Laboratory Evaluation of the Effect of Waste Rubber Powder and Recycled Polyethylene Waste Powder on the Functional Properties of Bitumen and Asphalt Mixture with an Environmental Approach

Due to the significant increase in traffic volume, asphalt pavements gradually deteriorate and their two main failure modes are delamination at high temperature and thermal cracking at low temperature. This paper focuses on the modification of bitumen and asphalt mixtures with the aim of improving the performance of asphalt pavement simultaneously at high and low service temperatures. To modify the properties of bitumen, shredded recycled rubber (CR1) and polyethylene (PE) 2 were selected as polymer agents. The performance analysis of the rheological properties of the modified bitumen showed that the addition of CR reduced the creep stiffness of the bitumen at low temperature, thereby reducing the risk of failure and cracking. Meanwhile, the addition of PE increased the high temperature stiffness of bitumen, which resulted in improved roughness resistance. In the case of modified integrated bitumen, the addition of CR and PE simultaneously improves bitumen properties at both high and low temperatures. In terms of asphalt mixture, PE increases the resistance to permanent deformation at high service temperature while CR increases ductility at low service temperature. The integrated mixture modified with CR and PE had significantly improved performance at both high and low service temperatures. Therefore, the use of these two recycled materials is able to improve the pavement properties to the extent or even better than those obtained by using bitumen modified with styrene-butadiene-styrene.