Every year, 92 million tons of clothes are disposed of into landfill; currently, very few are recycled. One method of destroying this waste is by burning it. However, this releases “various toxic gases, creating [serious] environmental concerns,” according to a team of researchers at RMIT University in Melbourne, led by Dr. Chamila Gunaserkara.
In Australia, we are the second largest per capita consumers of textiles worldwide, after the United States. On average, each person purchases 27kg annually, 23kg of which end up discarded immediately.
Modern society relies on concrete for our houses, transport and safety. However, this crucial material is prone to cracking. Not only is this a serious safety concern, but it is a multi-billion dollar headache. In Australia, it costs upwards of $8 billion every year just to maintain existing concrete structures.
“This is a textile fibre-reinforced concrete,” Gunasekara told Cosmos.
Traditionally, “when we place concrete, maybe an hour or two later the first cracking starts – the water evaporates from the concrete placement, then the concrete starts to shrink.” This “not only makes a building look bad but also risks its structural integrity and safety.”
While this problem can be minimised by the use of steel cabling, the steel itself is still very rigid and therefore not flexible enough to resist fracturing.
Contrastingly, textile fibres are “like a rubber band” and “very flexible” says Gunaserkara. In this new project, “Fibres are distributed almost evenly throughout the cement matrix. Then, when a crack is initiated, fibres will go around the crack [and] absorb the stress in the cement matrix.”
Initially, the team focused solely on discarded clothes. However, after success with this, they questioned whether “[They could] use this the same principle for other [wastes], like carpet waste?”
Now, the process is designed to be non fibre specific and incorporate many different fibre compositions indiscriminately. This reduces the energy and machinery required to sort and prepare fibres.
“Up to 70% of textile waste would be suitable for conversion into usable fibres,” according to Dr. Shadi Houshyar, a textile and material scientist at RMIT.
It is also able to incorporate “almost 100% non-recyclable” fabric, including firefighting uniforms, which are designed to be flame retardant and almost impossible to conventionally recycle.
The team is now working to upscale the technology and test long-term durability. They are partnering with local councils to trial larger slabs in communities. “[This] can be a concrete slab on the ground, or maybe up to a 50-100m footpaths,” ideated Gunaserkara.
“Imagine the potential if every landfill-bound carpet fibre could instead strengthen the foundations of our buildings,” said Houshyar, “It’s a win-win for sustainability and innovation.”
Gunaserkara’s research is an example of the type of solution we need as we advance towards a more sustainable future. It not only reduces waste but also tackles longstanding efficiency gaps.