. of empty cup. Put this in the cup in three layers while tamping 25 times.

- Weigh the aggregate with cup. Now fill the cup to the brim and further give 15 blows.

- Take a 2.36mm sieve and pass the impacted aggregate Note B and A values.

Calculation: Aggregate Impact Value= B x 100 /A

B= Fraction Passing

A= Fraction Retained