The use of waste glass as an activator in alkali-activated slag mortars

Alkali-activated mixtures are advantageous materials, being more sustainable and environmentally friendly as they do not contain cement. In this study, ground granulated blast-furnace slag was activated with sodium hydroxide solution and liquid sodium silicate. The use of ground waste glass as a source of silicate instead of sodium silicate was investigated. For this purpose, mortar specimens with sodium hydroxide content in different molarities were produced by replacing sodium silicate with ground waste glass. The mechanical and durability properties of the mixtures were examined under three different curing conditions: moist curing, air curing and air curing after 24 h at 60°C. The compressive and flexural strengths of the specimens were determined at the ages of 3, 7, 28 and 90 days. Capillary suction, water absorption, rapid chloride penetration, electrical resistivity, freeze–thaw and sulfate resistance tests were also performed. In consequence, it was found that waste glass can be used as an alternative silicate source in alkali-activated mortars.