Evaluation of corrosion resistance of precast reinforced concrete subjected to early-age ambient pressure carbonation curing by accelerated impressed current method

In this paper, early-age ambient pressure carbonation curing was successfully developed to lower the corrosion risk by avoiding deep CO₂ penetration and preserving high pH around the steel surface. The effect of ambient pressure carbonation on the resistance of chloride-induced rebar corrosion was evaluated by applying an accelerated impressed current (IC) as a trigger. Due to improved physical properties, carbonation-cured concrete had a lowered current reading, a reduced rebar mass loss, a lessened total or free chloride content, and a decreased chloride diffusivity. Its time-to-corrosion-initiation and corrosion-propagation stages were also extended, which could strengthen the structural integrity and extend the residual service life of reinforced concrete components after corrosion initiation. Ambient pressure carbonation-cured concrete is corrosion resistant while still having the capacity to sequestrate carbon dioxide, which could contribute to the sustainability and circular carbon economy.