Application of low-profile piezoceramic transducers for health monitoring of concrete structures

Using piezoceramic patches bonded on concrete beams to perform structural health monitoring is investigated in this paper. To evaluate the performance of piezoceramic sensors and ultrasonic wave methods, two series of tests were carried out on 100×100×500 mm3 concrete prisms. In the first series of tests, the influence of the frequency of the input signal on the waveforms was investigated and the optimum frequency to generate ultrasonic waves was evaluated. From the velocity of Rayleigh waves and longitudinal waves, the dynamic modulus of elasticity and dynamic Poisson's ratio of the concrete were obtained. In the second series, the effect of uniaxial compressive stress and the resulting internal cracking of the concrete on the amplitude of the waveforms received by piezoceramic sensors was investigated. It is shown that differences in amplitude between two wave packets are sensitive to the cracking process of concrete with externally applied loads. The results confirm that piezoceramic sensors and corresponding ultrasonic waves methods have the potential to monitor cracking and the long-term deterioration of concrete structures.