摘要
受混凝土结构尺寸效应的影响,实体混凝土结构中温度场与标准养护或同条件养护具有较大差异,其耐久性的发展也有所不同。本文针对C40~C60三种强度等级混凝土,研究了20℃~80℃四种养护温度对混凝土抗氯离子渗透性的影响规律,并采用TG、MIP等测试分析了养护温度对胶凝材料水化过程及孔结构的影响及机理。研究表明:随混凝土养护温度的提高,混凝土氯离子扩散系数不断降低,但当养护温度超过60℃时,对混凝土胶凝材料水化程度、孔结构分布等具有不利的影响;建立了等效龄期与混凝土氯离子扩散系数之间的对数函数模型,可用于预测氯盐环境下混凝土预制构件移运安装时间,工程应用效果良好。
Affected by the size effect of concrete structure, the temperature of concrete structure is quite different from standard curing or same curing condition, and development of concrete structure durability is also varied. Effects of curing temperatures at 20℃~80℃ on chloride diffusion coefficient of concrete are studied for C40~C60 three strength grade concrete. TG and MIP are used to analyze the influence of curing temperature on hydration process, pore structure of cementite materials and its mechanism. The result show that increasing curing temperature could reduce chloride diffusion coefficient of concrete. However, it has negative effect on the hydration degree and pore structure distribution of concrete cementitious materials when the curing temperature exceeds 60℃. Function model between equivalent age and chloride diffusion coefficient of concrete is established. It can be used to predict the movement and installation time of precast concrete members under chlorine environment, and has achieved good results in engineering application.
作者
刘虎军
杨海成
于方
谭昱
Liu Hujun;Yang Haicheng;Yu Fang;Tan Yu(CCCC Fourth Harbor Engineering Instiute Co.Ltd,Souhern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Guangzhou 510230,China;Zhejang Zhoushan North Channel Co.Ltd,Zhoushan 316000,China)
出处
《建筑科学》
CSCD
北大核心
2022年第7期120-126,共7页
Building Science
基金
浙江省交通运输厅科技项目(2018035)
南方海洋科学与工程广东省实验室(珠海)河口海岸与岛礁工程创新团队建设项目(311020009)。
关键词
混凝土
等效龄期
氯离子扩散系数
养护温度
微观机理
concrete
equivalent age
chloride diffusion coefficient
curing temperature
microcosmic mechanism
