冷拌聚氨酯改性沥青混合料路用性能研究OA

To investigate the effects of polyurethane prepolymer type and the liquid asphalt-resin ratio on the strength and road performance of cold-mix asphalt mixtures,this study selected three polyurethane prepolymers with different NCO contents.Binders materials were prepared using liquid asphalt and resin at mass ratios of 1∶0.8,1∶1,and 1∶1.2,respectively.A 6％binder content was used to produce AC-10C graded cold-mix asphalt mixtures.A comprehensive evaluation was conducted,including tests on strength development,high-and low-temperature performance,moisture stability,and stripping resistance.The results showed that with increasing NCO content or resin ratio,the mechanical strength of specimens improved at all curing stages,though the rate of strength gain gradually declined.Therefore,when determining the optimal liquid asphalt-to-resin ratio,the influence of NCO content should be carefully considered.The study indicates that both NCO content and the asphalt-to-resin ratio are critical factors influencing the performance of the mixtures.Experimental results revealed that the polyurethane prepolymer-modified cold-mix asphalt mixtures exhibited significantly better high-temperature stability than the requirements specified for hot-mix asphalt in current standards,demonstrating excellent high-temperature performance.Moreover,cold-mix mixtures with higher NCO content also showed good adaptability to both high and low temperatures,along with improved moisture stability and stripping resistance.Overall,the study confirms that preparing cold-mix asphalt mixtures using polyurethane prepolymer-modified asphalt offers promising application potential.This approach provides an effective solution for rapid pavement repair and is expected to promote the broader adoption of polyurethane-based cold-mix asphalt technology.