Effects of Chloride and Sulfate Salts on Corrosion Behavior of Reinforced Bar in Simulated Concrete Pore Solution

The effects of NaCl, NH₄Cl, Na₂SO₄ and (NH₄)₂SO₄ on the corrosion behavior of reinforced bar (Q345B carbon steel) in simulated concrete pore fluid were studied by electrochemical test and corrosion morphology observation. The results show that Cl^- was more likely to cause pitting on the surface of carbon steel than SO₄^2-, and NH₄⁺ was more aggressive, which could greatly increase the corrosion rate of carbon steel. The destructive ability of the four salts to carbon steel from strong to weak was as follows: (NH₄)₂SO₄ > NH₄Cl > NaCl > Na₂SO₄. Increasing temperature could exacerbate the corrosion of carbon steel, which could also be confirmed by the results of corrosion activation energy.