The Research On Mix Design And Pavement Performance Of Hot Mix Thin Overlay

After servicing for many years,the structure of the pavement is intact,but there are many functional diseases,such as lower smoothness,less sliding resistance and high noise.The key to solve this problem is to improve the function of pavement.It is the best strategy to solve such problems by using thin-layer overlay AC-5.However,there are few relevant research data on hot-mix thin-layer overlay AC-5,which causes the design method of thin-layer overlay AC-5 suitable for our country's climatic condition and traffic load is badly lacking.Therefore,it has great importance in engineering value and social significance to research on the design method of thin-layer overlay AC-5 and pave the successful test road.According to the related research and successful experience,the technical performance requirements of thin-layer overlay AC-5 are proposed in view of functional diseases of pavements,surface.By using Marshall test,rut test,low temperature bending test,water seepage test,fatigue life test,structural depth test and immersion fly test,the AC-5 of thin layer overlay is studied in detail,and the test results show that:when the design void ratio reaches 8%,the performance index of the thin-layer overlay AC-5 asphalt mixture can still meet the standard requirements.The gradation range of AC-5 is studied by using the design method of dividing line,and the gradation range of AC-5 is obtained,which can not only satisfy the functional requirement of road surface,but also consider to other pavement performance of asphalt mixture.Based on four aspects of gradation range,optimum oil asphalt,volume parameter and road performance,three kinds of asphalt mixtures,such as thin layer AC-5,SMA-5 and Thus-12,are compared and analyzed.The results show that the thin layer AC-5 is suitable for the area with low temperature,moderate rainfall and large traffic flow.In order to verify the application effect of the thin layer overlay AC-5,the test section was paved in the G354 Nanxing line of Yichun City,Jiangxi Province,which has good road performance after servicing for six months.