Alkali activation of Australian slag cements

Investigation of alkali activation of Australian slag (AAS) was carried out using sodium silicate, sodium hydroxide, sodium carbonate, sodium phosphate, and combinations of these activators. Compressive strengths in the range from 20 to 40 MPa were achieved for the pastes. The most effective activator was liquid sodium silicate. With this activator, the effect of curing at 60 degrees C, modulus (M-s) of sodium silicate solution and concentration of alkalis on the compressive strength and setting times have been studied. On the basis of this investigation, a sodium silicate solution with a low Na content and M-s = 0.75 is recommended for formulation of AAS concrete. (C) 1999 Elsevier Science Ltd. All rights reserved.