Corrosion-induced bond degradation in sustainable one-part alkali-activated reinforced concrete for durable infrastructure

The performance of reinforced concrete depends on the bond between steel reinforcement and concrete, which deteriorates under corrosion, affecting load transfer and structural integrity. This study investigates the bond behaviour of one-part alkali-activated concrete (OPAAC) - a low-carbon alternative to ordinary Portland cement concrete (OPCC) under accelerated corrosion. Corrosion potential (E corr ) was monitored using a GECOR system, and pull-out tests on rebars of five diameters (10–25 mm) before and after 3–9 days of corrosion exposure evaluated residual bond strength. Results show that although corrosion reduced bond strength in both concretes, OPAAC exhibited slower deterioration and superior bond retention. Larger rebars (25 mm) retained the highest residual bond capacity. OPAAC demonstrated up to 60% higher bond strength in rebars ≤ 20 mm and up to 73% higher in 25 mm rebars compared to OPCC. A strong correlation between corrosion percentage and residual bond strength was established, confirming OPAAC’s potential for improved durability, extended service life, and sustainable construction.