Investigations on the durability of alkali-activated recycled glass

Abstract

This work undertakes research on alkali-activated glass cullet (AAGC), with glass being recycled from various sources. Three types of glass are studied and compared: flat glass, hollow glass, and windshield glass. The study conducted yields the main formulation parameters affecting the behavior of AAGC, namely the concentration of activation solution KOH (1, 2, 3, 5, 7 and 10 mol/l) and the curing duration (1, 2, 4, 7 and 14 days) at 60 °C. These parameters are evaluated in terms of both compressive strength and flexural strength. Different durability parameters are also examined in this work, i.e.: porosity accessible to water, capillary absorption, chloride ion diffusion, sulfate attack, acid attack, and the alkali-silica reaction. Results show that for all three recycled glass types, optimal synthesis occurs under the condition with 3 mol/l KOH and 7 days of curing at 60 °C. Durability tests reveal that AAGC synthesized from these three recycled glasses exhibit an acceptable resistance to acid solution, sulfate attack and alkali-silica reaction despite their high permeability compared with ordinary Portland cement (OPC).