EFFECT OF SALT WATER ON CONCRETE USED FOR BUILDING CONSTRUCTION IN NIGERIA: (A CASE STUDY OF BADAGRY LAGOS)

ABSTRACT This study investigates the impact of saline water, specifically ocean water, on the compressive strength of mass concrete structures in waterlogged areas. The research employs both primary and secondary data, including a review of existing literature and laboratory experiments. A systematic methodology was developed, where concrete cubes were cast and cured using two different water types: saline water (ocean water) and potable water (fresh water) serving as the control mix. The concrete was tested for compressive strength at various intervals (7, 14, 21, and 28 days) using standardized procedures. Electrical conductivity and chloride content of the saline water were analyzed to assess salinity levels, revealing a conductivity of 11170 µS/cm and a salinity of 1782 mg/L. Results indicated that the concrete samples mixed with saline water exhibited higher early compressive strength (14.15 N/mm² at 7 days) compared to those mixed with potable water (10.35 N/mm²). However, the strength of the saline water samples began to decline after 14 days, reaching 11.95 N/mm² by day 28, while the potable water samples demonstrated consistent strength growth, achieving 13.55 N/mm². These findings suggest that while saline water can accelerate early hydration and strength development, its long-term effects are detrimental to concrete durability. Therefore, the use of potable water is recommended for concrete structures to ensure their longevity and structural integrity, particularly in coastal environments where saline exposure is prevalent.