桥面铺装用聚氨酯/环氧树脂改性沥青的性能研究

Study on Performance of Polyurethane/Epoxy Resin Modified Asphalt for Bridge Deck Pavement

为了提高钢-超高性能混凝土组合桥面沥青铺面层的使用寿命,利用聚氨酯/环氧树脂对沥青结合料进行改性。通过红外光谱试验、荧光显微镜试验对聚氨酯/环氧树脂改性沥青的固化进程进行了表征。分别采用了聚合物改性沥青离析试验、布氏旋转黏度试验、拉伸试验测试了改性沥青的储存稳定性、黏时特性和力学性能。借助动态剪切流变仪试验和低温弯曲梁流变仪试验研究了改性沥青的高低温性能。试验结果表明:在固化过程中,聚氨酯/环氧树脂与复配胺类固化剂发生开环反应并逐步形成了聚合物互穿网状(IPN)结构,聚氨酯/环氧树脂相由分散相转变为连续相,改性沥青的黏度先缓慢增长至凝胶点后快速拉升并且受固化温度和改性剂掺量的影响较大;聚氨酯/环氧树脂改性沥青因IPN结构的骨架作用具有超高的拉伸强度和较好的柔韧性,而且相较于普通环氧沥青,低温性能得到改善;聚氨酯/环氧树脂能够大幅提高沥青的高温抗车辙能力,其改善效果随着掺量的增加而增强;35%改性剂掺量的聚氨酯/环氧树脂改性沥青拥有最好的储存稳定性。

In order to extend the service life of asphalt pavements for steel-ultra-high performance concrete(UHPC) composite bridge deck, the asphalt binder is modified with polyurethane/epoxy resin. The curing process of polyurethane/epoxy resin modified asphalt is characterized by infrared spectrum test and fluorescence microscope test. The storage stability, viscosity characteristics and mechanical properties of modified asphalt are tested by polymer modified asphalt segregation test, Brookfield rotational viscosity test and tensile test. The high and low temperature performances of modified asphalt are studied by using dynamic shear rheometer test and low temperature bending beam rheometer test. The test result shows that(1) during the curing process, the polyurethane/epoxy resin and the compound amine curing agent undergo ring-opening reaction to form the polymer interpenetrating network(IPN) structure, the polyurethane/epoxy resin phase changed from the dispersed phase to the continuous phase, the viscosity of modified asphalt first slowly increased to the gel point then rapidly rose, and the viscosity is greatly affected by the curing temperature and the content of modifier;(2) the polyurethane/epoxy resin modified asphalt has ultra-high tensile strength and better flexibility due to the skeleton effect of IPN structure, and its low-temperature performance is improved compared with ordinary epoxy asphalt;(3) polyurethane/epoxy resin can greatly enhance the high-temperature rutting resistance of asphalt, the improvement effect increases with the increase of modifier content;(4) the polyurethane/epoxy resin modified asphalt with 35% modifier content has the best storage stability.