Test Research Of Influence About Water Stability Of Fiber Asphalt Mixture By Salt

With the rapid development of highway in our country and increasing traffic volume, the early damage phenomenon of asphalt pavement is appearing, such as crack deformation and so on. Especially in the western salt lake region is most obvious where is eroded by salt for a long time. The existing researching for water stability of asphalt mixture under the erosion of salt is less. So the paper uses freeze-thaw splitting test and Marshall test, through combining with theoretical analysis and laboratory tests, research the transformation law about water stability and Marshall mechanical properties of asphalt mixture under the action of different types of salt solution and fiber. The results show that fiber can improve the water stability and Marshall mechanical properties of asphalt mixture in salt enrichment region.The paper studied three kind of fiber (lignin fiber, polyester fiber, basalt fiber) of asphalt mixture through indoor test. Study the transformation law of the mechanical properties and water stability about asphalt mixture under the same fiber content (0.3%), saturated sodium chloride solution (26%) and saturated sodium sulfate solution (16%), the main conclusions are:(1) The Marshall stability and flow value of three kings of asphalt mixture are determined by Marshall test. The results show that the Marshall stability and flow value are bigger than ordinary asphalt mixture.(2) The Marshall stability of asphalt mixture which is soaked in saturated sodium chloride solution and saturated sodium sulfate solution are smaller than that in water. So the Marshall mechanical properties are greatly influenced by the salt.(3) The splitting tensile strength and the freeze-thaw splitting tensile strength ratio are studied by freeze-thaw splitting test. The test results show that the splitting tensile strength and the freeze-thaw splitting tensile strength ratio of asphalt mixture which is soaked in salt solution are smaller than that in water. It illustrates that salt solution can reduce the water stability of asphalt mixture.(4) By contrasting analysis from the splitting tensile strength and the freeze-thaw splitti ng tensile strength ratio of three kinds of asphalt mixture, the water stability of asphalt mi xture which is adding polyester fiber is best than other two fiber asphalt mixture.