Abstract :
Alkali Activated Binders are eco friendly produced by activating industrial waste products such as ground granulated blast furnace slag (GGBFS), Fly Ash (FA) etc. using alkaline solutions. The present research aims to investigate the effect of the alkaline activators on the strength characteristics of air-cured alkali activated concrete mixes using indigenous GGBFS-FA. The research highlights the effect of the sodium oxide dosages (Na2O, in the range of 4 to 6%) and the activator modulus (Ms) (i.e. the SiO2/Na2O ratio, in the range of 0.75 to 1.75) of the alkaline solutions, on the workability and strength characteristics of alkali activated GGBFS-FA concrete mixes for different ratios of GGBFS: FA (i.e.100:0, 75:25, 50:50 and 75:25). Further the flexural and split tensile strength were evaluated for optimal mixes for each dosage of Na2O. It was observed that the optimal Ms was 1.25 for GGBFS: FA ratios of 100:0, 75:25, 50:50 and 1.5 for GGBFS: FA ratio of 25:75.
Keyword :
GGBFS-FlyAsh, Activator Modulus, Sodium Oxide Dosage, Strength Characteristics