基于接触应力集中的沥青路面抗滑性能评价研究

为了给抗滑表层沥青混合料级配设计提供参考,基于高精度压力胶片测试技术,开展不同搓揉时间下的胎/路接触应力分布特性研究。通过2种粗集料2种类型沥青混合料的对比,研究轮胎作用下沥青路面的抗滑性能衰减规律;并从接触力学的角度建立沥青路面抗滑性能评价指标。结果表明:轮胎与路面接触应力呈现显著的非均匀分布,主要包括有效接触面积与应力集中效应。初始状态下胎/路有效接触面积与应力集中主要与级配设计有关;而在搓揉过程中,随着路面构造的二次圧密与粗集料磨耗,有效接触面积持续增加,应力集中减少;应力集中分布度指标可以较好描述应力集中效应。分析表明,轮胎接触应力集中与路面摩擦系数呈现良好的线性关系。试验证明,骨架密实型级配与优质粗集料均有利于提高沥青路面抗滑耐久性能;而级配的影响更显著,磨耗层设计中应当给以重视。

Evaluation Research on Asphalt Pavement Skid Resistance Based on Contact Stress Concentration

In order to provide a reference for gradation design of asphalt mixture anti-slip surface, the contact stress distribution characteristics of tire/road under different kneading time were studied based on high precision pressure film technology. By comparing two kinds of coarse aggregate and two types of asphalt mixture, the attenuation law of asphalt pavement skid resistance performance under the action of wheel-load was studied. And the evaluation index of asphalt pavement skid resistance performance was established from contact mechanics standpoint. The results showed that: the contact stress between tire and road is a kind of significant non-uniform distribution, including the effective contact area and stress concentration effect. In the initial state, the effective contact area and stress concentration of the tire/road are mainly related to the gradation design. However, the effective contact area continues to increase and the stress concentration decreases with the second compaction and coarse aggregate abrasion of pavement surface in the kneading process. Stress concentration distribution index can well describe the stress concentration effect, and the analysis showed that there is a good linear relationship between tire contact stress concentration and road friction coefficient. Experiments showed that the skeleton dense gradation and high-quality coarse aggregate are conducive to improve the durability of asphalt pavement skid-resistant performance. Due to the effect of mineral aggregate gradation is more significant, it should be emphasized in the design of wearing surface.