National Core Research Center for Disaster-Free and Safe Ocean Cities Construction, Dong-A University, Busan 49315, Korea.
Department of ICT Integrated Ocean Smart Cities Engineering, Dong-A University, Busan 49315, Korea.
Sensors (Basel). 2021 Sep 19;21(18):6287. doi: 10.3390/s21186287.
The primary purposes of this study are to investigate the feasibility of electrochemical deposition treatment (EDT) as a comprehensive rehabilitation method for corrosion-induced deterioration in reinforced concrete with various severity levels, and to propose a guideline for the determination of critical factors to advance EDT. This study includes three experimental phases, each of which simulates the initiation (de-passivation), propagation (high corrosion activity), and acceleration (formation of a surface-breaking crack) periods of corrosion-induced deterioration. After completion of a series of accelerated corrosion tests, damaged concrete samples with different severity levels are rehabilitated by a series of EDT processes using a MgCl solution in an electrolyte. The main variables for this experiment are the concentration levels (0, 0.3, 1.0 and 3.0 M) of a MgCl solution for test phase 1, charging time (0, 2, and 7 days) in EDT for test phase 2, and configuration of pre- and post-treatment processes in EDT for test phase 3. The rehabilitation performance of EDT is evaluated by analyzing the AC impedance properties of the steel-and-concrete interface using electrochemical impedance spectroscopy (EIS) for the test phases 1 and 2, and microscopic alternation in concrete cracks using optical microscopic image and SEM/EDX. It is demonstrated that EDT is an effective method for preventing and mitigating corrosion-induced deterioration in the initiation and rust propagation periods of corrosion and for repairing (closing and filling) a corrosion-induced surface-breaking crack in the acceleration phase of corrosion. Corrosion-resistant performance of concrete increases as the concentration levels of a MgCl solution in an electrolyte increases and as the charging time in EDT increases. In addition, a post-treatment process (applying a NaOH solution) after the electrochemical deposition process significantly improves crack-repairing performance of EDT.
本研究的主要目的是探讨电化学沉积处理（EDT）作为一种全面的修复方法，用于处理不同严重程度的腐蚀引起的钢筋混凝土劣化，并提出确定关键因素以推进 EDT 的指南。本研究包括三个实验阶段，每个阶段模拟腐蚀劣化的起始（去钝化）、扩展（高腐蚀活性）和加速（表面贯穿裂缝形成）阶段。在完成一系列加速腐蚀试验后，使用电解质中的 MgCl 溶液对具有不同严重程度的受损混凝土样品进行一系列 EDT 处理以进行修复。该实验的主要变量是：测试阶段 1 中 MgCl 溶液的浓度水平（0、0.3、1.0 和 3.0 M）、EDT 中的充电时间（0、2 和 7 天）、以及测试阶段 3 中 EDT 前后预处理过程的配置。通过电化学阻抗谱（EIS）分析钢-混凝土界面的交流阻抗特性来评估 EDT 的修复性能，用于测试阶段 1 和 2，以及通过光学显微镜图像和 SEM/EDX 分析混凝土裂缝的微观变化来评估。结果表明，EDT 是一种有效的方法，可用于防止和减轻腐蚀起始和锈扩展阶段的腐蚀引起的劣化，并修复（闭合和填充）腐蚀加速阶段的腐蚀引起的表面贯穿裂缝。随着电解质中 MgCl 溶液浓度的增加和 EDT 中充电时间的增加，混凝土的耐腐蚀性能提高。此外，电化学沉积处理后进行后处理过程（施加 NaOH 溶液）显著提高了 EDT 的裂缝修复性能。
