不同马歇尔击实方法乳化沥青冷再生混合料细微观结构性能研究

发布时间：2018-12-10 22:04

【摘要】：基于X-ray CT和数字图像处理技术研究了五种击实方法下乳化沥青冷再生混合料试件内部粗颗粒的颗粒主轴取向角和细微观空隙分布特征,并通过统计分析提出数学模型对其进行表征。结果表明:马歇尔击实方式下乳化沥青冷再生混合料粗集料取向角基本符合洛伦兹分布,第二遍击实次数越多,粗集料取向角减小幅度越大,增大二次击实功虽然可改善乳化沥青冷再生混合料的颗粒分布结构,但远没有增大第一次击实功效果明显;"50+25"、"60+15法"空级配中大孔百分比明显减小,同时小孔百分比显著增大,随着第二遍击实次数的减小,乳化沥青冷再生混合料平均孔径呈先减小后增大的变化趋势,马歇尔试件平均孔径与劈裂强度之间具有良好的线性拟合关系。二次击实可减小乳化沥青冷再生混合料内部的大孔,改善粗集料的骨架承载结构,综合考虑击实方法对乳化沥青冷再生混合料劈裂强度、粗颗粒存在形态以及细微观空隙分布特征的影响,推荐采用"50+25法"成型马歇尔试件。
[Abstract]:Based on X-ray CT and digital image processing techniques, the main axis orientation angle and microscopic void distribution of coarse particles in cold recycled asphalt mixture were studied under five compaction methods. A mathematical model is proposed to characterize it by statistical analysis. The results show that the orientation angle of coarse aggregate of cold recycled asphalt mixture under Marshall compaction is basically in accordance with Lorentz distribution. The more the compaction times of the second time, the greater the decrease of coarse aggregate orientation angle. Although increasing the secondary compaction work can improve the particle distribution structure of emulsified asphalt cold recycled mixture, but far from increasing the first compaction work, the effect is obvious. The percentage of large pores in "5025" and "6015 methods" in space gradation decreased obviously, while the percentage of small holes increased significantly. With the decrease of the second compaction times, the average pore size of emulsified asphalt cold recycled mixture decreased first and then increased. There is a good linear fitting relationship between the average pore size and the splitting strength of the Marshall specimen. The secondary compaction can reduce the large hole in the cold recycled mixture of emulsified asphalt, improve the skeleton bearing structure of coarse aggregate, and synthetically consider the splitting strength of cold recycled asphalt mixture with the compaction method. Due to the influence of the morphology of coarse particles and the distribution of microscopic voids, the "5025" method is recommended to be used to form Marshall specimen.
【作者单位】：南通职业大学建筑工程学院;
【基金】：国家自然基金项目(511754262) 交通运输部科技项目(20143188146181) 陕西省交通运输厅科技项目(2014P250)
【分类号】：U414

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