Prediction of Carbonation Depth of Concrete With Fly Ash

Abstract

This paper reports the accelerated carbonation test results in order to investigate the effect of replacement ratio of fly ash, initial curing period in water, and air content on the carbonation phenomena in concrete. Using these test results, equations for the prediction of carbonation depth of concrete with and without fly ash are proposed, and these effects are also evaluated by these equations. Furthermore, the accelerated carbonation test results are compared with natural exposure test results for 15 years, and a method to predict the carbonation depth of concrete with and without fly ash exposed to natural indoor conditions is proposed. Concrete with fly ash is affected by initial curing period in water rather than concrete without fly ash from the viewpoint of depth of carbonation and compressive strength. The higher the fly ash content of concrete is, the deeper is the depth of carbonation. Depth of carbonation can be evaluated by compressive strength of concrete cured in water for 28 days, irrespective of the fly ash content of concrete. Carbonation depth of concrete with and without fly ash naturally exposed indoors can be predicted by the equation obtained by the accelerated carbonation tests.