| 摘要 |
PROBLEM TO BE SOLVED: To estimate concrete strength with high reliability by using plural measured data provided on impact. SOLUTION: A resiliency sensor 12 for detecting resiliency of a test hammer 11a rebounding by a strike for a concrete 2 is provided in a impact apparatus 11. An acceleration sensor 15 for detecting vibration generated in the concrete 2 by the impact and propagated on its surface is provided in a prescribed position of the surface of the concrete 2. Detection of the resiliency by the resiliency sensor 12 and the vibration detection by the acceleration sensor 15 are carried out at the time of the impact. Detected signal from the sensor 15 is A/D- converted, wave form parameters such as a dominant frequency, the maximum amplitude value and an AR coefficient are analyzed by signal processing, and concrete strength is found by a personal computer 20 from analyzed data of the resiliency data mentioned above, the dominant frequency, the maximum amplitude value, the AR coefficient and the like. |
