Study On Pavement Performance Of Repairing Longitudinal Joints Of Jointed Asphalt Pavement By Polymer Grouting

Splicing asphalt pavement is an effective reconstruction and expansion method to improve the pavement capacity,which is widely used in practical projects.However,the spliced asphalt pavement is prone to uneven settlement of soil foundation under the long-term action of vehicle load,which reduces the structural bearing capacity of the road,leads to longitudinal cracks at the splice,and affects the driving comfort and safety.Polymer grouting technology is a new type of pavement longitudinal joint treatment technology,which can treat the longitudinal crack disease of spliced asphalt pavement.It has been widely used in engineering.However,the stress response and fatigue life of spliced asphalt pavement repaired by polymer grouting under traffic load are still lack of theoretical research.Through the combination of field investigation,model test and numerical simulation,this paper studies the road performance of polymer grouting repair of spliced asphalt pavement.The main contents and results are as follows:(1)The compressive strength test and tensile strength test of polymer materials are carried out,and the correlation between tensile strength,compressive strength and density of polymer materials is established.The results show that the tensile strength and compressive strength of polymer materials have a positive linear correlation with polymer grouting density.Increasing grouting density can effectively improve the tensile strength and compressive strength of polymer materials.(2)The splitting strength test of rutting board polymer composite and the shear strength test of cement stabilized macadam polymer composite were carried out,and the splitting strength equation and shear strength equation of the composite were established.The bending strength test and fatigue test of rutting plate polymer composite were carried out,and the fatigue life equation of the composite was established.The results show that the splitting strength of rutting plate polymer composite increases with the increase of grouting density and bonding surface roughness;The shear strength of cement stabilized macadam polymer composite increases with the increase of grouting density and bonding surface roughness;The fatigue life of rutting plate polymer composite increases with the increase of grouting density and decreases with the increase of stress level.(3)Based on the elastic layered system,the dynamic response of spliced asphalt pavement is analyzed.The results show that the Mises value of the longitudinal crack position of the spliced pavement decreases by 40-70%after polymer grouting;Compared with the pavement damaged by longitudinal joints,the stress value and vertical displacement of spliced asphalt pavement repaired by polymer grouting are smaller;When there is a slight longitudinal joint in the spliced asphalt pavement,the grouting treatment shall be carried out in time.At this time,the pavement performance recovers best after the pavement treatment;When the load is 0.7MPa standard axle load,the fatigue life of spliced asphalt pavement after longitudinal joint repair can reach 8×10~8 times.The results show that the road performance of spliced asphalt pavement has been effectively improved after grouting repair.