混凝土中钢筋的腐蚀速率模型及电化学参数分析  

Analysis of electrochemical parameters and corroion rate model for steel rebar in concrete

作　　者：余波[1,2] 毋铭 詹雷颖 

机构地区：[1]广西大学土木建筑工程学院工程防灾与结构安全教育部重点实验室,广西南宁530004 [2]新加坡南洋理工大学土木与环境工程学院,新加坡639798

出　　处：《混凝土》2015年第8期20-25,共6页Concrete

基　　金：国家自然科学基金项目(51168003);广西自然科学基金重大项目(2012GXNSFEA053002);广西自然科学青年基金项目(2013GXNSFBA019237);广西科学研究与技术开发项目(桂科攻1377001-11)

摘　　要：混凝土中钢筋的腐蚀机制复杂,且涉及的电化学参数较多。基于钢筋腐蚀的电化学原理,结合混凝土中钢筋的宏电池腐蚀模型,定量分析了各种电化学参数对钢筋腐蚀电位、腐蚀电流密度和腐蚀速率的影响规律,并揭示了电化学参数对钢筋腐蚀行为和腐蚀速率的影响机理。分析表明,随着阳极(或阴极)塔菲尔斜率的增大(或减小),阴阳极之间的腐蚀电位差和腐蚀电流密度均逐渐减小;随着阴极和阳极交换电流密度的增大,净反应速度越大,导致阴阳极之间的腐蚀电位差和腐蚀电流密度均略有增加;随着阳极(或阴极)平衡电位的增大(或减小),阳极的还原性或阴极的氧化性降低,钢筋腐蚀速率逐渐减小;总体而言,阴极塔菲尔斜率和阳极平衡电位对钢筋腐蚀速率的影响较为显著,而其他参数的影响相对较小。Corrosion mechanism of steel rebar in concrete is complex, which involves lots of electrochemical parameters. Based on electrochemical principle and macro - cell corrosion model for steel rebar in concrete, the influences of electrochemical parameters on corrosion potential, corrosion current density and corrosion rate were analyzed. Moreover, influences of electrochemical parameters on corrosion mechanism and corrosion rate of steel rebar in concrete were also discussed.Analysis results show that corrosion potential difference and corrosion current density decrease with the increase of anodic Tafel slope or decrease of cathodic Tafel slope.Increase of anodic/ca- thodic exchange current density results in a minor increase in potential difference between anode and cathode as well as corrosion current densities due to the net reaction rate grows.Corrosion rate decreases with increase of anodic equilibrium potential or decrease of ca- thodic equilibrium potential since anode reduction or cathode oxidizability attenuates. Cathodic Tafel slope and anodic equilibrium poten- tial have a relative significant effect on corrosion rate,while the other parameters do not affect corrosion rate obviously.

关 键 词：钢筋混凝土 腐蚀速率 宏电池腐蚀模型 电化学参数 敏感性分析 

分 类 号：TU528.01[建筑科学—建筑技术科学]