Schmidt Hammer/Rebound Hammer
Rebound Hammer Test
This is a non-destructive test method to evaluation of compressive strength of concrete with spring-loaded hammer in accordance with ASTM C805.
This test is conducted when the need for knowing concrete strength of RC member is raised; old or new RC members need to be checked for their concrete strength for further analysis, and evaluation or to verify the design strength with actual strength of given RC members.
Rebound hammer will give the rebound index corresponding to concrete condition then compressive strength of concrete will be determined by using conversion chart between concrete strength (in cube or cylinder) versus rebound index in accordance with each type of rebound hammer.
Some of our past projects pointed out that actual concrete strength in some RC members is too low, construction quality is too poor, leading to the demolition of old concrete and replacement by new concrete casting.