应力作用下混凝土胀裂前钢筋锈蚀率预测模型  

Prediction model for corrosion of steel bars in concrete under stress before corrosion cracking

作　　者：曾严红[1,2] 

机构地区：[1]上海市建筑科学研究院,上海200032 [2]上海市工程结构新技术重点实验室,上海200032

出　　处：《河北工程大学学报（自然科学版）》2012年第2期11-15,共5页Journal of Hebei University of Engineering:Natural Science Edition

摘　　要：假设混凝土保护层完全碳化时钢筋开始锈蚀,利用应力状态下混凝土碳化模型,获得应力状态下混凝土中钢筋开始锈蚀时间的计算模型。根据应力状态下混凝土中CO2有效扩散系数得到相应的O2有效扩散系数,并通过外加电流加速锈蚀试验研究了应力状态对钢筋锈蚀速率的影响。最终基于法拉第定律建立了应力状态下混凝土中钢筋锈蚀率的预测模型,并用预测模型计算工程实例。计算结果与实测结果符合较好,同时证明随着应力水平的提高,钢筋开始锈蚀时间提前,锈蚀率加快,最终导致高应力区域锈蚀率明显高于低应力区域。It was supposed that steel bars in concrete begin to corrode when concrete cover is entirely carbonized, and the time of corrosion initiation was calculated by carbonation model of concrete under stress proposed through test study. Diffusion coefficient of O2 was educed with diffusion coefficient of CO2 in concrete under stress. The effect of stress on corrosion rate of the steel bar was confirmed by experiment study. Based on the theory of corrosion electrochemistry, prediction model for corrosion of steel bars in concrete under stress before corrosion cracking was presented. The computation model was well verified by a practical engineering project. Significantly severer reinforcement was observed in higher stress concrete zone. It can be contributed to earlier corrosion initiation time and higher corrosion rate for steel bars in concrete under stress.

关 键 词：锈蚀模型 应力 电化学 混凝土结构 

分 类 号：TU528.571[建筑科学—建筑技术科学]