Study on piezoelectric wave propagation based nondestructive monitoring method of concrete

In order to monitor the basic mechanical properties and interior local damage of concrete structures, the piezoelectric actuator/sensor based wave propagation method is investigated experimentally. A test setup for wave propagation monitoring is established in the lab. The energy attenuation of stress waves is measured by the relative index between the output voltage of sensors and the excitation voltage at the actuator. Based on the experimental results of concrete cube and cylinder specimens, the effect of excitation frequencies and amplitude, wave propagation paths and the curing age on the output signals of sensors are investigated. The results show that the relative voltage attenuation coefficient RVAC is an effective indicator for measuring the attenuation of stress waves through the interior of concrete.