Embedded Cement-Based Piezoelectric Sensors for Acoustic Emission Detection in Concrete

In this research, the feasibility of using embedded cement-based piezoelectric sensors to detect the acoustic emission (AE) activities in concrete has been studied. A sensor is presented that is made with the 0-3 cement-based piezoelectric composite as sensing element. The composite is formed by pressing mixed cement-piezoelectric powder into a penny-shaped thin plate. In the terminology of 0-3, 0 represents the dimension of the piezoelectric particle and 3 stands for the dimensions of the matrix. By adjusting the dosage of the piezoelectric ceramic powder, the properties of the composite can be tailored to suit designated applications. Sensors made of the composite (0-3 sensor) are able to be embedded into concrete and have broadband frequency response. It is shown by a four-point bending test on a concrete beam that the sensors have excellent ability in AE activity detection. High sensitivity is also observed for the embedded sensors.