%0 Journal Article
%T Influence of Simulated Acid Rain Corrosion on the Uniaxial Tensile Mechanical Properties of Concrete
%A Ying-zi Zhang
%A Ying-fang Fan
%A Hong-nan Li
%J International Journal of Corrosion
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/172394
%X An experimental study on the uniaxial tensile property of concrete exposed to the acid rain environment was carried out. Acid rain with pH level of 1.0 was deposed by the mixture of sulfate and nitric acid solution in the laboratory. Dumbbell-shaped concrete specimens were immersed in the simulated acid rain completely. After being exposed to the deposed mixture for a certain period, uniaxial tensile test was performed on the concrete specimens. The results indicate that elastic modulus, tensile strength, and peak strain have a slight increase at the initial corrosion stage, and with the extension of corrosion process, elastic modulus and tensile strength decrease gradually, while the peak strain still increases. It is found that the compressive strength is more sensitive than the tensile strength in aggressive environment. Based on the experimental results, an equation was proposed to describe the ascending branch of the stress-strain curve of the concrete corroded by acid rain. 1. Introduction Acid rain has become an issue of widespread concern in Asia, and it was first recognized as a potential environmental pollution problem in the late 1970s and early 1980s. It was also an increasing problem in China during the last decades [1¨C4]; one third of China¡¯s land mass was affected by acid rain. The acid rain is composed of acid substances, such as H2SO4, HCl, and HNO3, which readily react with Ca(OH)2 and form CaSO4¡¤2H2O, Ca(NO3)2¡¤4H2O, and CaCl2¡¤6H2O. Because the solubility of these products is higher than that of CaCO3, which is formed at the surface by the reaction of Ca(OH)2 with CO2 (carbonation), they are dissolved in rainwater and penetrate into the inner pores of concrete. After the evaporation of rainwater, these salts redeposit and give rise to stress in the concrete structure, resulting in cracking, mass loss, and eventually structural failure. In the early 1950s, US Environmental Protection Agency reported that the cost of repairing or replacing the concrete structure every year due to acid rain in the United States was more than $5 billion dollars. In Britain, the economic loss due to acid rain was 0.15% of the GNP. Guo [5] in 2001 estimated that the direct material loss due to acid rain only in Guangzhou was 1.2 billion Chinese Yuan. Although some ways have been used to reduce acid rain, the acid rain region in China even continue to expand, therefore, the property of the corroded concrete have become to be a critical issue and attracted a lot of researchers worldwide [6¨C12]. However, due to the complicated mechanism, there remains only very
%U http://www.hindawi.com/journals/ijc/2012/172394/