Carbonate minerals in hydrated portland cement

Abstract

ALTHOUGH the physical effects of the carbonation of hydrated cements and mortars have been studied1-3, the way in which the carbon dioxide is held has not yet been clearly established. Most workers have assumed that it exists in the form of calcite ; but in work at this Division3,4 and elsewhere5 the quantity of calcite detected by X-ray diffraction and differential thermal methods is always much less than the amount of carbon dioxide recoverable from the samples. We have investigated this problem in some detail using samples of mortar and carbonated calcium silicate hydrate. © 1959 Nature Publishing Group.