Experimental Study On Concrete Durability Under Carbonation And Acid Rain Corrosion

With development of industrialization, the emission of acid gas such as CO₂, SO_x, H₂S and NO_x is increasing. The acid gas which is dissolved in rainwater may result in the neutralization and deterioration of concrete structures. Recently, acid rain areas in China are expanding larger and larger and the concentration of CO₂ is getting higher and higher which make the neutralization of concrete has became one of hot spots of durability research. So this research has important practical significance.The mechanism of concrete carbonation has been analyzed as well as the mechanism of acid rain corrosion. On this basis, the corrosion mechanism of concrete under carbonation and acid rain effect together has been researched combined with actual environment, which shows that corrosion of concrete is the combined effect of H⁺, SO₄^- and CO₂. The neutralization of concrete mainly is brought by carbonation. According to the constituent and concentration of acid rain, the test of concrete durability under carbonation and acid rain corrosion together was carried out which adopted the experimental method of carbonizing and acid rain eroding alternately. The changing disciplinarian of quality, neutralization depth and compressive strength of concrete on the influence of time, corrosion environment and fly ash proportion has been researched. The experiment results show that, it suppress to concrete neutralization certainly when carbonation and acid rain corrosion effect together and adding of fly ash is disadvantageous to improve carbonation and acid rain resistance of concrete.