Eco-Friendly Corrosion Inhibition and Strength Improvement of Concrete Using Agricultural Waste–Derived Mango Leaf Extract

Embedded steel reinforcement corrosion has been a significant source of reinforcement loss in reinforced concrete (RC) constructions and is specifically prevalent in chloride containing and chemically aggressive environments. Traditional corrosion inhibitors albeit effective are normally synthetic and costly and pose health threats to the environment. The paper examines the use of mango leaf extract as a by-product of agriculture waste that contains polyphenols and tannin as sustainable and eco-friendly corrosion inhibitor in M25-grade concrete. It was used as extract at 0, 1, 2, and 3 percent doses and its effect on the compressive strength, split tensile, flexural and durability (loss of weight in the presence of chemicals) was observed after 7, 14 and 28 days. Results show that, 1-2% extract significantly increases mechanical performance, whereby the maximum compressive strength (34.2 N/mm2), split tensile strength (3.10 N/mm2), and flexural strength (6.1 N/mm2) are recorded at 2 percent dosage. Durability results showed reduced weight loss, indicating improved resistance to aggressive environmental conditions. The results show that mango leaf extract could serve as a cost-effective and sustainable alternative to conventional chemical inhibitors, adding to the longevity and durability of RC structures and contributing to the principles of the circular economy.