1、 中文 1740 字 毕业设计 外文资料翻译 题 目 分形维数与沥青混凝土 力学性能之间的关系 学 院 土木建筑 专 业 土木工程 班 级 土木 0803 学 生 学 号 指导教师 二 一 二 年 三 月 六 日 The Relationship between the Fractal Dimension and Mechanical Properties of Asphalt Concrete Seracettin Arasan 1 , Engin Yener 2 , Fatih Hattatoglu 3 , Suat Akbulut 4 , Sinan Hinislioglu 5 1, 3
2、, 4, 5-Ataturk University, Engineering Faculty, Department of Civil Engineering ,25240 Erzurum, Turkey 2-Bayburt University, Department of Civil Engineering, Bayburt, Turkey arasanatauni.edu.tr ABSTRACT The importance of the shape of aggregate particles on their mechanical behavior is well recognize
3、d. In asphalt concrete, the shape of aggregate particles affects the durability, workability, shear resistance, tensile strength, stiffness, fatigue response, and optimum binder content of the mixture. Due to their irregularity, the shape of aggregates is not accurately described by Euclidian geomet
4、ry. However, fractal theory uses the concept of fractal dimension, DR, as a way to describe the shape of aggregates. This paper describes a study of the influence of fractal dimension on mechanical properties of asphalt concrete.The flow of asphalt concrete decreases and Marshall Stability increases
5、 when the fractal dimension of aggregate increases Keywords: Fractal dimension, asphalt concrete, Marshall Stability, flow, aggregate 1. Introduction The importance of the shape of aggregate particles on their mechanical behavior is also well recognized. In asphalt concrete, the shape of aggregate p
6、articles affects the durability, workability, shear resistance, tensile strength, stiffness, fatigue response, and optimum binder content of the mixture 1. The successful quantification of aggregate geometric irregularities is essential for understanding their effects on pavement performance and for
7、 selecting aggregates to produce pavements of adequate quality 2. Aggregate morphological characteristics are very complex and cannot be characterized adequately by any single test. As a result, conflicting results have been reported on how aggregate shape influences the quality of HMA mixtures 3-9.
8、 Due to their irregularity, the shape of aggregates is not accurately described by Euclidian geometry. Fractals are relatively new mathematical concept for describing the geometry of irregularly shaped objects in terms of frictional numbers rather than integer. The concept of fractals introduced by
9、Mandelbrot 10, which has the shape formed in nature, has been usually analyzed using Euclidian geometry. The key parameter for fractal - 1 - analysis is the fractal dimension, which is a real noninteger number, differing from the more familiar Euclidean or topological dimension. The fractal dimensio
10、n for a line of any shape varies between one and two, and for a surface between two and three. Fractaltheory uses the concept of fractal dimension, DR, as a way to describe the shape of aggregates. In recent years, fractal geometry techniques have found widespread applications in many disciplines, i
11、ncluding medicine, biology, geography, meteorology, manufacturing, and material science. Relatively, there have been a few applications of fractal geometry in civil engineering. Some studies have been devoted to developing procedures to determine the particle fractal dimensions 11-17. Others have fo
12、cused on the effect of fractal dimension of aggregate on engineering properties of soils 18, 19 and asphalt concrete 20, 21. However, there is no comprehensive study that investigated the effect of aggregate fractal dimension to the Marshall stability, flow, and Marshall Quotient (MQ). Consequently,
13、 the present study was undertaken to verify whether there is a relationship between the fractal dimension (DR) and the mechanical properties of asphalt concrete. 2. Materials and Methods The bitumen used was AC-20 bitumen. Crushed Basalt was used as the aggregate material. A typical heavy traffic gr
14、adation for hot mix asphalts (HMA), designated as Type I in the Turkish State Highway Specifications, and was selected. The Marshall stability and flow tests were carried out following the procedure of the Test Method for Resistance of Plastic Flow of Bituminous Mixtures Using Marshall Apparatus in
15、ASTM D1559. The imaging system used by the authors consists of a Nikon D80 Camera and Micro 60 mm objective manufactured by Nikon. ImageJ was used as the image analysis program. The other properties of used materials test procedures, imaging system and image processing steps were also detailed in Ar
16、asan et al. 22. Additionally, fractal dimension of aggregates was calculated with areaperimeter method 16. 3. Correlation between fractal dimension and mechanical properties The correlation between fractal dimension of aggregate and flow, Marshall Stability, and MQ of asphalt concrete are presented
17、in Figure1, 2, and 3, respectively. It could be seen that the flow decreased as the fractal dimension increased (Figure1). On the other hand, since fractal dimension has a minimum value of 1 for a circle and larger values longer or thinner shapes, or aggregate having rough edges, it can be concluded that approximation of the shape of aggregates to sphere or smooth aggregate surfaces resulted in bigger flow values.
