Optimization of waste high-density polyethylene content based on performance evaluation of asphalt mixtures

To determine the optimal dosage of waste high-density polyethylene (WHDPE), a comprehensive evaluation of the modified asphalt mixture was conducted through a series of tests focusing on water stability, high-temperature stability, fracture resistance, and fatigue resistance. The results indicated that WHDPE enhances the water stability of asphalt mixtures, with the best modification effect achieved when the dosage is between 8% and 10%. WHDPE exhibits a linear improvement in stability, with an enhancement rate ranging from 11% to 57%. The rutting depth of the mixture containing 6% WHDPE decreased by 72.4% compared to the control group, but the reduction slowed down as the dosage continued to increase. When the WHDPE content is at 8%, the mixture exhibits optimal fracture resistance and fatigue resistance. After a comprehensive analysis of the improvement effects on various performance indicators, it is recommended that the optimal dosage of WHDPE be set at 8%. However, if there are special requirements for the service environment, the aforementioned modification rules can serve as a reference for optimal dosage selection.