The Research Of Cold Recycled Mixture And Application In Northwest’s Roads

In this paper,after fully analyzing the research status of cold regeneration technology of asphalt pavement at home and abroad,relying on the project of "Cold with Asphalt Regenerator" in the construction industry of the Ministry of Housing and Urban Construction,this paper takes the S201 shuping section of Gansu Province and the honggu section of Lanzhou G109 Maintenance of the renovation project as the research object,to re-study the higher content of RAP mix of recycled materials and pavement structure of the new type,the specific research as follows:(1)To investigate and analyze the geographical environment,climatic conditions,the original pavement structure,traffic volume,historical maintenance and common diseases of trunk roads in Gansu Province,and summarize the causes of common diseases.For the S201 shuping section and Lanzhou G109 honggu section Pavement deflection analysis and damage assessment,according to the road survey results and disease conditions to determine the thickness of pavement structure regeneration layer,and then put forward pavement structure maintenance program(2)Review the literature,summarize the design method of cold reclaimed mixture at home and abroad,determine the research methods and design steps of the recycled mixture in this paper.The RAP grade and the asphalt waste performance of the original pavement material were tested to improve the RAP content,The new aggregate gradation is redesigned according to the "S-type" gradation curve;the optimum cement dosage in the regeneration mixture is determined,and the emulsified asphalt cultivars with better performance are selected and compared with the comparative test.The test conditions were used to determine the properties of the regenerated mixture,such as high temperature stability,low temperature crack resistance,water stability and shrinkage.(3)Review the literature,summarize the design method of pavement structure at home and abroad,put forward the new design of cold recirculation pavement structure and the new type of pavement structure.The design index is re-determined for the different damage forms of the road structure and the axle load of different design indexes,Determine the allowable values for different design indicators;(4)Study the elastic fracture mechanics model and the crack type,and deduce the stress intensity factor formula.The pavement structure model is established by using the finite element analysis software ABAQUS to analyze the settlement deformation and stress strain of the pavement structure under the vehicle load.The fractures of the model are analyzed under the partial load and the symmetrical load,and the strength factor of the crack tip under two kinds of loads is calculated to estimate the fatigue life of the pavement structure.(5)Taking the S201 shuping section of Gansu Province and Lanzhou G109 honggu pavement structure maintenance and renovation project as the research object,the application research of regenerative mixture was carried out to verify the performance of the recycled mixture in the construction process.The process of observation of the mixture of the state of the material and the state of the pavement,summed up the pavement process to control the key links and precautions.