Geotechnical Engineering Centre, University of Queensland
Globally, massive volumes of natural and manufactured (quarried) sand are extracted every year, mainly for use in construction. Natural and manufactured sand has become the second biggest resource mined and traded by volume on Earth, after freshwater. A lmost 50 billion tonnes of natural sand and gravel are extracted every year, equivalent to nearly 18 kilograms per person per day, greatly exceeding formation rates, damaging the environment, harming animal and aquatic species and adding to biodiversity loss. Indiscriminate natural sand mining could also promote coastal erosion, making coastal communities susceptible to natural disasters while bringing economic losses to the eco-tourism industry. Simultaneously, several countries face a looming risk of a shortage of natural sand to meet their domestic requirements, skyrocketing prices of natural sand, and even causing conflicts and regulatory challenges due to illegal sand mining in many parts of the world. A massive 1 million tonnes of waste glass are stockpiled every year in Australia, causing disposal challenges, adding pressure on landfills and bringing
economic losses due to its indefinite storage in warehouses in many councils, arising mainly from the limited end-uses of waste glass. Waste glass is non-biodegradable, and its landfilling might not be an ideal disposal choice as it could occupy valuable land space that might otherwise be used for high-productivity applications. Also, the expensive colour sorting of the mixed-coloured waste glass often makes it uneconomical for re-use.
Danish Kazmi, a PhD Candidate and researcher at the GEC, is researching the use of crushed waste glass obtained from 100% recycled glass as a total replacement for traditional construction sands, specifically for use in sand columns to reinforce ground of poor bearing capacity. The primary mineral present in waste glass and traditional construction sands is silica. Using crushed waste glass as a replacement for natural and quarried sand in geotechnical construction could offer a double sustainability benefit by conserving a depleting natural resource and
GEC rooftop instrumented slurry consolidation/desiccation/ cover columns 42 | Endeavour Magazine