As per IS: 2386 (IV) 9377. This Apparatus is used to determine aggregate impact value of coarse aggregate. The hammer of the tester fall freely from 380 mm height on coarse aggregate for 15 times/15 sec.the crushed aggregate removed from the cup ,then sieved and weighed. The % ratio of the weight passing 2.36mm sieve and weight of oven dried sample is Aggregate Impact value.
Specification :The instrument consists of a circular base with two vertical guides. The hammer of weight 13.75 ±0.25 kg can be raised to fall freely down the vertical guides. The height of fall can be adjusted through 380 ± 5mm. The hammer is provided with a locking arrangement. The hammer falls freely to the base and is removable for emptying. Supplied complete with metal measures 75mm dia x 50mm high (for specimen preperation) and tamping rod 230mm long x 10mm dia.