The Effect of Corrosion on the Mechanical Properties (Diameter, Cross-Sectional Area, Weight) of the Reinforcing Steel

Corrosion of steel reinforcement is a major cause of deterioration in reinforced concrete structures, especially those located in marine environments. This study experimentally investigates the influence of corrosion on bond strength between reinforcing steel and concrete, as well as the effect on steel bar properties. Thirty-six concrete cubes reinforced with 12mm steel bars were prepared and subjected to varying corrosion conditions - non-corroded control, uncoated corroded, and coated with Anogeissus leiocarpus exudate. Specimens were immersed in 5% NaCl solution to accelerate corrosion, and tested at intervals up to 360 days. Pull-out tests showed bond strengths of corroded bars reduced by 25-30% compared to non-corroded controls. In severe cases, complete bond failure occurred in corroded specimens. Corrosion also led to reductions in bar diameter (0.04-0.05mm), cross-sectional area (0.5-1.3%), and weight (0.006-0.009kg) over time. Natural exudate coatings on steel mitigated these effects, restoring bond strength and limiting reductions to 0.01-0.02mm in diameter, and 0.003-0.005kg in weight. Graphical analysis correlated well with test data, clearly portraying deterioration trends under corrosion exposure. This study concludes corrosion causes significant weakening of bond integrity and property losses in reinforcement. Natural exudate coatings were found to effectively inhibit corrosion activity by restoring bond strength and protecting steel bars. With proper application, such eco-friendly coatings show promise as sustainable corrosion prevention alternatives for reinforced concrete infrastructure, especially in marine environments where corrosion accelerates more rapidly.