持续高温条件下重混凝土劣化行为研究  

Study on deterioration behavior of heavy concrete under continuous high temperature conditions

作　　者：陈森 李浩 王振 张昆桥 张文斌 罗华清 张伟 CHEN Sen;LI Hao;WANG Zhen;ZHANG Kunqiao;ZHANG Wenbin;LUO Huaqing;ZHANG Wei(China Nuclear Power Operation Technology Co.,Ltd.,Wuhan 430000,China)

机构地区：[1]中核武汉核电运行技术股份有限公司,湖北武汉430000

出　　处：《混凝土与水泥制品》2023年第11期22-25,35,共5页China Concrete and Cement Products

基　　金：国家重点研发计划项目(2019YFB1900903)。

摘　　要：研究了温度(25~400℃)与高温持续时间(0.5~30 d)耦合作用下重混凝土力学性能的变化规律,并结合微观测试分析了其影响机理。结果表明:当温度不高于80℃时,随着温度与高温持续时间的增加,重混凝土的力学性能略有提高;当温度高于300℃时,重混凝土的质量损失随着温度与高温持续时间的增加呈增大趋势,力学性能显著降低,重混凝土中的结合水、AFt、C-S-H等水化产物逐渐分解,内部有害孔比例增加;基于试验结果建立的温度和高温持续时间耦合作用下重混凝土的本构模型可以预测持续高温条件下重混凝土的力学性能。The change rule of mechanical properties of heavy concrete under the coupling action of temperature(25~400℃)and high temperature duration(0.5~30 d)was studied,and its influence mechanism was analyzed based on microscopic testing.The results show that when the temperature is not higher than 80℃,the mechanical properties of heavy concrete slightly improve with the increase of temperature and high temperature duration.When the temperature is higher than 300℃,the mass loss of heavy concrete increases with the increase of temperature and high temperature duration,and the mechanical properties significant decrease.The hydration products such as bound water,AFt,C-S-H,etc.in the heavy concrete gradually decompose,and the proportion of harmful pores inside increases.Based on the experimental results,the established constitutive model of heavy concrete under the coupling effect of temperature and high temperature duration can predict the mechanical properties of heavy concrete under continuous high temperature conditions.

关 键 词：重混凝土 微观结构 高温劣化 力学性能 本构模型 

分 类 号：TU528.19[建筑科学—建筑技术科学]