The Study On Application Of Hot In-place Recycling Technology In Maintenance Of Zhejiang Expressway

During the long-term use of asphalt pavement,through the traffic load and the role of natural factors,gradually aging,hardened,resulting in asphalt pavement cracks,potholes,loose and other damage.Therefore,after a certain number of years,the asphalt pavement must be subjected to large and medium repair.With the maintenance of asphalt pavement and the increase of large and medium repair works,a large number of waste asphalt mixture has been produced,and the stacking of waste materials has caused great damage to the environment.Therefore,it is necessary to study the application of asphalt pavement recycling technology.Asphalt pavement recycling technology is a new kind of high grade pavement maintenance technology,through local heating,loose,mixing,paving,compaction and.continuous operation,forming a new road,is currently used in high grade pavement maintenance engineering in China is more and more widely.Based on the geothermal recycling project of Zhejiang Shanghai Hangzhou Ningbo Expressway,this paper mainly studies the application of geothermal recycling technology in Shanghai Hangzhou high-speed maintenance project:First of all,based on the evaluation of the performance of the old asphalt pavement,the gradation design and performance test of the thermal recycled mixture were completed in the room.The results show that the pavement diseases are dominated by massive cracks and cracks,accounting for more than half of the pavement diseases.The old asphalt pavement bearing capacity can basically meet the requirements of high temperature stability;old asphalt mixture gradually increased,the low temperature performance decreased,water stability decreased;two little difference between the high temperature stability of mixed recycled material gradation design,low temperature crack resistance of two is slightly better,the water stability and gradation were similar.A slightly better,the grading as gradation design of construction site.Secondly,combined with the project,the preparation,construction,transportation,paving,rolling and regeneration quality control of the Shanghai Hangzhou Ningbo Expressway are studied.Finally,the construction quality is analyzed and evaluated.The test results of construction quality are analyzed statistically,including smoothness,skid resistance and seepage parameter test.The technical and economic effects,social and environmental effects of geothermal reclamation construction are analyzed.The results showed that the international roughness index,IRI,coefficient of friction coefficient,average value of pavement structure depth and water permeability coefficient were all improved in different degree.The regeneration of the posterior surface roughness of mean,standard deviation and variation coefficient were decreased;the Sideway Force Coefficient mean increased to more than 50,the anti slide performance enhancement;structural depth increased,the coefficient of variation decreased;average permeability coefficient increased,reducing the standard deviation and variation coefficient.The implementation of this project has promoted the application of geothermal regeneration technology in the maintenance of expressways in Zhejiang Province,showing its broad application prospects.