ABSTRACT

This article is related to the development of potholes in bituminous pavements possibly occurring in winter at negative temperature and in presence of pore water in the asphalt concrete (AC) layers. It was shown already that this type of degradation could be due to swelling of the AC pore water. A constitutive law was previously developed to model this phenomenon; the present article deals with its implementation in a finite element (FE) program to evaluate the mechanical effects induced by the propagation of a frost front in a pavement. This novel program handles the coupling between the thermoviscoelastic problem with swelling in AC materials and the heat equation with phase change. First applied to the modelling of characterization tests on partially saturated AC specimens, the developed program has proved to be relevant. Then, to get closer to onsite conditions, an original frost-thaw test was carried out on a bilayer AC structure partially saturated. The test led to the delamination of the two layers during the second frost-thaw cycle. Its modelling showed that the interface rupture was triggered by differential strains and self-stress fields developing in the sample. These results can provide an explanation to the initialisation of the pothole issue.

摘要

这篇文章是关于在冬季负温度和沥青混凝土 (AC) 层中存在孔隙水时可能发生的沥青路面坑洼的发展。已经表明，这种类型的降解可能是由于 AC 孔隙水的膨胀。以前制定了本构法来模拟这种现象。本文介绍了它在有限元 (FE) 程序中的实施，以评估由路面中霜锋传播引起的机械效应。这个新颖的程序处理了 AC 材料膨胀的热粘弹性问题与相变的热方程之间的耦合。开发的程序首先应用于部分饱和交流试样的表征测试建模，已证明是相关的。然后，为了更接近现场条件，对部分饱和的双层 AC 结构进行了原始的冻融试验。该测试导致在第二次冻融循环期间两层分层。其建模表明，界面破裂是由样品中产生的差异应变和自应力场触发的。这些结果可以为坑洞问题的初始化提供解释。