密级配沥青混合料均匀性评价

Evaluation of Uniformity of Dense Graded Asphalt Mixture

为了克服传统沥青混合料均匀性评价准确度低和耗时长的不足,采用数字图像技术定量评价不同类型的密级配沥青混合料均匀性,提出相邻粗集料区域面积比相对平均差作为评价指标来分析评价SMA-13和AC-13C两种类型混合料的均匀性。结果表明:SMA-13比AC-13C的相邻粗集料区域面积比相对平均差降低了33.1%,SMA-13的均匀性显著好于AC-13C。集料粒径的不同对混合料均匀性有较大影响,各档粗集料的均匀性随粒径增长呈二次抛物线分布规律,4.5~9.5 mm档位集料的均匀性最好,大于13.2 mm档位集料均匀性最差。混合料的局部与整体均匀性存在较好的对比效果。

In order to overcome the shortcomings of low accuracy and long time consuming of traditional asphalt mixture uniformity evaluation, the digital image technology is used to quantitatively evaluate the uniformity of different types of dense graded asphalt mixture. The relative average difference of area ratio of adjacent coarse aggregate areas is proposed as an evaluation index to analyze and evaluate the uniformity of SMA-13 and AC-13C mixtures. The results show that the relative average difference of area ratio of adjacent coarse aggregate areas of SMA-13 is reduced by 33.1% than AC-13C. The uniformity of SMA-13 is significantly better than AC-13C. The different particle size of aggregate has a great influence on the uniformity of mixture. The uniformity of each coarse aggregate presents a quadratic parabola distribution law with the increase of particle size. 4.5 ~ 9.5 mm graded aggregates have the best uniformity.The aggregate uniformity greater than 13.2 mm is the worst. There is a good contrast effect between the local and overall uniformities of the mixture.