Rebound Hammer Test: An Investigation into Its Reliability in Applications on Concrete Structures

Figure 8

Calibration curves for different specimen mass and stress state. Dotted bold line: Schmidt curve. Calibration curve: R_c = e^aRI; RI = rebound index; a ∈ [0.088, 0.110]; R²≅[0.66, 0.93]. Inside any dataset, C.o.V. ≤ 9% for vanishing stress; C.o.V. ≤ 10% for compressed prisms (5 and 10 MPa, 200 kN).