低水胶比偏高岭土混凝土的强度和细观结构的分形特征  

Strength and fractal characteristic of meso-structure of concrete with metakaolin and low water-binder ratio

作　　者：刘红彬[1] 鞠杨[1,2] 彭瑞东[1] 肖凯璐[3] 唐伟奇[3] 盛星汉 马唯哲 

机构地区：[1]中国矿业大学(北京)煤炭资源与安全开采国家重点实验室,北京100083 [2]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116 [3]中国矿业大学(北京)力学与建筑工程学院,北京100083 [4]江苏常州市武进建筑设计院有限公司,江苏常州213100

出　　处：《煤炭学报》2015年第8期1820-1826,共7页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(51374211);博士学科点专项科研基金资助项目(20110023110015);北京市教委共建项目

摘　　要：为探明低水胶比偏高岭土混凝土的力学性能,以及定量表征掺入偏高岭土后混凝土内部细观结构的变化规律,测试了不同偏高岭土掺量混凝土的抗压、劈裂和弯折强度;利用扫描电镜拍摄了混凝土水化产物微结构的SEM图像;运用分形理论计算分析了SEM图像的分形维数及其变化规律;并研究探讨了分形维数和强度的关系。研究表明:偏高岭土可以有效提高和改善混凝土的力学性能和细观结构;分形方法能够定量分析偏高岭土混凝土内部细观结构的变化特征,分形维数随着偏高岭土掺量的增加呈现降低趋势;抗压强度和分形维数存在良好的指数负相关性,抗压强度随分形维数的增大而减小。To investigate the effect of five different metakaolin volumetric contents on the strength of concrete with low water-binder ratio,and quantitatively characterize the variations of meso-structures of concrete,the compressive strength,split tensile strength and flexural tensile strength were tested,and the meso-structure of concrete hydration products were captured by the scanning electron microscope( SEM). The fractal dimension of the surface and the variations of concrete hydration products were calculated based on fractal theory,and the relationship between the strength and fractal dimension were studied. It is shown that metakaolin can improve the strength and the meso-structure of concrete. Fractal method can quantitatively analyze the meso-structure of concrete with metakaolin,the fractal dimensions decrease with an increase of metakaolin volumetric contents. It is revealed that there is a negative exponential relation between compressive strength and fractal dimensions,and the compressive strength of concrete decreases with the increase of fractal dimensions.

关 键 词：低水胶比 偏高岭土混凝土 强度 细观结构 分形 

分 类 号：TU528[建筑科学—建筑技术科学]