Analysis Of Semi-rigid Base Asphalt Pavement Diseases And Prevention Research

Semi-rigid base asphalt pavement has high strength, good stability, good board member and economical advantages, so it is still the main structure form of the highway in our country. But semi-rigid base inevitably produce dry shrinkage and temperature shrinkage crack, the crack of semi-rigid base gradually expand to the surface to form reflective cracks under cyclic loading and temperature effects, and along with the extreme weather, the growth of heavy traffic, overloading phenomenon reflective crack is more and more serious, then induce slurry pump, loosening at the grass-roots level, subsidence and other diseases. At the same time asphalt mixture is a typical viscoelastic material, which is highly sensitive to temperature and its property changes with temperature changes. Asphalt layer occurs vertical permanent deformation accumulating rut disease under the cyclic vehicle load, and rutting seriously affect the smoothness and driving comfort of the pavement, even threaten the traffic safety. Therefore, under the condition of extreme weather and heavy traffic,the development rule and influence factors of semi rigid base asphalt pavement reflection crack and rut disease are studied, and put forward the corresponding countermeasures has important significance.First of all, this paper base on the linear elastic fracture mechanics, and establish a two-dimensional finite element model to simulate semi-rigid base asphalt pavement, and carry out mechanical response analysis of asphalt pavement including cracked base under vehicle load and temperature load. The driving load is divided into two load modes containing the traffic load is applied symmetrically on the top and applied on the side of the cracks, and analyze the change rule of stress and stress intensity factor near the crack tip, and analyze the structural parameter sensitivity of stress and stress intensity factor near the crack tip. Considering a sudden drop in temperature at the same time, analyze the structural parameter sensitivity of stress andstress intensity factor near the crack tip. On this basis, the primary control measures of reflection crack are discussed.Secondly, two-dimensional finite element model of pavement structure is established based on viscoelastic theory, and analyze the forming regularity and influence factors(temperature, axle load, vehicle velocity and thickness of asphalt surface, etc.) of the rutting of semi rigid base asphalt pavement. On this basis, the primary control measures of the rutting of asphalt pavement are discussed.Finally, in the case of the disease treatment of zhumadian to xinyang of Beijing Hong Kong and Macao highway, discuss the treatment scheme of two kinds of diseases of reflection crack and rut, and main problems in the process of the disease treatment. And guarantee the quality of the disease treatment of asphalt pavement to achieve good control effect.