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

Abstract

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.