基于钢筋加速非均匀锈蚀的混凝土保护层胀裂预测  

Prediction of concrete cover cracking based on accelerated non-uniform corrosion of reinforcing steel bars

作　　者：董征 付传清[1] 陆晨涛 李思瑶 周建波 DONG Zheng;FU Chuanqing;LU Chentao;LI Siyao;ZHOU Jianbo(College of Civil Engineering,Zhejiang University of Technology,Hangzhou 310023,China)

机构地区：[1]浙江工业大学土木工程学院,浙江杭州

出　　处：《西安建筑科技大学学报（自然科学版）》2023年第4期598-606,共9页Journal of Xi'an University of Architecture & Technology(Natural Science Edition)

基　　金：浙江省自然科学基金资助项目(LZ20E080003,LR21E080002,LQ22E080017),国家自然科学基金资助项目(51978620,52208294)。

摘　　要：自然侵蚀条件下混凝土中钢筋的腐蚀形态为非均匀锈蚀.通过有限元模拟通电加速非均匀锈蚀试验,得到钢筋表面的电流密度分布,进而推导了锈蚀过程中钢筋锈层厚度非均匀分布及其对应的钢筋表面径向位移表达式.基于锈蚀产物的非均匀锈胀位移,建立混凝土保护层胀裂模型并通过锈蚀试验验证了模型准确性.基于保护层胀裂模型,探明了锈蚀方法(均匀或非均匀锈蚀)、钢筋位置、钢筋直径和保护层厚度等关键参数对混凝土胀裂全过程的应变场以及开裂模式的影响规律.结果表明:混凝土开裂前应变场的分布规律与开裂后裂缝的位置和发展规律具有一定相关性;均匀与非均匀锈蚀条件下,混凝土应变场分布和开裂模式存在显著差异;非均匀锈蚀下,钢筋位于角部位置、钢筋直径增大、保护层厚度减小均对裂缝的发展有加剧作用.The corrosion pattern of steel bars in concrete under natural corrosive environment is non-uniform corrosion.In this study,the current density distribution on the surface of the steel bar was obtained by finite element simulation of the accelerated non-uniform corrosion test,and then the non-uniform distribution of the thickness of the steel bar rust layer during the corrosion process and the corresponding radial displacement expression of the steel bar surface were derived.On the basis of the non-uniform rust expansion displacement of the corrosion products,a model of concrete cover cracking was established.The effects of corrosion method(uniform or non-uniform corrosion),position of steel bar,diameter of steel bar,and thickness of concrete cover on the strain field and cracking mode of the concrete during rust expansion were investigated.The results show that the location and development of cracks is related to the distribution law of the strain field before the cracking of concrete.There are significant differences in the strain field distribution and cracking mode of concrete under uniform and non-uniform corrosion conditions.Under non-uniform corrosion,the position of steel bar at the corner,the increase of steel bar diameter and the decrease of protective layer thickness all aggravate the development of cracks.

关 键 词：钢筋混凝土 非均匀锈蚀 锈胀开裂 开裂模式 

分 类 号：TU375[建筑科学—结构工程] TU528