The aggregate impact value of coarse aggregate provides a relative measure of the resistance of an aggregate to sudden shock or impact. The oven dried and accurately weighed aggregates are subjected to a total of 15 blows of specified weight and fall and percentage of fines formed in terms of the total weight of the sample is expressed as the aggregate impact value.
Consists of base weighing between 20-30 kg with a lower surface of not less than 30cm and support columns to form a rigid frame work around the quick release trigger mechanism to ensure an effective free fall of the hammer during test. The free fall can be adjusted through 380 + 5.0mm. The hammer is provided with a locking arrangement. A metal tup (hammer) weighing 13.5 to 14.0 kg, the lower end of in cylinderical shape, 100mm in diameter and 5cm long with a 2mm chamfer at the lower edge and case hardened. Complete with a cylindrical cup, 102mm dia x 50mm depth, one measure 75mm dia x 50mm deep and a tamping rod of circular cross section 10mm in diameter and 230mm long, rounded at one end.
Salient Features
- 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.
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