Cheng Yongchun, Wang Wensheng, Tao Jinglin, Xu Meng, Xu Xiaoli, Ma Guirong, Wang Shurong
College of Transportation, Jilin University, Changchun 130025, China.
Jiangxi Transportation Institute, Nanchang 330200, China.
Materials (Basel). 2018 Oct 19;11(10):2034. doi: 10.3390/ma11102034.
Aggregate is an indispensable raw material for asphalt pavement construction. This study evaluates the influences of aggregate morphological characteristics on the high- and low-temperature viscoelasticity of asphalt mixtures. Based on simplex lattice mixture design (SLD), asphalt mix samples were designed and prepared with the same gradation but three different types of aggregates. Subsequently, three morphological characteristics of aggregate (roundness, perimeter index, and erosion-dilation area ratio) are presented to characterize fine and coarse aggregates. Then based on Burgers viscoelastic model, uniaxial compression static creep test was carried out to analyze the high-temperature viscoelastic properties for asphalt mortar and mixture. Meanwhile fitting Prony series models have been utilized to represent relaxation modulus conversed from creep compliance and the low-temperature relaxation characteristics can be also discussed. The experimental results indicated that morphological characteristics of aggregate, especially fine aggregates, are strongly correlated with the viscoelastic parameters of asphalt mixtures. However, the complex morphological characteristics of aggregates have opposite influences on the high- and low-temperature viscoelastic parameters. Therefore, when considering both high- and low-temperature viscoelastic properties, the aggregate proportion was optimized for the appropriate morphological characteristics, which will provide a reference for asphalt mixture design.
集料是沥青路面施工不可或缺的原材料。本研究评估了集料形态特征对沥青混合料高低温粘弹性的影响。基于单纯形格子混合设计（SLD），设计并制备了具有相同级配但三种不同类型集料的沥青混合料样本。随后，提出了集料的三种形态特征（圆度、周长指数和蚀扩面积比）来表征细集料和粗集料。然后基于伯格粘弹性模型，进行单轴压缩静态蠕变试验以分析沥青胶浆和混合料的高温粘弹性性能。同时，利用拟合的 Prony 级数模型来表示由蠕变柔量转换得到的松弛模量，并讨论低温松弛特性。实验结果表明，集料的形态特征，尤其是细集料，与沥青混合料的粘弹性参数密切相关。然而，集料复杂的形态特征对高低温粘弹性参数有相反的影响。因此，在考虑高低温粘弹性性能时，针对合适的形态特征优化集料比例，这将为沥青混合料设计提供参考。
