Aggregate Impact Tester

**AGGREGATE IMPACT HAMMER** is a heavy, typically cylindrical metal hammer used in a laboratory testing apparatus to measure the resistance of aggregate particles to sudden impact by repeatedly dropping it onto a sample of aggregate, thus determining the **"aggregate impact value"**, which indicates how well the material can withstand shock loads; it is usually part of a machine with a fixed height for the hammer drop and a mechanism to count the number of blows delivered.