粗集料性能对沥青混合料高温性能的影响

Influence of Coarse Aggregate Performance on High Temperature Performance of Asphalt Mixture

为明确沥青混合料中粗集料的表面特性及几何形状对高温性能的影响机理,进而为集料选择及性能评定提供参考,结合当前沥青混合料高温性能的研究状况,通过大量室内试验,分析了粗集料表面纹理、棱角性、扁平颗粒含量对沥青混合料高温性能的影响。研究结果表明:粗集料表面纹理与内摩擦角、动稳定度呈线性关系,表面纹理越大,动稳定度越高;平均棱角性系数大于14.5%时,沥青混合料动稳定度提高幅度明显;粗集料扁平颗粒含量越高,其混合料的高温稳定性越差,同时不同级配条件下,扁平颗粒含量对混合料高温性能影响程度不同,骨架型级配最为敏感。

In order to clarify the influence mechanism of property of surface texture and geometry of coarse aggreagate on the high temperature performance in the asphalt mixture, and to offer reference for the aggregate production and improve asphalt pavement rutting resistance, combined with the existing research progress of high temperature performance of asphalt mixture, influences of the surface texture, the angularity and the content of flat particle on high temperature performance of the asphalt mixture were analyzed by a large number of laboratory experiments. The results show that there exists a linear relationship between surface texture of coarse aggeragate and friction angle and dynamic stability. The larger the surface texture is, the better the dynamic stability is. When average angularity coefficient is larger than 14. 5%, dynamic stability of asphalt mixture enhances greatly. The more the content of flat particle is, the worse the high temperature performance is and the content of flat particle shows different influences on high temperature performance of asphalt mixture with various gradations, in which the frame type gradation is the most sensitive to content of flat particle.