Investigation on the Use of Seawater for Making and Curing Unreinforced Concrete

As the global population expands and infrastructure demands rise, sustainable water management practices become more imperative. Meanwhile, global freshwater scarcity has been aggravated by conventional concrete production methods. In this case, seawater presents a promising alternative due to its abundance. Currently, it is prohibited to use seawater in reinforced concrete according to industry regulations due to its corrosive nature. Therefore, this study investigates the viability of utilizing seawater for both the mixing and curing of unreinforced concrete. The experimental study has mainly focused on the effect of seawater on curing unreinforced concrete and the effect of seawater on both making and curing unreinforced concrete comparing the properties of fresh concrete (slump, slump loss) and mechanical properties of hardened concrete (compressive strength, splitting tensile strength, drying shrinkage). Findings reveal that while seawater mixing exerts an insignificant impact on the slump but induces increased slump loss, seawater curing also demonstrates an insignificant effect on hardened concrete properties. Moreover, mechanical performance displays notable variation between seawater and freshwater concrete. Based on the results the paper concludes that the use of seawater for curing unreinforced concrete is recommended. Finally, some other recommendations for further studies are also provided based on laboratory trials.