Alteration in molecular structure of alkali activated slag with various water to binder ratios under accelerated carbonation.

Carbonation of alkali activated materials is one of the main deteriorations affecting their durability. However, current understanding of the structural alteration of these materials exposed to an environment inducing carbonation at the nano/micro scale remains limited. This study examined the evolution of phase assemblages of alkali activated slag mortars subjected to accelerated carbonation (1% CO, 60% relative humidity, up to 28 day carbonation) using XRD, FTIR and Si, Al, and Na MAS NMR.

Chemical and Microstructural Properties of Designed Cohesive M-S-H Pastes.

Concretes can be exposed to a magnesium attack in several environments leading to the formation of magnesium silicate hydrates (M-S-H) and brucite (MH). The formation of M-S-H is likely to alter the properties of the cement matrix because it is linked to the decalcification of C-S-H. However, relatively few data on M-S-H exist in the literature.