Statistical analysis and corrosion assessment of Nigeria steel rebars: Case study south-west, nigeria

Abstract

Corrosion assessment of rebars is very essential to predict the behaviour of reinforced concrete structures in different host environmental conditions. It also highlights the limitations of the local rebars. From the analysis, the severity of aqueous solutions on rebars was in the order H2SO4 > HCl > Na2SO4 > H2O for both imported and local bars, whereas the ratio of the severity of local to imported steel rebars in water, Na2SO4, H2SO4 and HCl were 1.59, 1.26, 1.79 and 1.20 respectively. All the steel bars experienced deterioration due to mass loss, characterized by colour change in all the solutions except NaOH solution where no visible reaction took place as H+ in the aqueous solution could not react with Na+ which is higher in the electrochemical series. Also, there is a smaller degree of uncertainty in the imported reinforcing bars size with COV in the range of 0.06 to 0.20 and the local reinforcing bars in the range of 0.25 to 0.75 for the same diameter size range. To end with, the findings would address permissible nominal cover for different host environment to prevent deterioration of steel reinforcement under chemical attack and in water.