Study On Fatigue Performance Of Asphalt Pavement In Highly Cold Region Based On Accelerated Loading Test

Asphalt pavement is widely used in high-grade pavement because of its flat surface,no joint,driving comfort and other advantages,but it is easy to be affected by climate and load and other factors,resulting in performance degradation.The cold regions in northern China have long winters and a cold and dry climate.As a result of the extreme environment and long-term traffic load,asphalt pavements are prone to hardening and fatigue damage,which in turn leads to a significant reduction in the structural life of asphalt pavements in cold regions.This paper is supported by the Inner Mongolia Transportation Science and Technology Project: "Fatigue Performance Research on Asphalt Pavement of High-grade Highways in Cold Regions Based on Accelerated Loading(NJ-2015-37)".The fatigue performance of asphalt pavement in the section was studied,and the fatigue damage and evolution of asphalt pavement in highly cold region were systematically analyzed,and the design of asphalt pavement materials and structures in the area was optimized.This thesis relies on the key pavement structure and materials laboratory of Colleges and universities in Shandong Province,and uses the small-scale rotary accelerated loading test system(ALT-R100)independently developed by our school to carry out full-scale accelerated loading test of asphalt pavement in cold areas.In the test,a full scale test section of a typical asphalt pavement in a cold area was paved,and various sensors and wires were synchronously embedded to establish a full-scale pavement structure model;On the basis of the pavement structure model,the use of a small rotary acceleration loading test system is true and reasonable The effect of simulated vehicle load and cold environment on the fatigue damage of the road surface.During the test,the strain sensor embedded in the road base layer is used to collect the sub tensile strain of the road base,and the dynamic response of different asphalt pavement structure combinations under the coupling action of load and low temperature is analyzed.The performance of asphalt pavement was tested by pendulum friction meter and rut detection instrument,etc.,and the evolution rule of asphalt pavement performance with the number of load actions was studied.Combined with fullscale accelerated loading test,indoor material test and theoretical analysis,the damage mode of asphalt pavement under the combined action of dynamic load and temperature environment factors is revealed,and the evolution rule of fatigue performance of asphalt pavement structure model under the coupling action of high cold and dynamic load is established.The research results of this paper can provide experimental basis for the structural design and material composition of typical asphalt pavement in Inner Mongolia cold region,as well as theoretical and decision-making support for asphalt pavement life prediction,maintenance and repair scheme formulation.