Influencing factors on critical chloride content for corrosion of reinforcing steel embedded in concrete

The critical chloride content for corrosion of the reinforcing steel embedded in concrete is essential to determine the service life of RC structures exposed to chloride environment. However, it may be influenced by several factors such as type of reinforcing steel, water/cement (W/C) ratio, cement types, test methods, and environmental conditions, etc. Thus, this study is aimed to investigate the influence of W/C ratio and accelerated corrosion test method on the critical chloride content for corrosion of the reinforcing steel embedded in concrete. For this purpose, lollypop and prism concrete test specimens were made for W/C ratios of 31%, 42%, and 50%, and then the accelerated corrosion tests were conducted by electrochemical and cyclic wet and dry seawater method. During the test, corrosion monitoring by half cell potential method was carried out to detect the time to initiation of corrosion for test specimens and its chloride content was evaluated by breaking the concrete test specimens when corrosion of the reinforcing steel embedded in concrete was perceived. It was observed from the test results that the critical chloride content of the specimens used in the study would be dependent on both W/C ratio and the accelerated corrosion test methods, and they were found to range from 0.91 to 1.63 kg/m³.