Model of Concrete Carbonation as Limited Process – Experimental Investigations of Fluidal Ash Concrete

Abstract

The aim of the paper is to develop a theoretical model predicting carbonation depth of concrete made with fluidal ash replacement of cement. Experimentally determined model describes the depth of carbonation depending on time of exposition, w/s ratio and early-age curing conditions. A new mathematical formulation of carbonation depth as a hyperbolic function of time assumes that carbonation process is limitable in depth due to process of fulfilling concrete pores with carbonation products. The depth of carbonation in concretes made with portland cement and various quantities of fluidal ash (30%, 15%, 0% of cement mass replacement) was measured in environment with high CO2 concentration (1%). The test results are shown and used to derive equations for prediction of carbonation depth in such concretes.