Corrosion and Bond Strength Behaviour of Fly Ash-Based Lateritic Self-Compacting Concrete

Infrastructure development is crucial in densely populated countries like India, which leads to high demand for construction materials such as cement and aggregate. The production of these materials is energy-intensive and has adverse effects on the environment. Sustainable construction aims to reduce energy and resource usage while maintaining the strength and durability of the concrete. Using supplementary materials in concrete to replace cement and aggregate is essential. In this study, trial mixes were prepared to determine the optimal water-to-cement ratio based on fresh concrete properties like filling ability, passing ability, segregation resistance and viscosity. Cement was then partially replaced with fly ash (FA) at 10% up to 40% intervals. The FA mix was further optimized by replacing natural fine aggregate (NFA) with processed laterite fine aggregate (PLFA) at 10%, 20%, 30% and 40% to measure corrosion and bond strength properties. To conduct the testing, 150 mm cubes with centrally inserted 16 mm diameter High Yield Strength Deformed (HYSD) rebars were cast and cured in water diluted with 3.5% sodium chloride (NaCl) to maintain the marine environment for up to 120 days. Electrochemical tests were performed to measure corrosion properties, including Open Circuit Potential (OCP) and Tafel Plot Corrosion tests. As the corrosion tests are non-destructive, the same specimens were used for pull-out tests to measure the bond strength properties of the specimen.