Evaluation of Mechanical and Sensing Performance of a New Sensor-Enabled Piezoelectric Geosynthetic Material

Geosynthetics are widely used in reinforced soil engineering because of their excellent performance. Currently, an increasing number of researchers are studying the fabrication of geosynthetics with both reinforcement functions and sensing abilities. Sensor-enabled piezoelectric geobelts (SPGBs) have great potential in the field of integrated soil reinforcement monitoring because of their ability to reinforce and sense soil. In this paper, polymer-based SPGBs that can be batch extruded were successfully prepared using high-density polyethylene (HDPE), polyolefin elastomer (POE), carbon black (CB), and piezoelectric ceramics (PZT), and the preparation rate of SPGBs was substantially improved. Laboratory tensile tests were conducted to test the strain–stress–impedance–voltage signals of SPGB in the tensile process at 45 different ratios. The results showed that the piezoelectric strain constant (d33) of SPGBs was up to 10.5 pC/N. The tensile strength and breaking strain of SPGBs reached their maximum values of 14 MPa and 26.37%, respectively, at 65% PZT content. During the tensile test, the SPGB normalized impedance increased with increasing strain, and there was a significant sudden increase at the time of damage. An empirical formula for strain-normalized impedance, which can be used to calculate the strain of SPGBs quantitatively, was established. The SPGB output voltage rapidly increased and then decreased with increasing strain, and two characteristic points can be used as warning signs to qualitatively describe the change of SPGBs. The results of this study can provide a design basis for the batch preparation of SPGBs in engineering.