Rebar corrosion of fly-ASH mixed concrete according to the placing environment

Abstract

In this study, RC mock-up wall specimens with fly ash were manufactured in normal and hot environments, and the effect of the quality of concrete surfaces on carbonation and corrosion of rebars was compared and reviewed. As a result, the density of the surface of the wall specimen placed in a hot environment is lower than that of the normal environment, so the rate of carbonation is accelerated. That tendency accelerates as the replacement rate of fly ash increases, but the depth of carbonation in the normal environment is similar to that of NPC up to 20% of the replacement rate of fly ash, and the half-cell potential value and polarization resistance value of rebars were the same or higher. However, if the addition rate of fly ash is excessive, the depth of carbonation of concrete became very large regardless of the construction environment, so the corrosion rate of rebar also increased rapidly.