3.2.3.1 Aggregate Impact Value (AIV)
The AIV was incorporated into the British Standards in 1955 as a measure of crushed rock strength. A sample of lumps (14-10mm) is impacted with a piston fifteen times and the product is sieved using a 2360ï?m aperture. The percentage material passing denotes the AIV. The test is then repeated and should be within a numerical range of one.