Landfill waste is a global concern that is creating wide-reaching environmental ramifications – but researchers from the University of Southern Queensland have new recycling options firmly in their sights to help shift the world towards a circular economy that reduces waste and keeps materials in use for longer.
Globally, 75% of tyres and glass, and 55% of plastics end up in landfill yet only around 20% of plastics and glass, and 10% of tyres, are actually recycled.
UniSQ’s Centre for Future Materials recently completed a review of the three materials that was published in the Resources, Conservation and Recycling journal to investigate their performance as construction materials, current applications in civil infrastructure and future opportunities.
Civil Composites theme leader Professor Allan Manalo said moving towards a circular economy where waste materials were minimised and kept in use for as long as possible was the way of the future.
“Making new materials from completely recycled materials has many possibilities,” Professor Manalo said.
“Material like crumb rubbers made from recycled tyres used as aggregates in concrete show improved dynamic properties, while glass sand has a minor impact on the mechanical properties when used to replace natural sands in concrete.
“However, only a small amount of these wastes is currently mixed with concrete, which may not be the most effective way of making use of them.
Professor Manalo said the review conducted by his team and colleagues at the Centre for Future Materials highlighted the fact that there was limited scientific evidence available on which type of waste was the best for a particular type of application.
“This is something that our Centre is working hard to address through a number of research projects that are developing ways to value add and convert waste into sustainable construction and building materials.
“We are focusing on novel and high-volume landfill waste-based material systems to effectively increase recycling rate of these waste materials,” he said.
“We have achieved significant results from our extensive research and development projects on novel and cost-effective polymer composite railway sleepers that utilise up to 25kgs of waste materials like recycled plastic, fly ash, recycled crumbed rubber and recycled glass.
“These are now being used to replace more than 100 million deteriorating timber sleepers in Australia, estimated to cost more than $1 billion.
“Increasing material efficiency, extending product life, improving recycling efficiency and helping to increase the use of recycled products and market demand for minimising volume of landfill waste is an exciting focus for the University of Southern Queensland.
“We are confident that ‘waste management’ will be replaced by ‘sustainable materials management’ in the future which will have a very positive impact worldwide.”
Find out more about research happening at the University of Southern Queensland’s Centre for Future Materials.
Civil Composites theme leader Professor Allan Manalo says moving towards a circular economy where waste materials were minimised and kept in use for as long as possible was the way of the future.