Activation of blended cements containing fly ash

This study has investigated the activation of reactivity of fly ash in diff erent blended cements such as lime-fly ash, lime-fly ash-stag and Portland fly ash cements. Experimental results have indicated that the addition of N a2SO4 can significantly increase the strength of all these blended cements. The activation effect happens mainly during the first 3 to 7 days. The gri nding of fly ash also increases its activity, but is not as effective as th e addition of Na2SO4. On the other hand, the combination of grinding and th e addition of Na2SO4 shows a much higher strength than a single activation method. Finally, this paper also discusses the feasibility of the addition of Na2SO4 in different cement and concrete products production processes. ( C) 2001 Elsevier Science Ltd. All rights reserved.