Influence Of Salt And Freeze-Thaw Split On Polyester Fiber Asphalt Mixture's Water Stability

The work environment of asphalt pavement is complex.In recent years,water stability of asphalt mixture in conventional region has been studied by the road workers,but in the harsh environment,research is little.So,in this paper through the theoretical analysis and laboratory tests,the freeze-thaw splitting test has been conducted to study the changing rule of water stability of asphalt mixture in different concentrations salt solution and different polyester fiber content,and that provides the basis for improving service performance of asphalt pavement in salt enrichment area.In this regard,the performance of polyester fiber asphalt mixture is the focus of the study by adding 0,0.1%,0.2%,0.3%of polyester fiber in asphalt mixture to make standard Marshall specimens and they were soak in 0,10%,15%,20%sodium chloride solution,these specimens were used to do freeze-thaw split tests and the freeze-thaw cycles are 0,2,4,6,8.Finally,the splitting test was tested to analyze the mechanical properties and water stability of pavement material in salt erosion and freeze-thaw.The conclusions are as follows:(1)When the concentration of sodium chloride solution and the number of freeze-thaw cycles is constant,the freeze-thaw splitting tensile strength and the freeze-thaw splitting tensile strength ratio of the asphalt mixture were firstly increased and then decreased with the increase of content of polyester fiber.(2)There was a peak value in the process of the improvement of the performance of asphalt mixture of polyester fiber,so,the optimum content of polyester fiber is 0.2%.(3)When the content of polyester fiber and the number of freeze-thaw cycles were constant,with the increase of concentration of sodium chloride solution,the freeze-thaw splitting tensile strength and the freeze-thaw splitting tensile strength ratio of the asphalt mixture were gradually decreased and the water stability of asphalt mixture was weakened gradually.(4)When the influence factors of freeze-thaw cycles was only considered,with the increase of the number of freeze-thaw cycles,the freeze-thaw splitting tensile strength of asphalt mixture was decreased and the water stability of asphalt mixture was weakened gradually.