Corrosion of Reinforcing Bars in Carbonated Concrete

Abstract

In all published studies of cement carbonation there has been general agreement that it must be considered as a cause of generalised corrosion in reinforcements, but quantitative data have been provided in very few cases. In the present work the intensity of attack has been modified by means of the accelerated carbonation of mortar specimens without additives, with $2\%~~CaCl^{2}$, and with $3\%~~NaNO^{2}$ It has been shown that a critical level of atmospheric moisture must also be present for considerable attack to occur. The measurement of polarisation resistance (Rp) has been used to evaluate the intensity of corrosion of the reinforcements. This method has already been usefully applied by the authors to investigations of corrosion of steel bars in hardened concrete specimens.