Ceramics-Silikáty 51 (2) 74-81 (2007)

PERFORMANCE OF SULPHOALUMINATE-BELITE CEMENT WITH HIGH C₄A₃S CONTENT

I. Janotka, Ľ. Krajči, S. C. Mojumdar

Sulphoaluminate - belite (SAB) cements are an attractive class of low energy cements from the viewpoint of energy saving and less CO₂ releasing into the atmosphere during their production. Their hydraulic activity, however, does not match that of the Ordinary Portland cement (PC) and needs improvement before they can be used on their own. Performance of SAB cement with 50.3 wt. % of C₂S, 20.2 wt. % of C₄A₃S, 19.5 wt. % of C₄AF and 9.7 wt. % of CS has been compared with that of PC having 67.6 wt. % of C₃S, 5.1 wt. % of C₂S, 9.2 wt. % of C₃A, 10.6 wt. % of C₄AF and 5.9 wt. % of CS, and blast-furnace slag Portland cement (BFSPC) containing 30 wt. % of blast-furnace slag. Mortars with the above cements and siliceous sand with the weight ratio of 1 : 3 and water to cement ratio of 0.5 were manufactured and 40x40x160-mm prisms were stored at 20 °C for 90 days under 100% R.H. - wet air conditions. The physical-mechanical properties (strengths, dynamic modulus of elasticity), shrinkage reducing properties and passivation ability of SAB cement approach to those of BFSPC. With further improvement in the SAB cement quality through better understanding of their characteristics, a genuine competition between SAB cement and BFSPC can be expected in practice.

Keywords: Blended cement, Mortar, Hydration, Sulphoaluminate-belite cement.