Abstract

The reduction in service-life of reinforced concrete structures caused by corrosion of reinforcing steel is a major problem to the construction industry. The use of specialty steels is one of the strategies suggested to minimize this deterioration phenomenon. In this study, the corrosion-resistance of epoxy-coated and selected specialty steel bars embedded in concrete and exposed to chloride environment was evaluated. The specialty bars considered included two types of epoxy-coated bars with varying degrees of damage, stainless steel bars, stainless clad bars, and a low-carbon chromium steel bar. The corrosion resistance of the investigated reinforcing bars was investigated by measuring corrosion potentials and corrosion current density over a period of about 32 months. As expected, the corrosion resistance of specialty bars was better than that of the black (normal) bars. The corrosion resistance of the epoxy-coated bars decreased with the degree of surface damage. Further, the corrosion-resistance of epoxy-coated bars with up to 1% damage was better than that of the other specialty bars. Additionally, the low corrosion rate noted in the epoxy-coated bars suggests longer service-life of structures built with these bars compared to structures incorporating specialty steel bars considered in the study. The relatively low initial cost of epoxy-coated bars, compared to other specialty steel bars, and their longer life results in a considerable cost saving. Also, the decreased corrosion damage of concrete results in technical (long service-life and safety), environmental (aesthetics) and economic (less overall cost of construction) benefits.

摘要

钢筋锈蚀导致钢筋混凝土结构使用寿命降低是建筑行业面临的主要问题。使用特种钢是建议尽量减少这种劣化现象的策略之一。在这项研究中，评估了嵌入混凝土中并暴露于氯化物环境中的环氧树脂涂层和选定的特种钢筋的耐腐蚀性。考虑的特种钢筋包括两种类型的具有不同损坏程度的环氧树脂涂层钢筋，不锈钢钢筋、不锈钢复合钢筋和低碳铬钢筋。通过在大约 32 个月的时间内测量腐蚀电位和腐蚀电流密度来研究所研究钢筋的耐腐蚀性。正如预期的那样，特种棒材的耐腐蚀性优于黑色（普通）棒材。环氧涂层棒材的耐腐蚀性随着表面损伤程度的增加而降低。此外，损伤高达 1% 的环氧涂层棒材的耐腐蚀性优于其他特种棒材。此外，环氧树脂涂层钢筋的低腐蚀率表明，与研究中考虑的特殊钢筋结构相比，用这些钢筋建造的结构的使用寿命更长。与其他特种钢筋相比，环氧树脂涂层钢筋的初始成本相对较低，而且使用寿命更长，因此可以节省大量成本。此外，混凝土的腐蚀损伤减少导致技术（长使用寿命和安全性），