Alkali-activated Portland blast-furnace slag cement: Mechanical properties and hydration

The aim of this article was to study the kinetic, the mechanical development and the microstructure of an alkali-activated blended Portland cement produced from the mixture of a granulated blast furnace slag and Portland cement in proportion 80% and 20% respectively. The hybrid cement reported compressive strength 4.5 and 10.8 times higher than the reference (100% Portland cement) when is activated with NaOH and waterglass (sodium silicate + NaOH) respectively. Similarly, the heat of hydration was reduced and the material presented a fairly dense and compact microstructure. The main products observed were gel C-S-H, C-A-S-H and hydrated gehlenite.