Research on a 0-3 cement-based piezoelectric sensor with excellent mechanical-electrical response and good durability

In this study, a novel cement-based piezoelectric sensor was prepared with 0-3 cement-based piezoelectric composites as the sensing element and a mixture consisting of epoxy resin and cement as the encapsulation part, and its mechanical-electrical response measurement was carried out by dynamic load. To realize effective load transmission from the structural material to the sensing element, and to better evaluate and improve the sensor durability, the optimum encapsulation system and sensing element location were explored, and the durability of the cement-based piezoelectric sensor under complicated conditions was studied in detail. Results indicated that the sensor possessed excellent linear performance, with the regression confidence exceeding 0.99 in a large range of 0.31-2.34 MPa, when the ratio of cement to epoxy resin was 3:1 and the sensing element was put in a position near the underside of the encapsulation material. The phase shift between the output voltage and input load was nearly zero and the sensor could respond to pulse load quickly. Environmental conditions including fatigue load and water had a negligible effect on the linearity and sensitivity (slope of fitting line) of the sensor, and in the intended temperature range of 0-40 degrees C the sensor showed good linearity, almost independent of temperature; nevertheless, the output voltage increased with increasing temperature and the sensitivity reached 1811 mV MPa-1 at 40 degrees C. Generally, the sensor prepared in this research had excellent mechanical-electrical response and good durability.