Sustainable utilization of crushed waste glass as sand replacement for production of eco-friendly interlocking paving stones

Abstract
In an attempt to ensure sustainability of construction materials, efforts were being made to reuse some non-biodegradable waste materials as substitute materials in mortar production. Sand is a major constituents in the production of mortar, however, using waste materials such as glass as partial or complete substitute for sand in mortar production will ensure the reduction on the needs to dredge for it, thereby preserving the very valuable natural sand resources within the environment. Furthermore, the use of crushed waste glass as a replacement for sand in the production paving stones will ensure that the paving stones are eco-friendly thereby eliminating the challenges of discriminate dumping of glass wastes in landfill. This research investigates the utilization of crushed waste glass as partial and complete replacement for natural sand in cement mortar for the production of interlocking paving stones (IPS). The waste glass was varied at various percentage proportions by weight to replace the fine aggregate in the cement mortar mixes. Laboratory tests which includes chemical composition, particle size distribution, specific gravity, and compressive strength were carried out on the crushed glass materials, sand and paving stone samples respectively. The obtained results show that the both the load and non-load bearing interlocking paving stones containing 20% crushed waste glass exhibited better performance in strength development than the control and other paving stone mixes containing various content of waste glass materials. This study demonstrates clearly that waste glass can be adopted to produce eco-friendly interlocking paving stones, and this will help both in the sustainable management of glass wastes and greening of the environment.