Impact test on aggregate (IS:5640-1970)
Objective - To determine the impact value of given road aggregate. Apparatus & materials required - Impact testing machine. A cylindrical metal having internal diameter 75 mm and depth 50 mm. Tamping rod of 10 mm diameter and 230 mm long. IS sieve of sizes 12.5 mm, 10 mm and 2.36 mm. Balance Thermostatic oven Aggregate sample Theory - The aggregate impact value indicates a relative measure of the resistance of an aggregate to impact. The aggregate impact value is expressed as the percentages of fines formed in terms of the total weight of the sample. Due to traffic loads, the road aggregates are subjected to impact and and there is possibility of aggregates breaking into smaller pieces. The road aggregate should be tough enough to resist fracture under impact. A test designed to evaluate the toughness of aggregate is called aggregate impact test. ...