Cement Corrosion: Calcium Silicate Hydrates

This is a simulation of the changing phases within a cylinder of cement paste (4 mm radius) that is attacked by carbonic acid, as in the experiments performed by Andrew Duguid. In this animation, phases in the CaO-SiO2-H2O system in the cement are shown. A well-known mineralogical zoning (sharp reaction/dissolution front) appears: first the calcium hydroxide (C-H) dissolves then the C-S-H, represented as tobermorite (Tob) and jennite (Jen), dissolves leaving a high concentration of calcite (Cal) near the boundary. Finally even the calcite dissolves, and only a soft silica gel (Sil) remains.

Cement Corrosion:

Calcium Silicate Hydrates

© Princeton University 2012