Study On The High-temperature Performance Of Asphalt Pavement With Grid

In recent years, during the unprecedented rapid growth of China’s high-grade highways, the road traffic increased significantly, showing the status of larger vehicle load, higher speed etc., caused by which the high temperature rutting of asphalt pavement has led to more attention and concern. In this paper, a series of tests was designed and performed utilizing the characteristics of grid from new way, and the results showed that the lateral flow of aggregates in the asphalt concrete with grid was restricted, main stress in the pavement presented uniform distribution. This improved the effect of road force structure and performance of asphalt mixture under high temperature.First, the mechanical property of laminated graded crushed stone with grid was studied, including to the stiffness modulus and stress carrying capacity. The results showed that the stiffness modulus reached12.06MPa, and stress load reached20MPa. This indicates that in the case of no asphalt, the grid in the laminated graded crushed stone has an effect of restricting the lateral flow of aggregates.Secondly, the mechanical properties of asphalt mixture with grid were studied under high-temperature conditions, including the elastic modulus, rutting and dynamic modulus test. In the elastic modulus test, the elastic modulus of70#+2was the highest in all specimens under the conditions of45℃and60℃respectively, which was1.5594MPa at45℃and1.0546MPa at60℃. This shows that the grid in the asphalt mixture restricts the lateral flow of aggregates and improves the elastic modulus of the whole specimen. In rutting test, the values of do/d1/d2/DS of specimen with grid were0.63(mm)/0.89(mm)/0.96(mm)/8750(times/mm), compared with1.19(mm)/1.68(mm)/1.58(mm)/6462(times/mm) in specimen without grid. This shows the grid, with which asphalt concrete reinforced, changes the force structure and reduced the road surface deformation and increased dynamic stability of asphalt concrete. This can improve the resistance to rutting deformation of asphalt pavement. In dynamic modulus test, the grid in reinforced asphalt concrete improved the dynamic modulus and reduced the phase angle, which can be obtain from the dynamic modulus master curve at the low-frequency/high-temperature side. While, at the room temperature side of the main curve, the grid did not affect its dynamic modulus and phase angle. All of the above results show that the lateral flow of aggregates in the asphalt concrete reinforced with grid was restricted, the main stress in the pavement presented uniform distribution. Grid can make up for the decreased flow restriction force because of the weakened asphalt bond strength under high temperature condition and improve the high temperature stability of the pavement.Finally, performance of asphalt pavement reinforced with grid was studied by the constitutive equation of creep model in ABAQUS finite element simulation software. The results show that the grid can slightly reduce the Pavement Deflection, reducing non-uniform stress distribution in road layers and improve the service life of the asphalt pavement under the same creep deformation and stress.In short, the grid in the asphalt pavement has an effect of restricting the lateral flow of aggregates, and promotes the uniform distribution of main stress in the pavement under high temperature. Road force structure, high-temperature stability, performance and service life of asphalt mixture was improved in the asphalt pavement reinforced with grid. In addition, the increase of costs of using grid is only5%of the modified asphalt. Social and economic significance would be looked forward to by this research.