Abstract
A literature review has been made with respect to the basics of steel reinforcement corrosion and the subsequent formation of cracks in the concrete cover generated by the expansion of corrosion products. Models describing the corrosion and concrete deterioration processes are covered. Several formulae and models have been proposed for the calculation of the time to onset of cracking of the concrete cover caused by the reinforcement corrosion. Some analytical models are deduced from electrochemical and mechanical principles and some empirical expressions are obtained according to experimental data fitting. Various studies show considerable variations in the extent of corrosion required to initiate cracking and the influence of cover thickness and steel bar diameter. So far the models for crack initiation and propagation have been restricted to the stresses generated by the expansion of corrosion products. Models comprising the total complexity of the problem, especially generated by load induced stresses, have not been found. Further research should focus on developing models based on electrochemical, chemical, physical and mechanical parameters only, without introducing numerical coefficients to fit empirical data.
