紫外光老化后沥青混合料路用性能非线性预测

Nonlinear Prediction of Road Performance of Asphalt Mixture after Ultraviolet Aging

为研究紫外光老化后沥青混合料路用性能衰减规律,运用Verhulst模型建立沥青混合料路用性能的非线性方程,利用Levenberg-Marquardt(LM)算法及最小二乘法分别对非线性方程参数进行估计,并通过不同室内紫外光辐照时间下AC-13和AC-16沥青混合料路用性能试验验证非线性方程的可靠性.结果表明:基于LM算法估计的非线性方程参数比最小二乘法更可靠,相应非线性方程能较准确预测沥青混合料路用性能,低温劈裂强度、动稳定度预测值与试验值最大误差分别为0.35%,7.64%(AC-13沥青混合料)及-0.81%,-11.45%(AC-16沥青混合料).在室内紫外光辐照194h(室外紫外光辐照2 871.2h),沥青混合料路用性能的紫外光老化速率和紫外光老化残余指数降幅明显,随着室内紫外光辐照时间增加,两者逐渐趋于稳定.

In order to study pavement performance deterioration law of asphalt mixture after ultraviolet（UV）aging,the nonlinear equation of road performance of asphalt mixture was established by Verhulst model,and the parameters in the nonlinear equation were estimated by Levenberg-Marquardt（LM）algorithm and the least square method.The reliability of the nonlinear equation was verified through the pavement performance tests of AC-13 and AC-16 asphalt mixture at the different times of UV aging in lab.The results show that the LM algorithm is more reliable than the least square method to estimate the parameters in the nonlinear equation,the nonlinear equation can accurately predict the low temperature splitting strength and dynamic stability of asphalt mixture,the maximum errors between the calculated values and experimental values are 0.35%,7.64%（AC-13 asphalt mixture）and-0.81%,-11.45%（AC-16 asphalt mixture）.The reduction of UV aging rate and UV aging residual index for road performance of asphalt mixture are remarkable after 194 hUV aging in lab（2 871.2hUV aging outside）,and with the increase of UV aging time in lab,the UV aging rate and UV aging residual index tend to stable.