Influence of curing period and curing medium on corrosion, surface properties and compressive strength of concrete mixed with seawater

Water scarcity is one of the main problems faced by the world today. The Philippines is at risk of reaching the state of vulnerability in terms of the availability of freshwater. In every construction project, concrete curing is necessary. A significant amount of freshwater is needed to cure concrete. Thus, there is a need to find an alternative medium for curing concrete, such as seawater. This study reports the effects of curing period and curing medium on the concrete mixed with seawater to be able to evaluate the capability of seawater to be an alternative curing medium. The effects of seawater were determined through the corrosion, surface properties and compressive strength of the concrete mixed with seawater. The corrosion of the embedded steel bars in the rectangular specimens was tested every seven (7) days for four (4) months using the CT-7 (Corrosion Monitoring Test). The compressive strength of the cylindrical concrete specimens was evaluated using the ASTM C39 (Standard Test Method of Cylindrical Concrete Specimen). The data obtained for the surface properties were evaluated by observation. The data were interpreted by comparing the strength of the seawater cured (SWC) specimens and the freshwater cured (FWC) specimens. Curing the specimens in either freshwater or seawater does not have significant differences in either freshwater or seawater does not have significant difference in terms of its compressive strength and its corrosion current density until its 84th day. While in terms of corrosion potential, SWC specimens tend to have higher value only on the 2nd week of testing. However, from the results, it can be said that the corrosion potential on the early weeks of testing is still stabilizing. Seawater as a curing medium for CMSW can produce the same effect as freshwater curing on their 84th day, in terms of corrosion, compressive strength and surface properties, given that the specimens will only be cured for 7 days