Performance Evaluation of Pelletized Solid Polymer Modified Asphalt Mixtures

The purpose of this research is to provide a comprehensive evaluation of the effects of a solid pelletized plastomeric polymer on asphalt mixtures’ properties and performance with respect to different distresses. Five asphalt mixtures—a control mixture (no polymer); asphalt mixtures with 2.5%, 5.0%, and 7.5% polymer content; and a mixture with 5% polymer and lower asphalt binder content—were evaluated. The laboratory testing campaign included complex modulus, direct tension cyclic fatigue, semi-circular bending, disk-shaped compact tension, and asphalt pavement analyzer tests. Advanced performance-based simulation programs—MnPAVETM, FlexPAVETM, and ILLITC—were utilized to predict mixture performance in the context of pavement structure and local traffic and climatic conditions. In addition, four field test sections were constructed for all but the mixture with the reduced binder content and falling weight deflectometer (FWD) testing was conducted on the test sections. Based on the results of laboratory testing and performance simulation it can be concluded that the study modifier significantly improved the rutting performance and slightly improved the mixture fatigue performance. The study modifier did not show a considerable positive or negative effect on the thermal cracking performance. Based on the FWD results, solid polymer is potentially a good option to increase the stiffness of the asphalt concrete (AC) layer.