Method of Estimating Compressive Strength of Concrete by Hammer Blow

摘要

PROBLEM TO BE SOLVED: To provide a new estimation method of a new concrete compression strength in place of a conventional rebound method and a mechanical impedance method.SOLUTION: A striking part 3a of a striking hammer 3 having a radius R of a spherical crown part strikes a top surface 2 of a concrete system structure H by a striking hammer 3 having a weight M and takes a measured time history acceleration a(t) into the analysis processing device 6. In the analysis processing device 6, if a collision speed Vof the striking hammer is calculated by time-integrating the time history speed a(t) during the time in which the acceleration becomes a maximum from 0 and the maximum value Fmax of the time history striking force F(t)(=M(hammer weight×a(t))is obtained, then, the dynamic Brinell hardness value His calculated by a formula (15), and the compression strength of the concrete is estimated based on a correlation formula showing a relationship between the dynamic Brinell hardness value Hand the concrete compression strength.