基于CT试验的混凝土裂纹扩展演化研究  

Concrete crack evolution research based on CT test

作　　者：刘京红[1] 史攀飞 杨跃飞[1] 王印[1] 刘子倩 

机构地区：[1]河北农业大学城乡建设学院,河北保定071001 [2]河北省第四建筑工程有限公司第六分公司,河北保定071000

出　　处：《混凝土》2017年第4期74-77,共4页Concrete

基　　金：国家重点基础研究发展规划(973)项目(2010CB226801);河北省教育厅重点项目(ZD2014073);河北农业大学理工基金项目(LG201403);河北农业大学中青年教师境外研修项目(2014)

摘　　要：针对混凝土宏观性能指标与破坏特性细观参数之间关系的技术难题,采用工业CT对单轴压缩条件下的混凝土试样进行了CT扫描试验;利用图像处理技术对混凝土CT图像进行分析,得到不同加载阶段混凝土孔隙和裂纹的三维细观模型及孔隙率变化规律。运用分形理论建立了CT图像分形维数计算模型,对混凝土CT图像分形特征进行了研究。结果表明:混凝土孔隙体积和分形维数的快速增大是混凝土失稳破坏的预警信息;利用混凝土CT三维重建图像结合分形理论观察研究混凝土裂纹扩展全过程,为有效分析混凝土细观损伤破坏提供了新技术。The relationship between concrete macroeconomic performance and macro parameters of the failure characteristics were technical problem of many field.CT scanning test on concrete specimens were conducted in the condition of uniaxial compression.The change regulations of concrete porosity, the 3D micro-mechanical model and the porosity on different loading stages can be got with image process technology.Fractal dimension calculation model was established by using the fractal theory.Authors did a research on the fractal characteristic of concrete CT images.The result shows that with the increasing load on the specimens,the change regulations of concrete porosity,pore volume and box-counting dimension were the same.The rapid increasing of concrete pore volume and fractal dimension can be regarded as a sign of unstable failure in concrete.Observing and analyzing the whole process about the appearance and evolution of the cracks in concrete with 3D reconstruction images as well as fractal theory provides a new method for analyzing the process of the damage evolution and failure on concrete.

关 键 词：混凝土 CT试验 孔隙率 三维细观模型 分形维数 

分 类 号：TU528.01[建筑科学—建筑技术科学]