Non Portland cements and derived materials

The present paper deals with an overall interpretation of information regarding the behaviour of binders free of Portland cement, containing slag with or without fly ash, activated by sodium and calcium compounds. The information was obtained from experiments regarding the chemically bound water and mechanical strength determination, together with pH measurement, thermal analysis and X-ray diffraction (XRD). The results emphasize the possibility of obtaining alkali-activated binders incorporating slag and with or without fly ash and which have mechanical properties equivalent to normal Portland cement. The binder systems, especially those adequately activated and showing enhanced performance, can incorporate up to 40% fly ash without any major influence upon binder quality. Quantitative correlations between chemically bound water and mechanical strength of the hardened binder and the decisive factors of influence (e.g. composition and finesses of binders) are reported. (c) 2004 Elsevier Ltd. All rights reserved.