Carbonation-Induced Corrosion on Concrete with Waste Brick Powder and Hydrated Lime Additive

This study explores the possibility of partially replacing cement with crushed brick powder (CBP) and 6% hydrated lime (HL) in concrete. The results showed an increase in compressive strength compared with the control at the intermediate age of 56 days. Adding HL to the cement and CBP paste samples resulted in a 22% reduction in capillary pores and a 23% increase in gel pores. Although the control samples had less carbonation penetration, the corrosion rate was higher than that of blended cement concrete with HL. The half -cell potential measurement on carbonated samples indicated that, unlike chloride -induced corrosion, the depassivation of steel could not be identified by a stable demarcating half -cell potential value. Moreover, blended cement concrete with HL exhibited higher resistivity. Visual inspection of corroded bars revealed that the assumption of uniform corrosion by carbonation might not be entirely accurate. The use of HL with a cement-CBP binder improved the concrete's 's characteristics and reduced the risk of carbonation -induced corrosion. The study provides supplementary information on the feasibility of using a blend of crushed brick powder and hydrated lime as sustainable alternatives in the field of concrete construction with environmental considerations.