CRTSⅢ型板式无砟轨道底座伸缩缝用环氧沥青填缝密封胶性能研究

Study on Performance of Epoxy Asphalt Sealant for Base Expansion Joint of CRTSⅢ Slab Ballastless Track

根据CRTSⅢ型板式无砟轨道底座伸缩缝变形特性,制备了其专用的环氧沥青填缝密封胶,开展了拉伸性能及黏结性能试验,分析了不同温度条件下环氧沥青填缝密封胶应力-应变关系和失效模式,并对比了其与硅酮、聚氨酯填缝密封胶耐老化性能的差异。试验结果表明:环氧沥青填缝密封胶拉伸过程中应力-应变关系与温度密切相关,温度低于0℃时密封胶破坏前随应变增加应力近似呈线性减小,温度高于0℃时随应变增加应力不断增大直至破坏;环氧沥青填缝密封胶失效模式是其与混凝土基材之间产生离缝;环氧沥青填缝密封胶具有较好的耐老化性能,紫外老化和浸水老化对环氧沥青填缝密封胶性能影响较大,热老化影响相对较小。

According to the deformation characteristics of expansion joint of CRTSⅢ slab ballastless track base,the special epoxy asphalt joint sealant was prepared,and tensile performance and bonding performance tests were carried out.Stress-strain relationship and failure mode of epoxy asphalt joint sealant under different temperature conditions were analyzed.The difference in aging resistance performance of epoxy asphalt joint sealant,silicone joint sealant and polyurethane joint sealant was compared.The test results show that the stress-strain relationship is closely related to temperature during the tensile process of epoxy asphalt joint sealant.When the temperature is lower than 0℃,the stress of sealant decreases linearly with the increase of strain before failure.When the temperature is higher than 0℃,the stress increases with the increase of strain until failure.The failure mode of epoxy asphalt joint sealant is the separation between it and the concrete base material.The epoxy asphalt sealant has good aging resistance performance.Ultraviolet rays aging and immersion aging have a greater impact on the performance of epoxy asphalt sealant,while thermal aging has a relatively small impact.