The influence of heat and steam curing on the properties of one-part fly ash/slag alkali activated materials: Preliminary results

Abstract

This paper presents the preliminary results of an experimental research on the influence of heat and steam curing on the performances of one-part alkali-activated mortars based on low calcium fly ash (FA) and ground granulated blast furnace slag (GGBFS) with different GGBFS/FA ratios. The mortars were manufactured at equal water to precursor ratio and were activated by sodium silicate, potassium hydroxide and sodium carbonate in powder form. In general, by growing the GGBFS/FA ratio, the workability of fresh mortars decreases and the elasto-mechanical performance increases, independently of curing conditions. The heat and/or steam curing temperatures equal to 40°C or 60°C promote the development of higher early compressive strength respect to standard curing conditions (20°C), especially at high GGBFS/FA ratios, while no advantages were detected at longer ages.