Rebound hammer test for concrete

Rebound Hammer testing is a non-destructive method of determining the compressive strength of concrete that offers an easy-to-use and quick indication. The rebound hammer, which is also known as a Schmidt hammer, is made out of a mass controlled by a spring that travels along a plunger inside of a tubular housing. Figure 1 depicts the rebound hammer in action. A spring-controlled mass with consistent energy is made to hit the surface of the concrete when the plunger of the rebound hammer is pressed against it.

On a graded scale, the amount of rebound, which measures surface hardness, is measured. Rebound Number is the name given to this measured number (rebound index). Low strength and stiffness concrete will absorb more energy, resulting in a lower rebound value.

The premise behind the rebound hammer test method is that an elastic mass' ability to rebound is dependent on how hard the concrete surface it strikes is. The spring-controlled mass in the rebound hammer bounces back when the plunger is pressed against the concrete surface.