Properties of one-part fly ash/slag-based binders activated by thermally-treated waste glass/NaOH blends: A comparative study

Inclusion of a blend of soda-lime glass powder and sodium hydroxide as an alternative dry activator (DA) powder in fly ash/slag-based one-part alkali-activated materials (AAMs) was investigated. The reactivity of the DA was studied and the properties of DA-based AAMs were compared with both one-part and two-part AAMs activated by solid sodium silicate (NS) and sodium hydroxide/sodium silicate solution (NHNS), respectively. According to results, DA showed reasonable reactivity after heat treatment. DA-based AAMs showed the lowest flowability, but the longest setting time. The strength of NHNS-based AAMs is the highest, followed by DA- and NS-based AAMs. The main reaction product of all types of AAMs is calcium-sodium aluminosilicate hydrate (C-(N)-A-S-H)-type gel. The number of mesopores was greater for both one-part (DA and NS) AAMs than for two-part (NHNS) AAMs. According to cost and emission analyses, DA-based AAMs are cheaper and greener than commercial activator-based AAMs. This study provides a detailed experimental investigation of one-part AAMs activated by an alternative activator to replace the use of commercial alkali silicates.