Numerical Simulation of Acid Gas Corroded Concrete in Industrial Environment

The neutralization model of concrete corroded by CO₂ and SO₂ coupling was established. The model considered the dissolution process of solid calcium in concrete and the expansion damage caused by sulfation products. The influence of different water-cement ratios (0.37, 0.47, 0.57) on the neutralization process of concrete was studied. The changes of neutralization degree, gas diffusion coefficient, porosity, CaCO₃ content and CaSO₄ content of corroded concrete were analyzed. The results showed that with the increase of water-cement ratio, the diffusion range of CO₂ gas in concrete gradually increased, while the diffusion range of SO₂ was almost the same. After 28 days of corrosion, with the decrease of the water-cement ratio of concrete, the decrease in porosity of concrete increased gradually, and the expansion damage in concrete with different water-cement ratios was almost the same. In the area of increasing porosity, the change trends of concrete porosity were similar. With the increase of the water-cement ratio, the length of the complete sulfation area of concrete increased, the length of the partial sulfation area decreased, and the length of the partial carbonation area of concrete gradually increased.