Abstract
Mortars with and without damage by alkali-aggregate reaction were stored under atmosphere rich in CO2, and the change of the characteristics during the storage was measured for elucidating the effect of alkali-aggregate reaction on the carbonation of concrete. It was found that microcracks arising from the alkaline-aggregate reaction act as channels for the diffusion of CO2 and accelerate the carbonation of mortars. The resultant CaCO3 fills the cracks and pores, so that the characteristics of the mortars are improved at the expense of the alkalinity of the mortars. Neutralization of mortars was found to precede, seemingly, the carbonation under the atmosphere rich in CO2
