热固性聚氨酯改性沥青桥面铺装材料制备及性能研究

Preparation and performance research of thermosetting polyurethane modified asphalt bridge deck pavement materials

为研究热固性聚氨酯改性沥青(TPUA)桥面铺装材料的制备及性能变化规律,基于响应曲面法,以桥面铺装性能最优为目标,并结合层次分析法对TPUA混合料的制备工艺进行优化;对比SBS沥青和环氧沥青混合料,对不同改性剂掺量下的TPUA混合料进行综合性能分析。研究结果表明:在恒温养护条件下,TPUA混合料强度随时间的变化过程满足指数增长关系,且温度对于TPUA混合料的强度形成具有促进作用;在PU改性剂掺量超过30%后,TPUA混合料具有比传统SBS沥青混合料更加优异的力学性能、水稳定性和高温抗变形性能;此外,在室温下,TPUA混合料具有比环氧沥青和SBS沥青混合料更优异的抗断裂性能;TPUA混合料的低温最大弯拉应变能够达到8000με,且低温断裂能为对比组混合料的3倍以上,具有优异的低温柔韧性。

To study the preparation and performance change law of thermosetting polyurethane modified asphalt(TPUA)bridge deck pavement materials,based on the response surface method,aiming at the optimal performance of bridge deck pavement,and combined with the analytic hierarchy process,the preparation process of TPUA mixture for bridge deck pavement was optimized.The comprehensive performance of the TPUA mixture with different modifier dosage was analyzed by comparing the SBS asphalt and epoxy asphalt mixture.The results show that the change process of TPUA mixture strength with time conforms to the exponential growth under the condition of constant temperature curing.Temperature can promote the strength formation of the TPUA mixture.When the dosage of the PU modifier exceeds 30%,the TPUA mixture has better mechanical properties,water stability and high-temperature deformation resistance than those of the SBS asphalt mixture.In addition,the TPUA mixture has better fracture resistance than that of epoxy asphalt and SBS asphalt mixture at room temperature.At low temperature,the maximum flexural tensile strain of the TPUA mixture can reach 8000με,and its low-temperature fracture energy is more than 3 times of the control groups.TPUA mixture has excellent lowtemperature flexibility.