Aggregate Impact Testing Machine

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 accuracy 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.

The Apparatus consists of following:-

• A Testing Machine having a metal base with a painted lower surface of not less than 30cm in diameter. It is supported on level and plane concrete floor of minimum 45cm thickness. The machine have provisions for fixing its base.
• A Cylinderical cup of internal diameter of 102mm, depth 50mm and minimum thickness 6.3mm.
• A metal hammer or tup weighing 13.5 to 14 kg the lower end being cylindrical in shape, 50mm long, 100.0mm in diameter with a 2mm chamfer at the lower edge and case hardened. The hammer will slide freely between vertical guides and be concentric with the cup. Free fall of hammer will be within 380 + 5 mm
• A Cylinderical metal measure having internal diameter 75mm and depth 50mm for measuring aggregates.
• Tamping Rod 10mm in diameter and 230mm long, rounded at one end.