排水性沥青路面粘结层抗剪性能的试验研究

Experimental study of shear behavior of cohesive layer of porous asphalt pavement

通过室内模拟试验,利用长沙理工大学研制的斜面剪切仪,在50mm/min的剪切速率下,分别对涂刷环氧沥青、改性乳化沥青、SBS改性沥青和高粘沥青等4种粘结材料的复合试件进行斜面剪切试验,分析其在不同的环境条件下的剪切强度变化规律.分析结果表明:粘结层剪切强度随其用量的增加先增后减,即存在一个最佳用量;剪切强度随温度的升高而降低,其中环氧沥青剪切强度下降最快,即对温度最为敏感;4种材料抵抗水侵蚀能力由大到小的顺序依次为:环氧沥青、改性乳化沥青、SBS改性沥青和高粘沥青;冻融循环对防水粘结层剪切强度影响很大,冻融循环两次后,其剪切强度下降近50%.

Through the laboratory simulation test,under 50 mm/min shear rates,the bevel shear test of combined specimen which was brushed by four kinds of cohesive materials which are epoxy asphalt,modified emulsion asphalt,SBS modified asphalt and high-viscosity asphalt.The changes of shear strength under different environmental conditions were analyzed using the slant shear apparatus which is developed by Changsha University of Science Technology.The analysis results show that shear strength of cohesive layer is gradually promoted and then reduced with the increase of the amount of cohesive materials.Shear strength has the opposite response on the ambient temperature,among which the shear strength of epoxy asphalt reduced fastest,and is the most sensitive to temperature.The order of the four materials resistant to water erosion is epoxy asphalt,modified emulsified asphalt,SBS modified bitumen and high-viscosity asphalt.Shear strength of cohesive layer was affected by freeze-thaw cycle enormously.The shear strength has dropped nearly 50% after twice of freeze-thaw cycle.