AC-25级配离析的分形评价标准及预测方法

发布时间：2018-10-26 06:45

【摘要】：为探究沥青混合料设计过程中的级配离析控制问题,选取沥青混合料AC-25中具有代表性的7种级配类型,对不同级配类型的沥青混合料在摊铺后碾压前,选取3个典型点位进行取样,分析其级配变化状况,计算其级配离析变异指标,并对成型路面的构造深度进行了测试;从沥青混合料集料级配的自相似性出发,利用分形理论计算了7种级配的分形维值;采用SPSS统计软件对不同级配分维值、级配离析指标与路面构造深度之间的关系进行了回归分析。研究结果表明:密级配沥青混合料AC-25的级配分维值与级配离析指标间存在较强的线性关系,采用级配分维值建立的级配离析指标线性回归模型可用作对设计级配的评价;级配离析指标与路面构造深度比之间存在显著的指数相关关系,验证了级配离析指标在反映已建路面质量均匀性上的合理性。同时借鉴NCHRP 441相关标准,提出了基于级配设计阶段的AC-25离析评价标准和预测方法,为沥青混合料设计阶段有效控制路面离析提供了参考。
[Abstract]:In order to explore the control of gradation segregation in the process of asphalt mixture design, seven typical gradation types of asphalt mixture AC-25 were selected, and the asphalt mixture with different gradation types was rolled before spreading. Three typical points were selected for sampling, the gradation variation was analyzed, the gradation segregation variation index was calculated, and the structural depth of the formed pavement was tested. Based on the self-similarity of aggregate gradation of asphalt mixture, the fractal dimension of seven gradation is calculated by fractal theory. The regression analysis of the relationship between the fractal dimension of different gradation, the index of gradation segregation and the depth of pavement structure is carried out by using SPSS software. The results show that there is a strong linear relationship between the gradation dimension and gradation segregation index of dense gradation asphalt mixture AC-25, and the linear regression model of gradation segregation index established by gradation fractal dimension can be used to evaluate the design gradation. There is a significant exponential correlation between gradation segregation index and pavement structure depth ratio, which verifies the rationality of gradation segregation index in reflecting the uniformity of pavement quality. At the same time, using NCHRP 441 as reference, the paper puts forward the evaluation standard and prediction method of AC-25 segregation based on gradation design stage, which provides a reference for effectively controlling pavement segregation in asphalt mixture design stage.
【作者单位】：长安大学公路学院;交通运输部公路科学研究院;新疆机场(集团)有限责任公司乌鲁木齐国际机场分公司;
【基金】：交通运输部交通应用基础研究项目(2011-319-812-410) 陕西省自然科学基础研究计划项目(S2010JC3247)
【分类号】：U414

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