碳化对混凝土孔结构的影响  

Effect of carbonization on concrete pore structure

作　　者：赵燕茹[1] 喻泊厅 王磊[1] 王志慧 ZHAO Yanru;YU Boting;WANG Lei;WANG Zhihui(Key Laboratory of Civil Engineering Structure and Mechanics,Inner Mongolia Autonomous Region,Inner Mongolia University of Technology,Hohhot 010051,China)

机构地区：[1]内蒙古工业大学内蒙古自治区土木工程结构与力学重点实验室,内蒙古呼和浩特010051

出　　处：《混凝土》2021年第12期7-10,15,共5页Concrete

基　　金：国家自然科学基金项目(11762015,11362013)。

摘　　要：通过对混凝土快速碳化试验和微观孔结构测试,研究了碳化龄期对碳化深度和碳化区试样密度的影响,分析了碳化区孔隙率和孔径大小随碳化龄期的变化规律,采用灰熵法探讨了4种孔隙对碳化区密度的影响程度,并基于热力学分型模型计算得到各个碳化龄期下碳化区孔结构分形维数。结果表明:混凝土碳化深度随碳化龄期的增加而增加,密度随碳化龄期先增加后减小,7 d时密度最大;碳化填充了多害孔和有害孔,提高了无害孔比例,并使多害孔更好的分散,连通和集聚了少害孔;对碳化区密度影响最大的是有害孔表面积,其分形维数随碳化龄期的增加出现了先降低后增加的趋势;碳化区密度与有害孔分形维数相关性良好,碳化区密度随有害孔分形维数的增加而减小。Through the rapid carbonization test and microscopic pore structure test,the effects of carbonation age on carbonization depth and the density of concrete in carbonization zone were studied.The variation of porosity and pore size in carbonization zone with carbonation age was analyzed.Gray entropy method was used to analyze the influence of four pore sizes on the density of concrete in carbonized zone.and the fractal dimension of pore structure in the carbonization zone at each carbon age was calculated based on the thermodynamic classification model.The results show that the carbonation depth of concrete increases with the increase of carbonation age,the density increases first and then decreases with the carbonation age,and the density is the largest at 7 days.The carbonization fills the harmful and much harmful pores,improves the ratio of harmless pores and make the more harmful pores better disperse,connecte and gather.The most important influence on the density of carbonized zone is the surface area of harmful pore,and the fractal dimension increases first and then increases with the increase of carbonation age.The correlation of the density of concrete in carbonization zone with the fractal dimension of the harmful pores is good,and the density of concrete in the carbonized zone decreases with the increase of the fractal dimension of the harmful pores.

关 键 词：碳化 孔结构 灰熵 分形维数 

分 类 号：TU528.01[建筑科学—建筑技术科学]