Prototype Design of Cement/Emulsified Asphalt Based Piezoelectric Composites and its Potential Application in Vehicle Speed Sensing

Abstract

Piezoelectric composites (PC) embedded in pavement have shown great potential in traffic information sensing. As the main form of transportation, the road is the source of much traffic information including vehicle load information. The research into PC can supplement the collection of traffic information used in the development of intelligent technologies and provide effective solutions to problems existing in the process of information gathering. In this study, a 2-2 cement/emulsified asphalt-based PC was prepared with the cutting-filling method. To optimize the PC preparation, the effects of the volume fraction of the piezoelectric phase and the matrix phase composition on the piezoelectric properties of the PC were investigated by employing the finite element method. The results indicated that the smaller the volume fraction of the piezoelectric phase, the higher the voltage output of the PC, and the higher the sensitivity to external load, but the greater the stress concentration at the interface between the piezoelectric phase and the matrix phase. In addition, the greater the amount of emulsified asphalt in the matrix phase, the higher the voltage output of the PC. However, a higher content of emulsified asphalt will undermine the fluidity of the matrix phase. Based on the simulation analysis, performance optimization of the cement/emulsified asphalt PC was achieved. According to the voltage output characteristic of PC under a moving load, a placement scheme of PCs in the asphalt pavement was also proposed, which enables vehicle speeds to be be sensed with high precision.