基于微观结构分析的水泥稳定碎石微裂自愈性能

Self-healing Properties of Micro-cracks of Cement Stabilized Macadam Based on Microstructure Analysis

为了从微观结构角度对水泥稳定碎石微裂自愈合性能进行量化和直观的分析,利用数显式裂缝宽度监测仪KON-FK(B)和万向体视显微镜XTZ-05T对不同微裂程度下微裂缝随龄期增长变化的宽度值和微裂缝内部自愈产物随龄期的生成情况进行实时监测和观察分析。并通过SPSS软件的描述性统计功能对所测微裂缝宽度值进行统计分析,得出不同微裂程度及愈合后微裂缝的宽度值分布范围;基于像素面积计算法原理,借助图像处理软件Imagemagick对微裂缝随龄期增长自愈合情况的图像进一步处理分析并计算,得出不同龄期下愈合产物的覆盖率及不同微裂程度下愈合覆盖率的对数拟合方程。结果表明:微裂后的水泥稳定碎石裂缝宽度值随龄期逐渐减小,且微裂缝内部生成的愈合产物覆盖率不断增长,后期基本可达完全愈合状态。从而证明了微裂后的水泥稳定碎石在宏观力学性能和微观结构特性上均具有良好的自愈合效果。

To make a quantitative and ocular analysis of the self-healing property of micro-cracks based on the microstructure of cement stabilized macadam, the changes of the width of micro-cracks and the generation of healing products with the increase of age at different levels of micro-cracks were monitored by the digital crack width monitor KON-FK（B） in real time and observed and analyzed by the universal stereo microscope XTZ-05T. With the descriptive statistics function of SPSS software ,the processing and statistical analysis of the width of micro-cracks were completed. As a result, ranges of micro-cracks＇ width before and after self-healing were concluded. Based on the principle of pixel area calculation method, images of the self-healing products as age increased were further processed and analyzed by the image processing software Imagemagiek. And after the calculation, the coverage of self-healing products in different periods and logarithmic fitting equation of the pattern of the coverage at different levels of micro-cracks were concluded. The results show that micro-cracks＇ width of cement stabilized macadam gradually reduces with the increase of age and the coverage of self-healing products which are generated inside micro-cracks constantly enlarges. And in the later stage micro-cracks basically realize a complete healing. It proves that cement stabilized macadam after micro-cracks occur has a good capacity of self- healing in therms of both macroscopic mechanical properties and micro-structural characteristics.