Analysis on longitudinal cracking of flexible base asphalt pavement undernonuniform distributed tire pressure(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2019年02期
- Page:
- 35-46
- Research Field:
- 道路工程
- Publishing date:
Info
- Title:
- Analysis on longitudinal cracking of flexible base asphalt pavement undernonuniform distributed tire pressure
- Author(s):
- YE Yali1; XU Quanliang2; NING Xuanjie2; YU Sixin3
- (1. School of Transportation and Civil Engineering, Shandong Jiaotong University, Jinan 250357, Shandong, China;〖JP〗2. RIOH Transport Consultants Ltd., Beijing 100191, China; 3. Qilu TransportationDevelopment Group, Co., Ltd., Jinan 250102, Shandong, China)
- Keywords:
- road engineering; accelerated loading failure test; nonuniform distributed strip tire load; maximum shear stress; tire tread pattern; prediction model; crack propagation
- PACS:
- -
- DOI:
- -
- Abstract:
- To study the mechanism of longitudinal cracks in asphalt pavement with a flexible base course and the law of crack development, the grounding impression and stress of truck tires under different axle loads and tire pressures were measured.With the help of the measured tire grounding area and simplified nonuniform distributed contact stress from the radial tires, a mechanical calculation model of tirepavement under a nonuniform distributed strip load was established. A 3D finite element analysis was developed for flexible base asphalt pavement structures with different asphalt layer thicknesses. Through the analysis, the maximum tensile stress and maximum shear stress and their acting positions on the two pavement structures were calculated under the overload conditions and the designed axle load conditions. An accelerated loading failure test was also conducted on a fullscale test road of graded crushed stone base asphalt pavement to obtain the type, location and development law of asphalt layer cracks in medium and lowtemperature environments. The maximum shear stress at the gap between the patterned ribs of the tire tread was proposed as the mechanical index of the topdown cracking of asphalt pavement. Then, based on the mechanical analysis and fatigue failure times of the test road, a topdown fatigue cracking prediction model of asphalt pavement was established. The results show that the maximum tensile stress of flexible base asphalt pavement is far away from the wheel track zone, and its value is far less than the allowable tensile stress of asphalt mixture, which has no effect on the topdown longitudinal cracks. The maximum horizontal shear stress occurs on the pavement surface or within a certain depth from the pavement surface, and the greater the axle load, the closer the maximum shear stress. In addition, the greater the horizontal force, the closer the maximum shear stress is to the center of the wheel bottom, and when the coefficient of horizontal force increases from 0 to 0.5, the maximum shear stress moves from the edge of the wheel bottom to the gap between the second and third patterned ribs of the radial tire. During the accelerated loading failure test with a heavy axle load on the fullscale test road, the flexible base asphalt pavement first has short topdown longitudinal cracks originating from the pavement surface. With the action of the wheel load, these short cracks are connected to each other and are located at the center of the bottom of the wheel. In addition, the direction of their propagation is consistent with that of the patterned ribs, which supports the theoretical analysis results, and indicating that longitudinal cracking originates from the gap between the patterned ribs of the bottom of the wheel. 8 tabs, 21 figs, 28 refs.
Last Update: 2019-04-01