Analysis About Mechanical Response And Structural Combination On Long-life Composite Pavement Under Load Coupling

Structure of semi-rigid asphalt pavement is the main form of urban arterialroads in China, but often appears all sorts of diseases and even serious damage soonafter the projects completed. Because the security operation service period of it isgenerally less than the design life, there is an urgent need to develop the long-lifecomposite pavement. According to the design concept and the functionally gradedmatching principle of the long-life composite pavement, this thesis puts forward anew type of long-life composite pavement structure. In this structure, highperformance cement-emulsified asphalt concrete (CEAC) is used in the high stressarea (binder course), and the large size asphalt macadam and the cement stabilizedgravel are used to combine into a kind of composite base. This can effectivelyreduce the structural damage and functional failures of the existing semi-rigidasphalt pavement, and achieve the long life cycle of road safety operation.The existing analysis methods of the asphalt pavement, elastic layered systemtheory and finite element numerical analysis method are compared in this thesis. Itis considered that the three-dimensional finite element model has the betterperformance of the mechanical state of the pavement structure under load. Thethesis also researches and puts forward the design control indexes about stiffnessreserve and strength reserve of long-life composite pavement, preliminary studiesthe long-life composite pavement about the functional and technical and economicdesign models and processes.Based on the three-dimensional finite element model, the thesis analyzes theeffect to the long-life composite pavement of the mechanical parameter (elasticmodulus) of pavement material and the thickness of each layer. The thesis also putsforward the material and thickness of each layer of Yichang long-life compositepavement through the combination of theory and practice. The result shows that thelong-life composite pavement is better than the usual semi-rigid asphalt pavement.Further coupled vehicle load and temperature load on the long-life compositepavement, the research gets the typical curve of temperature field in summer of thelong-life composite pavement, and analyzes the effect of vehicles-temperature coupling stress field on the long-life composite pavement in detail. The thesis alsoconsiders the effect of overload, slope and other complex situations for the long-lifecomposite pavement.Based on the macroscopic mechanical analysis of the long-life compositepavement, the thesis selects the key material of this structure, cement-emulsifiedasphalt concrete, to analyze its material impact mechanism in the meso-scale, andcompare its macro and meso scale stress (strain) field distribution and failuremechanism. The results show that the stress and destruction form ofcement-emulsified asphalt concrete in the meso-scale is different from that in themacro-scale. With the meso-scale analysis of pavement materials on the basis of themacro-scale analysis, it can be a deeper understanding of the local stress (strain)distribution of the pavement structure, and promote the reasonable design ofpavement materials.