Evaluation of powdered glass cullet as a means of controlling harmful alkali–silica reaction

Abstract

It has been proposed that glass derived from container glass recovery can act to control harmful alkali–silica reaction in concrete when included in powdered form. However, the high sodium content of the material raises concerns about whether the release of this element could ultimately exacerbate the reaction. This paper reports on a study carried out on concrete mixes containing aggregate combinations known to undergo harmful alkali–silica reaction in combination with powdered glass, to establish its efficacy at controlling alkali–silica reaction. Glass suppressed expansion for a finite period of time, before expansion reached levels similar to or greater than the controls. It is therefore concluded that the use of powdered container glass is not suitable for controlling alkali–silica reaction. However, it is proposed that the sodium contribution from container glass is, in many cases, irrelevant, since the alkali contributions from the reactive aggregate combinations themselves appear to outweigh those from the glass.