The Analysis Of Long Life Asphalt Pavement Fatigue Model And Design Index

With the rapid development of road traffic, early damage of highway asphalt pavement in our country occur frequently, which greatly increasing the cost of maintenance and repair, and the pressure on the economic society. Under this background, the long life asphalt pavement is paid more and more attention, and the idea of the lowest total life cycle cost is also fit for the sustainable development of economy and society. Long life asphalt pavement is a new technology for the international road engineering community, which set the lowest life cycle cost concept ion as the starting point, the biggest feature is in the e ntire life cycle, no damage to the structure occured. Only in certain period maintenance can keep higher performance.Based on the research project of "heavy traffic long life asphalt pavement application technology research" finished by the Communications Research Institute of Liaoning Province. Analyzed the typical long life asphalt pavement structure fatigue model and fatigue design index values in Liaoning Province, aimed at through analysis and calculation, putting forward the values of long-life asphalt pavement fatigue design control index which based on the measured data, laying the applicated foundation for long-life asphalt pavement in our country.Firstly, fitted the fatigue model of asphalt layer and base materials in the structure of long life asphalt pavement, by using the fatigue test data. Then, calculated the transient dynamic response of the layers in long life asphalt pavement, and verified the validity of theoretical calculation by the test data of accelerated loading test. Finally, substituted the strain response into the fatigue model, calculated the fatigue life of each layer. According to the current traffic classification, substituted the critical traffic into fatigue model, calculated the upper limited values of the long life asphalt pavement fatigue designing index at each traffic grade.Through the calculation and analysis, the fatigue life of the subsurface layer is the lowest, and the tension strain is the key to control the fatigue life of the pavement structure. For the specification of the light traffic levels, the proposed fatigue design index control value was 143με; for middle traffic and heavy traffic levels, the proposed fatigue design index control value was 105με and 89με; for the cumulative axis load reaches 1 billion times severe traffic levels, the proposed fatigue design index control value was 65με.