Corrosion Characteristics of Concrete Exposed to Water Environments Containing Aggressive CO2: Experimental and Numerical Study

This study aimed to investigate the corrosion characteristics of concrete exposed to water environments containing aggressive CO2. Ultrasonic velocity and quality tests were conducted to examine the deterioration law, and carbonate and microscopic testing were utilized to explore the corrosion distribution characteristics. The study determined the variation law of porosity increment caused by concrete damage evolution with soaking time and aggressive CO2 concentration. An aggressive CO2 damage model with a geometric movable boundary was established to further understand the damage evolution process of concrete with aggressive CO2. This model considers the reaction of calcium carbonate with aggressive CO2 to form calcium bicarbonate. Additionally, it includes the convection and diffusion of calcium bicarbonate under the influence of flowing water. The model was validated through carbonate tests, and its applicability was verified via engineering in situ tests. The simulation revealed the dynamic evolution of corrosion products in concrete exposed to aggressive CO2 solutions. This research contributes to the prediction of the durability of concrete structures and buildings in water environments subjected to aggressive CO2 attacks.