Self-Healing Capability and Mechanical Properties of Asphalt Mixtures Prepared With Light-Activated Polyurethane Prepolymer Modified Asphalt Binder

Abstract

The objective of this study was to develop a new generation of ultraviolet (UV) light-activated self-healing polyurethane prepolymer modified asphalt binder using a reactive approach and to optimize the production parameters. Rheological tests were conducted on the prepared binder blends to evaluate the effect of the modification on rutting and fatigue cracking. The effect of the modification on asphalt mixtures was also evaluated using a self-healing experiment and various mechanical laboratory tests. The formation of urethane bond was confirmed using Fourier transformed infrared spectroscopy (FT-IR). Rheological test results of the modified binder demonstrated an increase in the high-temperature grading, while no significant effect was observed on the low-temperature grade. Self-healing testing of the asphalt mixtures showed that mixtures with 10% polymer and continuous exposure to UV light exhibited the highest crack healing rate. Loaded Wheel Tracking (LWT) results showed an improvement in rutting resistance of the mixtures prepared with polymer. In addition, Semi-Circular Bending (SCB) test results showed an improvement in the cracking resistance with 5% polymer. An increase in high-temperature grade was also observed for the extracted binders from the prepared asphalt mixtures. Multiple Stress Creep Recovery (MSCR) test results of the extracted binders showed an improvement in the elastic behavior and rutting resistance with an increase in polymer content. Furthermore, the extracted binders from aged mixtures showed an improved fatigue performance with the increase in polymer content.