热夹层条件下沥青路面温度梯度分布特征研究

Study on temperature gradient characteristics of asphalt pavement including thermal interlayer

为探讨热夹层条件下沥青路面温度梯度变化与外界环境因素之间的相关关系,采用三维有限元数值计算方法,分析了不同热夹层条件、路表环境温度及对流系数下沥青路面结构温度场的空间分布规律,构建了外界环境参数、热夹层温度与热稳态路表温度的对应数据库,并基于多元线性回归分析方法,建立了沥青路面热夹层温度预估分析模型.结果表明:无热夹层条件下道路表面环境温度是影响路表热稳态温度的主要因素,对流系数的变化对沥青路面温度场空间分布几乎没有影响;有热夹层条件下路表热稳态温度随路表环境温度的下降而降低,且对流系数的增大对路表热稳态温度的下降速度有推动作用;所构建的沥青路面热夹层温度预估模型具有高度显著性,模型系数的置信概率较高,热夹层温度预测值与理论值之间误差较小,模型精度良好.研究成果为低温地区结冰路面热夹层温度控制提供了理论依据.

In order to investigate the relation between the temperature gradient of asphalt pavement with a thermal interlayer and environmental factors, a series of factors including thermal interlayer temperature, ambient temperature and convection coefficient were chose to explore the distribution characteristics of asphalt pavement temperature field on the basis of the three-dimensional finite element analysis method, and to establish a corresponding database, which was utilized to set up a temperature prediction model of the thermal interlayer by the multiple linear regression analysis. The results indicated that the ambient temperature was the main factor influencing the pavement surface steady-state temperature and the change of convection coefficient had little impact on the asphalt pavement temperature field spatial distribution for the non-thermal interlayer condition. The pavement surface steady-state temperature decreased with the decline of ambient temperature, and the increasing of convection coefficient could accelerate the temperature decreasing rate for the thermal interlayer condition. The temperature field prediction model was in good agreement with experimental values, the validity of the model was also verified. The research could provide technical basis for controlling the thermal interlayer temperature for deicing or snow-melting of asphalt pavements located in the low temperature region.