Multi-species reactive transport modeling of electrochemical corrosion control in saturated concrete structures including electrode reactions and thermodynamic equilibrium
Multi-species reactive transport modeling of electrochemical corrosion control in saturated concrete structures including electrode reactions and thermodynamic equilibrium
复制标题
饱和混凝土结构中电化学腐蚀控制的多物种反应输运模型，包括电极反应和热力学平衡
DOI：
10.1016/j.conbuildmat.2020.122228
复制
发表时间：
2021-01-29
影响因子：
7.4
通讯作者：
Ou, Jinping
中科院分区：
文献类型：
--
作者：
Guo, Bingbing;Qiao, Guofu;Ou, Jinping
混凝土中的离子迁移决定了钢筋混凝土结构电化学腐蚀控制的有效性，如电化学氯离子萃取、电化学实现、外加电流阴极保护等。本文建立了电化学腐蚀控制下饱和混凝土结构中多组分反应输运的数值模型。该模型包括离子传递、热力学平衡和电极反应。用Tafel方程考虑了钢筋表面的电极反应。采用热力学模型来表达孔隙溶液与水化产物之间的物理化学反应。在数值模型的每个时间步结束时，更新基于孔隙率变化的材料扩散系数。另外，通过室内实验对数值模型进行了验证。数值结果清楚地表明，基于数值模型的电化学腐蚀控制能够防止腐蚀的起裂，避免氢脆，阻止Cl-渗透，提高钢筋附近的pH值和CH含量。(C) 2021 Elsevier Ltd版权所有。
The ionic migration in concrete determines the efficiency of electrochemical corrosion control of reinforced concrete structures, such as electrochemical chloride extraction, electrochemical realkalization, and impressed current cathodic protection. In this study, a numerical model of the multi-species reactive transport in saturated concrete structures with electrochemical corrosion control is proposed. The proposed model includes ionic transport, thermodynamic equilibrium and electrode reactions. The electrode reactions at the surface of reinforcing steel are considered using the Tafel equation. The thermodynamic model is adopted to express the physical and chemical reactions between pore solution and hydration products. The diffusivity coefficient of material based on the variation of porosity is updated at the end of each time step of the numerical model. Additionally, a laboratory experiment is conducted to verify the numerical model. The numerical results clearly show that the applied electrochemical corrosion control based on the numerical model is capable of preventing the initiation of corrosion, avoiding the hydrogen embrittlement, arresting the Cl- penetration, and improving the pH value and CH content adjacent to the reinforcing steel. (C) 2021 Elsevier Ltd. All rights reserved.