Service Life Analysis Of Old Asphalt Pavement After Overlay Based On Different Treatment Technology Of Interlayers

In recent years,with the continuous increase of the total mileage of highway construction in China,the total mileage of highway maintenance has also increased year by year.It has been proved that if we repaired the old pavement without true evaluation.Some problems will appear,such as inadequate treatment of the original surface layer of the old road,inadequate treatment of the interlayer connection.As a result,some domestic highway asphalt pavement will appear early disease soon after opening to traffic,and it has to be repaired in advance when the pavement disease is not serious.Therefore,according to the actual situation of asphalt pavement in Liaoning Province,we carry out indoor test,field investigation and corresponding theoretical analysis.Finally,the paper analyzes the fatigue life of asphalt pavement after functional repair and structural repair under different base conditions and different interlayer treatment technologies,so as to provide guidance for the future scientific and reasonable asphalt pavement repair project.First of all,in order to evaluate the interlayer connection effect of different interlayer treatment technologies,indoor direct shear test was carried out,including functional repair(interlayer treatment technology between the overlay and the old road surface)and structural repair(interlayer treatment technology between the cement stabilized macadam base and the asphalt mixture surface).By changing the normal stress acting on the test piece,the shear strength of the test piece under different normal stress is obtained,so as to obtain the relationship between the normal stress and the shear strength,and the interlayer friction coefficient of the pavement structure under different interlayer treatment technology.Secondly,we investigate the key routes of interlayer treatment technology in Liaoning Province,and record the route name,location,maintenance history,types of interlayer treatment technology and pavement diseases.In order to establish the relationship between the pavement diseases and the technical conditions of the base course,we drill core samples at different diseases,study the technical conditions of the base course,analyze the common diseases of the asphalt pavement of the ordinary highway and grade the obtained core samples.Thirdly,we evaluate the technical condition of asphalt pavement of ordinary highway,mainly the technical condition of basic level.The evaluation index of basic level technical condition and BCI of basic level damage condition are put forward,and the calculation method of BCI is given.We test the resilient modulus of the core base in the laboratory,and get the average modulus of the core base under different BCI,finally establish the relationship between the dynamic modulus of the base and the BCI.Finally,aiming at the pavement structure model of functional repair(surface milling and resurfacing)and structural repair(asphalt surface milling and resurfacing),we use ABAQUS finite element software to calculate the fatigue life of pavement structure after resurfacing in different base technology conditions and different interlayer treatment technology,and coMPare the theoretical calculation analysis with the field investigation results,which proves reliability of theoretical analysis.