A thermodynamic phase formation analysis at hardening of carbonate-containing cements

Using the Gibbs potential minimization method, a phase formation mechanism was studied during hydration of the 3CaO·Al2O3 — CaSO4 · 2H2O — СаСО3 system. It has been established that when the system contains up to 3–4 mass.% of СаСО3, it acts as an active component, forming calcium hydrocarboaluminates of various composition. With further increase in the СаСО3 content it starts acting as an inert additive as well. Introduction of СаСО3 into the system results in stabilization of ettringite, 3CaO·Al2O3·3CaSO4·32H2O within a hardened cement.

Author: S.P. Sivkov

Section: Science and production

Keywords: calcareous spar, Gibbs potential