Saura Pascual, Zornoza Emilio, Andrade Carmen, Ferrandiz-Mas Verónica, Garcés Pedro
Department of Architectonical Constructions, University of Alicante, San Vicente, 03690 Alicante, Spain.
Department of Civil Engineering, University of Alicante, San Vicente, 03690 Alicante, Spain.
Materials (Basel). 2022 Mar 17;15(6):2216. doi: 10.3390/ma15062216.
In the present work, the composition of a corroded reinforcing steel surface is studied at different pH values (related to different degrees of development in the corroding zones of the corrosion process) in solutions simulating chloride-contaminated environments. The media considered consist of saturated calcium hydroxide solutions, progressively neutralized with FeCl or by adding 0.5 M NaCl to the solution. The results found in present work confirm higher levels of acidity in the solutions with higher concentrations of Fe.In the present work, emphasis is given to the composition of the oxides in solutions that simulate the conditions that exist inside of a localized corrosion pit as a consequence of the reaction of chloride on reinforcing steel. The oxides were studied using Raman and XPS techniques; the results obtained with both techniques are mutually coherent. Thus, in the passive state, the oxides found are those reported previously by other authors, while in the corroding state, the present results are more comprehensive because the conditions tested studied a variety of pore solution composition with several pH values; we tried to reproduce these values inside the pits in conditions of heavy corrosion (very acidic). The oxides found are those typically produced during iron dissolution and seem not the best route to study the corrosion process of steel in concrete; the electrochemical tests better characterize the corrosion stage.
在本研究中，在模拟受氯污染环境的溶液中，研究了不同pH值（与腐蚀过程中腐蚀区域的不同发展程度相关）下锈蚀钢筋表面的成分。所考虑的介质由饱和氢氧化钙溶液组成，通过用FeCl逐步中和或向溶液中添加0.5M NaCl来实现。本研究中发现的结果证实，Fe浓度较高的溶液中酸度更高。在本研究中，重点关注模拟因氯化物与钢筋反应而在局部腐蚀坑内存在的条件的溶液中氧化物的成分。使用拉曼和XPS技术对氧化物进行了研究；两种技术获得的结果相互一致。因此，在钝化状态下，发现的氧化物是其他作者先前报道过的那些，而在腐蚀状态下，本研究结果更全面，因为测试条件研究了具有多个pH值的各种孔隙溶液成分；我们试图在严重腐蚀（非常酸性）条件下在坑内重现这些值。发现的氧化物是铁溶解过程中通常产生的那些，似乎不是研究混凝土中钢筋腐蚀过程的最佳途径；电化学测试能更好地表征腐蚀阶段。
