Experimental study demonstrates reduced steel corrosion in precast reinforced concrete following rapid surface carbonation, suggesting a method to boost durability.
Key Points
To evaluate the impact of induced rapid surface carbonation (IRS-C) treatment on the corrosion resistance of precast reinforced concrete elements and identify the protective mechanisms involved.
Treated hardened concrete specimens—comprising 12 beams (8 reinforced, 4 unreinforced) and 12 cylinders—in a CO2 vacuum chamber for 48 hours, keeping half untreated as controls.
Evaluated corrosion and transport properties using ASTM G109 testing, phenolphthalein pH testing, water absorption testing, and chloride titration.
ASTM G109 testing demonstrated lower total corrosion in IRS-C treated reinforced concrete specimens relative to untreated reference controls.
Phenolphthalein tests confirmed the treatment did not reduce the pH near the steel reinforcement or lower the critical chloride threshold required for corrosion onset.
Water absorption and titration analyses revealed the formation of a low-porosity outer surface layer that decreased both water ingress and chloride penetration.