Remaining Life Prediction Of Asphalt Pavement Based On Roughness

Pavement roughness is the main reason for dynamic load of the vehicle. Undergoing the pavement roughness excitation, the dynamic load that is different the static load is generated. Affected by the dynamic load, the corresponding response of the pavement will be caused and it accelerates the pavement evenness decay. The worsened roughness further increases the additional dynamic load between the wheels and the pavement. Therefore, there is coupling effect between the pavement roughness and the dynamic load of the vehicle. Based on the coupling effect, the dynamic load and the change of the high-grade asphalt pavement roughness affected by the dynamic load were analyzed through indoor tests, theoretical analysis and model simulation. The dynamic load and the permanent deformation of different pavement points were calculated at different service time and the pavement roughnesses of different service time were obtained. According to the critical roughness or permanent deformation limit, the remaining life of asphalt pavement was achieved, which can provide the basis and reference for pavement management and decision optimization. The Major research results are:(1)Based on the M.W.Sayers theory and the measured results of pavement roughness, the sine wave pavement model is founded; the transforming relationships of pavement roughness between time domain and space domain, amplitude domain and frequency domain are obtained; The relation functions between the pavement power spectrums and the state parameters (wavelength & amplitude), the pavement power spectrum and the standard deviation are achieved,’the velocity is an important link parameter of pavement roughness between the time domain and the space domain’ and ’there is quantitative relation between the standard deviation of pavement roughness and the pavement state parameters’ are exposited.(2) The vehicle-pavement coupling model is established.The dynamic load caused by pavement roughness is analyzed and solved, and systematically study the dynamic load influence laws affected by the pavement state parameters (wavelength & amplitude), speed, load and tire pressure and so on. The results show that the dynamic load increases with the pavement amplitude increase, and there is coupling interrelation between the pavement wavelength and the vehicle speed; the destructive effect on pavement of the dynamic load of empty vehicle can not be neglected and the high pressure of vehicle tire also accelerate the pavement damage.(3)Based on the modified Burgers model, the viscoelastic constructive model of asphalt mixture is established, which can reflect the effect of repeated vehicles loading. The test method of triaxial repeated load creep test is proposed to study the high temperature anti-deformation property of asphalt mixture. A complete specimen preparation method, test equipment requirements, test boundary conditions, temperature conditions, load conditions and others parameters are recommended. By the indoor test, the rheology change of asphalt mixture influenced by the deviatoric stress and the temperature are systematically researched.(4)Using the Levenberg-Marguardt nonlinear least square method and the spline interpolation, the test results of triaxial repeated load permanent deformation are interpolated and fitted. The high precision regression results are obtained and three-dimensional surface of "cycles-partial stress-permanent deformation" under different conditions are obtained. The remaining permanent deformation predictions under lack of experimental data are achieved.(5) Based on the superposition principle, the permanent deformation prediction method of asphalt pavement affected by the vehicle load, material properties and temperature condition is proposed. Combined with the mechanical analysis and the permanent deformation model, the corresponding prediction flow and steps are proposed, which can provide a reference for asphalt pavement design and permanent deformation ’prediction research of asphalt pavement.(6)A new method of the remaining life prediction and service performance of asphalt pavement is proposed. Taking the K15～K6 section of Qijiang-Wansheng highway as example, the dynamic load caused by pavement roughness and the partial stressed in pavement structure layers caused by the dynamic load are calculated. Given the pavement material properties under different test conditions in the triaxial repeated load, the numbers of standard axle loads in the different representative temperature ranges are analyzed. Finally, the pavement roughness model and the remaining life prediction model of Qijiang-Wansheng highway are established, which can more accurately predict the remaining service life of asphalt concrete pavement and provide the basis for the scientific pavement management and decision.