基于初始缺陷形状的混凝土结构锈胀开裂理论模型  

Theoretical Model of Rust Expansion Cracking of Concrete Structure Based on the Initial Defect Shape

作　　者：伦培元 张小刚 张强[2] 赵然 LUN Pei-yuan;ZHANG Xiao-gang;ZHANG Qiang;ZHAO Ran(School of Civil Engineering,Central South University,Changsha 410075,China;College of Architecture and Civil Engineering,Beijing University of Technology,Beijing 100022,China;School of Civil and Traffic Engineering,Shenzhen University,Shenzhen 518060,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]北京工业大学建筑工程学院,北京100022 [3]深圳大学土木与交通工程学院,深圳518060

出　　处：《东北大学学报（自然科学版）》2020年第7期1020-1026,共7页Journal of Northeastern University(Natural Science)

基　　金：国家自然科学基金资助项目(51908009,51738001,51878413);深圳市科技计划项目(JCYJ20190808112019066).

摘　　要：为考虑材料初始缺陷形状的影响,将其假定为三维半椭球形.基于断裂力学理论将锈胀裂缝扩展过程划分为两个临界阶段:初始开裂阶段和完全开裂阶段,并分别对两组临界阶段进行了分析,建立了混凝土构件保护层胀裂时的锈胀力及开裂时间预测模型.为了验证所提出预测模型的正确性,分别采用已有的室内锈蚀实验、现场测试数据进行验证,计算结果吻合较好,说明本文预测模型具有一定合理性.在此基础上,对初始缺陷长度、混凝土保护层厚度、钢筋半径、相对保护层厚度等参数进行敏感性分析,结果表明增加混凝土保护层厚度和相对保护层厚度,有利于提高钢筋混凝土结构的服役性能.In order to consider the influence of the initial defect shape of materials,it was assumed to be a three-dimensional semi-ellipse.Based on the theory of fracture mechanics,the expansion process of the rust expansion cracking can be divided as two critical stages:the initial cracking stage and the complete cracking stage,which were both analyzed.A prediction model of rust expansion force and cracking time was established when concrete cover cracks.The proposed model was verified using the pre-existing indoor corrosion test and field test data,and the results showed that the prediction model is reasonable.On this basis,parameter sensitivity analyses,such as the length of the initial defect,the concrete cover thickness,the reinforcing bar radius,the relative cover thickness were analyzed,the results showed that the service performance of RC structures can be improved by increasing the concrete cover thickness and the relative cover thickness.

关 键 词：钢筋锈蚀 初始缺陷形状 临界锈胀力 开裂时间 耐久性 

分 类 号：TU375[建筑科学—结构工程]