The Effects of Salt Water on Concrete: A Case Study of the Atlantic Ocean

Abstract

This study investigates the effects of saltwater exposure on the compressive strength and durability of concrete, particularly in marine environments. Concrete specimens prepared with both fresh and saltwater in a 1:2:4 mix using a water-cement ratio of 0.5 and were tested at 7, 21, and 28 days. Samples were cured in water tanks at room temperature for 28 days. Compressive strength tests were conducted using a 2000 kN universal testing machine according to BS EN 12390-3:2019. Microscopic analysis revealed microstructural degradation such as salt crystal deposits and microcracks. Three cubes per sample were cast and the average values gotten. Microscopic analysis highlighted saltwater's impact on the concrete’s microstructure. Concrete cubes were cast and cured under different water conditions, including freshwater, saltwater and Sodium Chloride (NaCl) solutions, with compressive strength tested at 7, 21, and 28 days. This process provided comparative insights into the effects of chloride and sulfate ions on the structural performance and durability of concrete. Results showed that exposure of concrete to saltwater reduced compressive strength, facilitating chloride ingress and accelerating reinforcement corrosion. Microstructural analysis identified salt crystals and microcracks as key contributors to degradation, highlighting the detrimental long-term effects on concrete durability. The results obtained from the experiment also highlight the influence of different curing environments on concrete compressive strength. Concrete cast and cured in fresh water displayed consistent strength development, reaching 25.12 N/mm² at 28 days. In contrast, concrete cast using salt water and cured in fresh water showed lower strength but reached 20.46 N/mm² at 28 days. Concrete cast in fresh water and cured in seawater demonstrated the highest strength at 28 days (26.63 N/mm²), suggesting a potential enhancement in curing efficiency. However, samples cast in fresh water and cured with NaCl had a lower strength of 22.68 N/mm².