To limit environmental impact related to the cement production process (CO2 release into the atmosphere and energy consumption), the current trend is to decrease the clinker content in cement through the use of mineral admixtures. For precast applications, an alternative solution is to use ternary binders such as cement/blast furnace slag/flash metakaolin. In this study, different proportions of slag and flash metakaolin are considered in order to investigate the mechanical (flexural and compressive strength) and durability (porosity, water absorption and permeability) characteristics of steam-cured mortars. The main properties of such binders should have high reactivity at an early age (1 day), optimal performance at 28 days, and enhanced longterm durability. The results show that ternary binder mortars have similar or ever better properties than the control mortar, which uses only cement. Moreover, mortars with binders with 25 percent flash metakaolin show better performance than the control mortar, particularly in terms of mechanical properties. From an environmental standpoint, saving up to 40 percent of clinker (with the ternary binder) is a promising approach that reduces energy consumption (-23 percent) and the amount of CO2 released into the atmosphere (-34 percent). (A) For the covering abstract of this conference see ITRD number E220308.
Samenvatting