基于Jamming转变理论的沥青路面车辙演化机制

Rutting evolution mechanism of asphalt pavement based on the Jamming transition theory

摘要:

沥青路面宏观车辙其实质是混合料细观结构演变的结果,为了深入理解路面车辙流变行为的发展过程,基于颗粒物质Jamming理论开展了沥青混合料车辙演化机制研究。采用图像处理技术构建了沥青混合料细观结构模型,基于时-温等效原理开展了车辙仿真测试,分析了车辙变形过程中混合料宏细观结构的变化特征,探究了沥青路面Unjamming转变行为的影响规律与车辙演化机制。结果表明:Jamming理论可以很好地解释沥青路面的车辙演变全过程,车辙深度与沥青混合料颗粒的堵塞程度密切相关;随着加载时间和作用荷载的增加,混合料Jamming堵塞程度增大,车辙深度和面积分数也逐渐增加,并最终趋于稳定,颗粒体系Jammed态的转变受到了沥青砂浆和集料骨架共同作用的影响;随着测试温度升高,试件内部颗粒位移和位移差增大,混合料Jamming堵塞程度降低。沥青路面颗粒体系由稳定的Jammed态转变为不稳定的Unjammed态,是诱导路面车辙和泛油病害发生的内因,研究结果实现了Jamming理论在非晶体系中的应用,为深入理解沥青混合料的车辙演变行为提供了一种新的研究思路。

Abstract:

The essence of macro rutting of asphalt pavement is the result of the evolution of the meso-structure of the mixture. To understand the development process of rutting behavior, the evolutionary mechanism of rutting in asphalt mixture was investigated based on the Jamming transition theory of particle materials. The image processing technology was used to construct a meso-structure model of the asphalt mixture. Rutting simulation tests were conducted based on the time-temperature equivalence principle. The macro and micro variations of the mixture structure during rutting deformation were analyzed. The influence of Unjamming behavior in asphalt pavement and the evolution mechanism of rutting were investigated. The results show that the rutting evolution process of the asphalt mixture can be explained well by the Jamming transition theory, in which the depth of rutting is closely related to the jamming degree of the asphalt mixture system. With the increase of loading time and loading force, the Jamming degree of the mixture particle system gradually increases, along with the increase of rut depth and area fraction, and eventually tends to a stable state. The Jammed state of the particle system is affected by the joint action of asphalt mortar and aggregate skeleton. With the increase in the test temperature, the particle displacement and displacement difference inside the specimens increased, and the Jamming blockage degree of mixture particle system decreased. The transition of the asphalt pavement particle system from a stable Jammed state to an unstable Unjammed state is the internal mechanism inducing rutting and oil flooding. This study successfully applied the Jamming theory to an amorphous system, providing a new research method for understanding the rutting evolution behavior of asphalt mixture.