【作者】 周吴军；

【导师】 王昌衡；

【作者基本信息】 湖南大学 ， 道路与铁道工程， 2009， 硕士

【摘要】 沥青路面是我国路面结构的主要型式。沥青混合料的离析是沥青路面产生早期破坏的主要原因之一。国内外许多研究学者针对控制沥青混合料在施工过程中发生离析的方法展开了许多研究,取得了较大的进步。目前,对沥青路面离析的判定和检测方法主要依赖于观察法、铺沙法、路面雷达法和取芯法,这些方法存在主观性强、测速慢和误差大,且具有一定的破坏性。为此,亟需提出一种快速高效、客观无损的沥青路面离析检测技术。分形理论作为研究自然界复杂现象的非线性理论新工具,在描述评价具有层次连续性、随机性或不规则性等特征的对象方面,具有很强的功能。对微观、细观层次下的精细结构和自相似特征能有效地描述。沥青路面从级配设计到铺筑成型后,在体积和性能形态方面均表现出统计自相似性,传统的经验指标很难对离析进行准确的描述和评价,故可以借助于分形理论进行定量地分析。本文借助激光断面构造仪,测量获得能精确描述沥青路面表面轮廓曲折边界的数据,基于分形理论提出分维特征参数作为描述沥青混合料离析的指标,对级配特征和路表面构造轮廓具有的分形特征进行计算分析,发现不同级配和路表面构造轮廓具有不同分维值。在试验研究和理论分析的基础上,提出粗细集料不同级配的分形评价模式和路表面构造轮廓的分形评价指标。文中所得结论和研究方法对沥青混凝土路面离析判别技术的研究和应用具有重要的借鉴意义。更多还原

【Abstract】 Asphalt pavement has become the primary pavement type in our country. The segregation of asphalt mixture is one of the main reasons for the damage in the early stage of asphalt pavement. Many researchers all over the world have explored extensively research on the segregation of the asphalt mixture during the process of the construction. Recently, the test and estimation of segregation in asphalt pavements mainly rely on traditional methods as visual identification, sand patch testing, ground-penetrating radar and coring. Due to some disadvantages of these test methods metioned, such as slow test speed, subjectivity, deviation and some destructivity. Therefore, it is urgent to find a nondestructive segregation test technology of asphalt pavement with high speed and objectivity.Fractal theory is a new theoretical non-linear tool to study complicate phenomena in nature, and has a powerful function in describing and evaluating the phenomena with continuous in scale, stochastic in distribute or erose in shape. Fractal theory can describe microstructure, ultrastructure and self-similarity characteristics effectively. From gradation design to pavement construction, there are so many self-similarity characteristics in asphalt pavement. Based on traditional index, it is difficult to describe and evaluate the segregation accurately. In this paper, we choose fractal theory as the method to give them a quantitative analysis.In this paper we get a lot of data, which can describe the surface of asphalt pavement directly, based on Laser Cross Section Instrument. Turn to fractal theory and propose fractal index to describe segregation, then study the fractal characteristics of gradation and pavement texture and find that different fractal dimensions can reflect different details of gradation and pavement texture. Based on the tests and fractal analysis, propose a fractal evaluate model of gradations and fractal evaluate index of pavement texture.The conclusions and fractal method of this paper will provide an important reference for research and application of segeregation evaluation in the further.更多还原