The Effect of Sea Water in The Curing Time of The Strength and Concrete Durability with Variation of Cement Water Factors

Abstract

The use of seawater for curing concrete is a practice considered in coastal regions due to its availability, but its impact on long-term performance remains a significant concern. This research investigates the effect of seawater curing on the mechanical strength and durability of concrete, specifically analyzing its interaction with varying water-cement ($w/c$) ratios. Concrete specimens were prepared with multiple $w/c$ ratios and subjected to two distinct curing regimes: immersion in potable water (control) and immersion in seawater. The development of compressive strength was systematically tested at different curing times (e.g., 7, 14, and 28 days). Durability performance was evaluated through key indicators, primarily Rapid Chloride Permeability Tests (RCPT) and water absorption, to assess the resistance to chloride ingress. The results demonstrate that while seawater curing may slightly accelerate early-age strength gain, it has a significant detrimental impact on long-term durability. Specimens cured in seawater exhibited substantially higher chloride ion permeability compared to the control group, an effect that was exacerbated at higher $w/c$ ratios. This indicates a compromised microstructure and a significantly increased risk of chloride-induced reinforcement corrosion. This study concludes that the use of seawater for curing concrete, especially for reinforced structures, is not advisable as it severely compromises its durability.