集料形态特征对集料-沥青黏附及水稳定性的影响

为评价集料形态特征对集料-沥青黏附性及其体系水稳定性的影响,提出了一种定量测试集料-沥青黏附性的新方法.借助集料图像测量系统(AIMS)测试了5种集料的形态特征,并对不同形态集料沥青混合料的水稳定性进行评价,建立了集料形态特征与集料-沥青黏附性及水稳定性的关系,同时基于灰色关联法分析了集料形态特征对集料-沥青黏附性及水稳定性的影响排序.结果 表明:提出的集料-沥青黏附性定量测试方法简单、可靠;沥青混合料水稳定性最佳的棱角性为2500～3000,球度为0.65～0.75;随着集料表面纹理的增大,沥青混合料的水稳定性增强;集料表面纹理对集料-沥青黏附性的影响最大,棱角性对沥青混合料浸水飞散损失指标的影响最大,球度对沥青混合料冻融劈裂强度比、浸水车辙变形拐点指标的影响最大.

Effects of Aggregate Morphological Characteristics on Adhesion of Aggregate-Asphalt and Its Moisture Stability

In order to evaluate the influence of aggregate morphological on aggregate-asphalt adhesion and its water stability, a new method of quantitative aggregate-asphalt adhesion test was proposed. The morphological characteristics of aggregates from five sources were tested by Aggregate Image Measurement System (AIMS), and the water stability of asphalt mixture with different aggregate morphological characteristics were evaluated. The relation of aggregate morphological characteristics with adhesion of aggregate-asphalt and its moisture susceptibility was established. The influence of aggregate morphology on the adhesion and water stability was analyzed based on the grey correlation method. The results show that the proposed quantitative test method of aggregate-asphalt adhesion is simple and reliable. The water stability of asphalt mixture would be best when the aggregates morphologies with best angularity in the range of 2500 ~ 3000 and the best sphericity in the range of 0.65 ~ 0.7. With the increase of surface texture, the water stability of asphalt mixture was enhanced. The surface texture, angularity and sphericity had the greatest influence on aggregate-asphalt adhesion, water immersion flying loss, freeze-thaw splitting strength ratio and stripping inflection point, respectively.