Evaluations of frost and scaling resistance of fly ash concrete in terms of changes in water absorption and pore structure under the accelerated carbonation conditions

Abstract

In this study, the frost and scaling resistance of concrete with various fly ash (FA) replacement ratios exposure to air and accelerated carbonation conditions were investigated. The changes in water absorption were measured by RILEM / CIF test and in pore structure were measured by the Archimedes method and the mercury intrusion porosimetry method due to carbonation. Results show that the influence of FA and carbonation on the frost and scaling resistance of concrete can be ignored due to air bubbles by air entraining (AE) admixture in case of AE FA concrete. For Non-AE FA concrete, carbonation of FA concrete does not change the gel porosity/capillary porosity ratio, which is the reason for the frost resistance is not influenced by carbonation of FA concrete. Additionally, it is noteworthy to note that the scaling resistance is strongly connected to the pore volume above 75 nm, and that when exposed to carbonation, the scaling resistance tends to rise as a result of the increase in pore volume above 75 nm that occurs as a result of carbonation. Because of the addition of FA and carbonation, the frost and scaling resistance are far more reliant on the changes in pore structure than they are on the water absorption.