IS 9845 provides the aggregate impact value (AIV) test — a quick field test for aggregate toughness. AIV = percentage of fines passing 2.36mm sieve after 15 standard blows. Lower AIV = tougher aggregate. Critical for road and pavement aggregate selection.
Method of test for determining the aggregate impact value (AIV) which gives a relative measure of the resistance of aggregate to sudden shock or impact.
Key Values
Max AIV for wearing course30%
Max AIV for concrete aggregate45%
Number of blows15
Practical Notes
! AIV < 30% is required for road wearing course aggregates per IRC specifications.
! This is a quick test (15 minutes) and can be done on site with portable equipment.
! AIV and crushing value (IS 9376) together give a good picture of aggregate strength.
! Wet AIV is also tested — if wet AIV > 1.25 × dry AIV, the aggregate is moisture-sensitive.