Use of waste glass as sand in mortar: Part I – Fresh, mechanical and durability properties

In this study, mortar made with waste glass as fine aggregates was investigated for its suitability for construction use. A reference mortar mixture was proportioned according to ASTM C 109 and the fine aggregates were replaced by waste glass particles by 0%, 25%, 50%, 75% and 100%, by mass, to study its effect on the properties of mortar. For each mixture, four types of glass sand, namely, brown, green, clear and mixed color glass, were used. Test results indicated that use of waste glass particles as fine aggregates would reduce the flowability and density of mortar, but increase its air content. Except drying shrinkage, the mechanical properties were compromised due to micro-cracking in glass sand and weakened bond with the cement paste. However, durability was enhanced, especially in terms of the resistance to chloride ion penetration. Accelerated mortar bar tests to ASTM C 1260 indicated that green and brown glasses were non-reactive while clear glass was potentially deleterious, with regards to alkali–silica reaction.