Rebound Hammer

Rebound hammer test is shown in above picture. The plunger usually pressed against a point on surface of concrete. A spring controlled mass with a constant energy hits concrete surface that rebounds back. The extent of rebound, which is a measure of surface hardness, measured on the calibrated graduated scale. The measured value is a recorded as Rebound number or rebound index.

This test is performed in accordance to Indian code IS: 13311(2)-1992 reaffirmed to 2013.