Performance evaluation of asphalt mixture using polyethylene glycol polyacrylamide graft copolymer as solid–solid phase change materials

Abstract

Phase change materials (PCM) have the ability to store and release thermal energy which can be used in asphalt concrete pavements to regulate the working temperature of the pavement. To ensure the stability of PCM, polyethylene glycol-polyacrylamide graft copolymer was prepared as phase change material (PPGC-PCM) by graft copolymerization. In this study, the effects of PPGC-PCM on the performance of different asphalt mixture types were discussed. Three types of asphalt mixtures (AC-10, AC-13 and AC-16) were prepared under control (without PPGC-PCM) and five modified asphalt mixtures (with different PPGC-PCM additions). The effects of PPGC-PCM on the mechanical properties, moisture resistance, high temperature performance, and low temperature crack resistance of different asphalt mixtures were analyzed. The influence of PPGC-PCM addition on the thermal properties of different asphalt mixtures types was analyzed by non-stationary thermal conductivity test. The results show that compare with the control asphalt mixture, the Marshall stability and flexural-tensile strain of AC-10, AC-13, and AC-16 asphalt mixture with PPGC-PCM were increased by 8.86%, 5.41%, 4.94% and 16.2%, 16.8%, 14.3% respectively. The addition of PPGC-PCM could improve the moisture resistance, low temperature crack resistance, and thermal insulation properties of asphalt mixture. It has negative impact on the mechanical strength and long-term high temperature stability performance. The smaller the maximum nominal particle size (MNPS) of the asphalt mixture is, the greater impact of the PPGC-PCM addition has on the mechanical properties, while, the more significant changes in thermodynamic properties of asphalt mixture. Based on comprehensive analysis of testing groups, in order to achieve the optimum balance of properties in the asphalt mixture, for the adding proportion of PPGC-PCM, 7.5% is recommended to be used in AC-10 and AC-13 and 10.0% is recommended to be applied in AC-16.