基于分形理论的沥青混合料抗滑耐久性评价研究

沥青混合料的设计过程均考虑到高温,低温,水损等的影响,并在设计过程中进行了相关实验来保证混合料的设计质量,但是在国内外沥青混合料设计中,并没有表征其抗滑耐久性的指标,为解决此问题,引入分形维数作为沥青混合料的抗滑耐久性评价指标。研究过程采用快速,简便的室内搓揉试验对车辙板进行不同时间段的搓揉,室内模拟路面抗滑衰减,用工业CT机扫描出试件断面高精度图像,photoshop技术提取断面轮廓曲线,并且对轮廓曲线采用分形理论进行分析和评价,编写MATLAB程序计算试件断面轮廓曲线的分形维数,最后对分形维数进行曲线拟合得出沥青混合料抗滑衰减规律的结论。为进一步证实用分形维数来表征沥青混合料抗滑衰减的准确合理性,测量不同搓揉阶段的车辙板的构造深度(MTD)和摆值(BPN),最终可知随着车辙板搓揉时间的不断变大,MTD,BPN,分形维数,三者均呈现不断递减的趋势,即对比验证合理可靠。因此,断面构造的分形维数能够很好的评价沥青混合料的抗滑耐久性及其衰减规律。

Evaluation of durability against sliding on the asphalt mix fractal theory

Asphalt mixture design process take into account the effects of heat, cold, water damage, etc., and conducted experiments in the design process to ensure the quality of design mix, but at home and abroad asphalt mixture design, and did not characterize the indicators durability against sliding, to solve this problem, this paper introduces the fractal dimension as anti-slide durability evaluation of asphalt mixtures. This research process uses a quick and easy indoor rub test to rub the rut board in different time period, and simulates outdoor actual road for anti-slide decay. Then it utilizes the industrial CT machine to scan high resolution image of cross-section in the rut board and extracts cross-section profile curve with Photoshop skills. Also, it starts to analyze and evaluate profile curve based on fractal theories. Afterwards, it can redact MATLAB routing to calculate test specimen for fractal dimension of cross-section profile curve. Finally, there is a conclusion of anti-slide decay law according to curve fitting with fractal dimension. To further confirm to characterize asphalt attenuation accuracy and reasonableness of the anti-slide, measuring the depth of the different tectonic plates rub stages of the rut (MTD) and put value (BPN) with a fractal dimension, eventually known as the rut board knead time continues to become larger, MTD, BPN, fractal dimension, which are all showing diminishing trend that contrast verify reasonable and reliable. Therefore, the fractal dimension can be a good cross-section structure of asphalt skid evaluate the durability of its decay law.