Mathematical Model on Progress of Carbonation of Concrete

Recently, some mathematical models for the prediction on progress of carbonation of concrete were reported. These models were taking account of CO2 diffusion and chemical reaction of Ca (OH) 2 and CO2. These models were based on the assumption that CO2 diffused in the carbonation zone and reacted with Ca (OH) 2 at the boundary face of carbonation zone and uncarbonation zone. In these models did not coexist. According to previous studies, however, it was know that Ca (OH) 2 and CaCO3 do coexist in carbonation progress zone. In this study, a mathematical model to predict the progress of carbonation of concrete has been established based on the reducing concentration of Ca (OH) 2 in the carbonation progress zone where Ca (OH) 2 reacts with CO2 and Ca (OH) 2 and CaCO3 coexist.