Evaluation of pavement responses and performance with thermal modified asphalt mixture

The thermal properties of asphalt mixture play an important role in determining asphalt pavement temperature and accordingly viscoelastic pavement responses under vehicular loading. This paper aims to quantify the effect of thermal modified asphalt mixture on pavement responses and performance. A validated microstructure model of asphalt mixture was developed to predict thermal properties of asphalt mixtures with different thermal additives. The three-dimensional (3-D) finite element (FE) models were developed to predict temperature fields in the pavement structure and critical pavement responses under vehicular loading. The accuracy of the 3-D FE model was validated with field measurements. The critical responses in different thermal-modified pavement structures were analyzed. The long-term pavement performance including rutting and fatigue cracking were evaluated using the mechanistic-empirical analysis procedure. The analysis results show that using low-conductivity asphalt mixture in the surface course and high-conductivity asphalt mixture in the deeper layer decreased rutting effectively at high temperature and moderate temperature, but increased rutting slightly at low temperature. Using low-conductivity asphalt mixture in the pavement, especially in the upper layers could effectively improve the resistance to fatigue cracking at high temperature and moderate temperature, but slightly decrease the fatigue cracking resistance at low temperature. Finally, thermal-modified pavement structures that can improve both rutting and fatigue cracking resistance effectively were recommended.