Applicability of seawater as a mixing and curing agent in 4-year-old concrete

In certain scenarios, seawater may be the only mixing/curing agent available; hence, it is necessary to optimize conditions for its application in concrete structures. In this study, the applicability of seawater as a mixing and curing agent in 4-year-old mortar cement specimens is evaluated. Unlike previous studies, we focused on evaluating the long-term performance of reinforced mortar specimens exposed to seawater. Specimens comprised ordinary Portland cement (OPC), grand granulated blast furnace slag (GGBFS), and reinforced concrete with plain steel, epoxy-coated, or stainless-steel bars; they were subjected to wetting-drying cycles (mimicked for tidal/splash zones) in the laboratory, and the corrosion was evaluated through electrochemical techniques. The results indicate that the effect of seawater on corrosion activity is considerably higher as a curing agent than that as a mixing agent. Further, GGBFS exhibited better performance than OPC; similarly, epoxy-coated and stainless-steel bars exhibited better corrosion resistance than plain steel bars. The results obtained in this study highlight the need to study the application of seawater in concrete mixing. (C) 2020 Elsevier Ltd. All rights reserved.