基于数字图像处理技术的引气混凝土冻融损伤定量评价(英文)  

Quantitative Damage Evaluation of Air-Entrained Concrete Suffered Freezing-Thawing by Digital-Image-Processing Technique

作　　者：李曙光[1] 陈改新[1] 纪国晋[1] 刘艳霞[1] 

机构地区：[1]中国水利水电科学研究院、流域水循环模拟与调控国家重点实验室,北京100038

出　　处：《硅酸盐学报》2014年第8期951-959,共9页Journal of The Chinese Ceramic Society

基　　金：国家“973”计划(2013CB035901);国家科技支撑计划(2013BAB06B02);中国水科院专项(结集1321&1246)

摘　　要：对受冻混凝土建筑物进行维修加固的前提是对混凝土的冻融损伤程度进行科学合理的评价。提出一种基于真空荧光环氧浸渍技术和数字图像处理技术进行混凝土微裂纹量化分析的方法。对经受不同冻融循环劣化的引气混凝土试件进行了宏观力学性能测试和微裂纹量化分析,得到了混凝土试件基体中冻融微裂纹结构特征的演化规律,并比较了砂浆微裂纹和过渡区微裂纹结构特征参数的差异。结果表明:在早期冻融损伤过程中,引气混凝土基体微裂纹的长度密度、面积密度和裂纹宽度均随冻融损伤度的增大而增大;过渡区微裂纹是冻融损伤微裂纹的主要部分;相对抗压强度、相对抗弯强度、相对轴拉强度和冻融损伤度与微裂纹密度之间均存在很强的相关关系;微裂纹量化分析技术有望发展成为评价混凝土冻融损伤的一个新方法。A method of quantifying the microcrack patterns in concrete based on vacuum-epoxy-impregnation method and digital- image-processing （ DIP） technique was proposed. The quantitative microcrack analysis and mechanical tests （i. e. , compressive tests, flexural tests and axial tensile tests } were performed on the specimens suffered at different freezing-thawing（FT} cycles. The microcrack characteristics of the matrix cracks in the concrete specimens were evaluated, and the microcrack patterns of in- terracial transition zone （ITZ） cracks and the mortar cracks both were analyzed. The results show that the length density, area density and crack width in the matrix o{ air-entrained concrete all increase with the increase of FT damage degree during the early FT deterioration process, and the ITZ cracks instead of the mortar cracks are the major part of FT-caused microcracks. There are strong corresponding relationships among the relative compressive strength, the relative flexural strength, the rela- tive axial tensile strength, the FT damage degree and the microcraek densities. It is indicated that the quantitative microcrack analysis could be used as a promising method of quantifying FT damage in concrete.

关 键 词：引气混凝土 冻融 损伤评价 微裂纹 数字图像处理 过渡区 

分 类 号：TV431[水利工程—水工结构工程]