沥青路面层间界面摩阻效应及其对层间抗剪强度影响机理

Frictional-resistance Effect at the Interface Between Asphalt Layers and Its Influence Mechanism on Interlayer Shear Strength

沥青路面层间界面的凹凸体构造和3D形貌影响其摩阻特性,而摩阻特性决定其层间抗剪性能。为了从沥青路面层间界面三维细观特性角度定义其产生的摩阻效应,并揭示其对层间抗剪强度的影响机理。首先,制作不同级配组合复合试件,利用层间界面无损分离、三维激光扫描和逆向重构技术,对上-下结构层间界面进行数字化处理;随后,基于界面形态和构造信息、固体粗糙表面接触理论及复合试件成型特点,定义并计算了层间界面的“接触”与“嵌锁”效应,阐明了层间颗粒物质“接触”、“嵌挤”行为特性与摩阻效应的内在联系;最后,依托1stOpt计算平台的LM-UGO算法及信息熵理论,建立了层间抗剪强度熵权组合预测模型,探明了摩阻效应对层间抗剪强度特性的影响机理。结果表明:含有较多细集料和矿质填料的密级配混合料相互结合时,因比表面积和微细观纹理占优,其摩阻效应更具优势;层间抗剪强度熵权组合预测模型均衡了单一预测模型的优缺点,能较好地以层间“双界面”视角从“接触”和“嵌锁”双维度解释摩阻效应对层间抗剪强度的影响机理;“强嵌锁”时,“嵌锁效应”对层间抗剪强度形成起主导作用,“接触效应”影响被削弱;而“强接触”时,“接触效应”对斜剪强度的贡献较直剪受力时明显增强,“嵌锁效应”被削弱。

The macroscopic and microscopic structures of the three-dimensional interface morphology are intricately linked to the frictional characteristics between asphalt-pavement layers.Interlayer friction properties play a pivotal role in determining the interlayer shear performance.This study explores the relationship between the features of asphalt pavement layer interfaces and the frictional effects from a micro-perspective,unveiling the mechanism of its effect on interlayer shear strength.First,composite specimens were prepared using various aggregate gradations for interlayer combinations.Digitalization of the upper-to-lower structural interlayer interfaces was achieved through non-destructive separation,laser scanning,and reverse reconstruction techniques.Subsequently,relying on interlayer interface morphology characteristics,and based on the principles of solid rough surface contact theory and the characteristics of composite specimen formation,the“contact effect”and“interlocking effect”of interlayer interfaces were defined and computed,elucidating the inherent connection between the behavior characteristics of interlayer particles in terms of“contact”and“interlocking”and the interlayer frictional effect.Finally,leveraging the Levenberg-Marquardt algorithm,the universal global optimization algorithm,and information entropy theory on the 1stOpt computation platform,we established an entropy-weighted combination predictive model for interlayer shear strength based on the frictional effect.This model elucidated the underlying mechanisms through which the interlayer frictional effect influences the characteristics of interlayer shear strength.Results indicate that the three-dimensional morphology of interlayer interfaces and the structure of protrusions and recesses have a direct influence on“contact”and“interlocking”characteristics,consequently affecting the interlayer frictional effect.The entropy-weighted combination predictive model for interlayer shear strength effectively balances the strengths and weaknesses of individual predictive models.This model,viewed from the perspective of interlayer dual-interface,offers a comprehensive explanation of the mechanisms by which the interlayer frictional effect influences interlayer shear strength in both the“contact”and“interlocking”dimensions.