Study On The Fatigue Character Of Asphalt Treated Permeable Material In Asphalt Pavement

In recent years, people realize the importance of road drainage system because of more and more water damage. Meanwhile, the great stability and good capability of resisting on fatigue make asphalt-treated base the first place in the structure of long-life pavement. Then, more attentions are paid to asphalt-treated permeable base (ATPB). ATPB, however, has a poor fatigue-resist character because of its high air-void (usually more than 15%). The problem that we are facing now is how to deal with the high void and poor fatigue-resist character and find a balance point between them. So, it is necessary to study on the impacts of ATPB fatigue-resist performance. And it will be a reference to the design method of this kind of material.This paper studies the mechanism of fatigue cracking of asphalt mixture and it mainly focuses on ATPB. And some measures are suggested to improve the fatigue-resist performance. The impacts of main pavement structure parameters on mechanics response of ATPB are studied according to elastic-layered system theory and orthogonal analysis method. Then, the unwelcome pavement structure which should be avoided in pavement design is proposed. Lab studies are taken to research the factors that impact the ATPB fatigue-resist performance. In addition, the fatigue equation of ATPB is gotten by strain-controlled fatigue experiment. Meanwhile, fatigue equations of several materials are compared.According to elastic-layered system theory and orthogonal analysis method, the key factor that influences the stress and strain on the bottom of ATPB is module of layer below ATPB. The structure which has the great strength base and thick course will prevent fatigue cracking. According to the experiment, air-void has effects on ATPB fatigue-resist performance. In this paper ATPB-20 is studied. According to the experiment it is recommended that the 4.75mm percentage should be 20%, the larger filler to bituminous ratio is the poor fatigue-resist performance will be and fiber have some positive effects on ATPB fatigue-resist performance. Compared with several fatigue eqution, ATPB has greater capacity of resistence on overload than cement treated permeable base (CTPB) when they have the same design life.