The Study On Asphalt Pavement Structure Of G60 Xiangtan-Shaoyang Highway Heavy Maintenance

As the rapid development of transportation industry in China,the early construction of the highway has used for years,approaching their serve life.The aim of Chinese highway construction will gradually switch from " construction-oriented" to " maintenance and construction-oriented".Therefore,what urgently needed to be solved is how to scientifically choose the large and medium maintenance schemes of highway asphalt pavement as well as how to systematically control the quality in reconstruction project and so on.On the basis of field survey and research engineering data,this paper summarized the types of diseases and causes of asphalt pavement for Xiangtan-Shaoyang section of G60,which provided engineering basis for determining the maintenance schemes.Moreover,it summarized and analyzed the scheme of asphalt pavement in China,and drafted three schemes:overlay asphalt pavement after comprehensive disposal of old pavement,cold recycled asphalt pavement after plant mix,hot recycled asphalt pavement after plant mix.According to the current design specifications,the fatigue cracking of inorganic binder stabilized layer and permanent deformation of asphalt mixture layer of the three schemes are calculated and the cost of the three structural schemes are evaluated,it provides theoretical foundation of pavement heavy maintenance.Establishing the finite element model of asphalt pavement structure with ABAQUS.After verifying the reliability of the model and considering that there are many heavy-loaded on G60 highway,the deformation and failure of asphalt pavement structure under standard load and extremly heavy load are simulated respectively.Based on the analysis of technical and economic benefits,a type of asphalt pavement structure schemes with the most optimum cost in performance is recommended,that is,hot recycled asphalt pavement after plant mix;Marshall design method is utilized to determine the production mix ratio and optimum dosage of RAP of Hot in-Plant Reclaimed Asphalt Mixture,and controling the quality from design,equipment,construction,ect.Finally,the site detection of thickness,compaction,flatness and seepage coefficie in the Tan-shao Highway heavy schemes can verify the feasibility of this structure scheme.Through the study of this subject,the proper asphalt pavement structure scheme,which is suitable for the Tan-shao Highway has been found,which could provide a certain reference and guidance for the design and construction of the highway heavy maintenance in south China,and has a certain practical application value.