Application Of High Volume RAP In Thermal Regeneration Technology Of Asphalt Pavement

In recent years,with the public's awareness of energy conservation and environmental protection,road industry workers have carried out many researches on recycled mixture experiments,and various types of regeneration technologies have been rapidly developed.As a renewable resource,reclaimed asphalt pavement?RAP?has been gradually taken into account and widely used in new road construction projects.The existing problems mainly focused on percentage of RAP in the recycled mixture.The low-mixing rate of recycled materials in the regeneration process is not economical.Domestic and foreign experts and scholars have less research on the practical application of high-volume RAP,lack of corresponding theoretical technical support.This paper has carried out the test of high blending ratio recycled materials.The main work is as follows:1?Independently developed a rejuvenated agent about RAP and studied the properties of the rejuvenated agent.We carried out research work on the rejuvenated agent,and prepared corresponding aged asphalt.We tested the recovery effect of asphalt penetration,ductility,softening point and viscosity index,and researched rheological properties by dynamic shear rheometer?DSR?.In this paper,the rutting factor was used to evaluate the high-temperature performance of the reclaimed asphalt,and a parameter“N_{f 50}”was introduced to evaluate the fatigue performance of the reclaimed asphalt;and the aging resistance was evaluated.Through the analysis of various test results,the regeneration effect of this rejuvenated agent is obvious,and the optimal dosage and regeneration efficiency of asphalt regenerant are comprehensively obtained.2?Combined with the regeneration performance of regenerant,a design method of reclaimed asphalt mixture was proposed,which optimized the design process and simplified the test process.On the design idea of the asphalt mixture,based on the regeneration efficiency of the rejuvenated agent,the dosage of new asphalt and the blending ratio of the recycled materials were corrected.Three kinds of recycled asphalt mixtures with 65%,75%and 85%RAP content were designed.The viscosity-temperature curve of the reclaimed asphalt was made to determine the construction temperature of the reclaimed asphalt mixture;and the regeneration process was improved accordingly.The Marshall test determined the optimum ratio of the oil to the three mixtures.The road performance tests of the three RAP blended asphalt mixtures meet the requirements of the specification.3?The warm mixing technology was introduced during the regeneration process,and the combination of the two technologies was realized.The road performance of the warm mix and hot mix recycled asphalt mixture with the same RAP content was compared.In this paper,we used two different warm mixing agents,Sasobit and Defuron.Under the condition of lowering the working temperature of 25?,Sasobit has a positive effect on high temperature performance,and Defuron improves the water stability of the asphalt mixture.Although other road performance slightly lower than hot asphalt mixture,but all properties meet the specifications.Therefore,the combination of high-volume RAP regeneration technology and warm mixing technology is feasible.