Study on the hydration of Ba-bearing calcium sulphoaluminate in the presence of gypsum

A new series of Ba-bearing calcium sulphoaluminate minerals are synthesized by a different equivalent of Ba2+, replacing Ca2+ in the C4A3S̄. By means of XRD, IR, SEM, etc, we studied the hydration of minerals in the presence of a certain amount of gypsum. The hydrates are AFt, BaSO4, and Al(OH)3 gel. This paper gives the reason for early strength and rapid hardening of Ba-bearing calcium sulphoaluminate cement.