Analysis On Permanent Deformation Of Flexible-base Asphalt Pavement

Semi-rigid base asphalt pavement has more reflective cracks, and easily produces pavement rutting and other early damages due to the high base stiffness. The flexible base asphalt pavement permanent deformation is studied in the project based on the natural conditions in Zhengzhou, Henan Province. Some problems caused by unreasonable pavement structure and type, such as the large deformation, easy damage, etc. are solved. It can make high-grade asphalt pavement structure reasonable, economic durable, safe and reliable. Thus, the study on flexible asphalt pavement permanent deformation in Henan Province has important practical significance and theoretical value.In this project, the asphalt pavement of flexible graded macadam base is systematically studied through the survey, the laboratory tests, and the theoretical analysis. The bearing capacity, the structural performance, the pavement performance and the permanent deformation are analyzed in depth. The main originality innovations are as the following:① Through the systematic laboratory test and the tube experiment, the non-linear bearing capacity of flexible graded macadam base is analyzed in depth and the LH non-linear bearing capacity model E= (a+bσ1)σ3+C is proposed, which can more accurately describe the bearing characteristic of flexible graded macadam base.② The non-linear structural analysis method of flexible base asphalt pavement is proposed and the non-linear structural analysis of flexible graded macadam base is carried out. The iterative calculation method in finite element analysis of pavement structure is proposed and used to determine flexible graded macadam base resilient modulus of each point. It can more correctly describe the non-linear features of graded macadam.③ According to the superposition principle of different temperature and different stress, the asphalt pavement permanent deformation (rutting) is calculated. The results show that the flexible graded gravel asphalt pavement has a good anti-rutting ability. In the same pavement structure thickness, the rutting of flexible graded gravel asphalt pavement is about 11% smaller than the rutting of the semi-rigid base asphalt pavement.The project researches have a very important practical guide for highway construction in Henan Province, which will promote the development of high-grade asphalt pavement construction technology and make the pavement structure more reasonable, more economical and better durable.