Compound modification of asphalt mixture using ethylene-vinyl acetate copolymer and amorphous poly alpha olefin

Abstract

In this paper, an investigation on using recycled waste plastic EVA (ethylene–vinyl acetate copolymer) and APAO (amorphous poly alpha olefin) as modifiers in asphalt mixture was carried out. 6% APAO + 2% EVA, 4% APAO + 2% EVA and 6% APAO modified asphalt mixtures were prepared. In order to assess the performance of compound modified asphalt mixture, the Marshall, rutting, resilient modulus, indirect tensile strength (ITS), water stability, fatigue performance and aging performance tests were conducted. Compared with base asphalt, the Marshall stability, rutting resistance, water stability as well as fatigue performance of APAO/EVA compound modified asphalt mixture were improved evidently. Compared with SBS modified asphalt mixture, 6% APAO + 2% EVA modified asphalt represented the better deformation resistance, the resilient modulus increased by 76.1%. And anti-aging performance of APAO/EVA compound modified asphalt was also much better than that of SBS modified asphalt mixture. As for low-temperature ITS test, the stiffness modulus of 6% APAO + 2% EVA compound modified asphalt mixture decreased by 30.7%, which indicated better low-temperature flexibility. It was found that the performance of APAO/EVA modified asphalt mixture is much better than base asphalt and even better than SBS asphalt mixture in some respects. Therefore, using APAO and EVA to compound modified asphalt is an effective way to improve the performance of mixture and recycle waste plastic EVA.