Textile waste is a large problem, and when items have come to the end of their lives, it can be hard to recycle them, as individual fabrics require different processes to be correctly recycled. A recent project at RMIT University in Melbourne is turning textile waste into concrete sustainability. Engineers have been experimenting with incorporating fibres from old clothes and carpets into the concrete mixes, offering a solution to textile waste.

Claire Smith and Olivia Back, writers for Clayton Utz, state that “Australia is the second highest consumer of textiles per person in the world, behind only the United States of America.” Additionally, they explain the scope of the problem: “Each year, we discard around 23 kilograms of it to landfill. In total, approximately 800,000 tonnes of textiles are sent to Australian landfills each year.”

However, recently a research led by Dr. Chamila Gunasekara, an expert in construction materials and structural engineering at RMIT University, has found that old textile fibres can be used to create a new type of concrete, reports Ellen Phidian, a science journalist for COSMOS magazine. This has been done by cutting the textiles up into little 12mm lengths, and then being made into a concrete mix. This innovation also helps builders have more durable concrete. “When we place the concrete, maybe an hour or two later the first cracking starts – the water evaporates from the concrete placement, then the concrete starts to shrink,” explains Gunasekara. Steel fibres can reduce some of this cracking, but these fibres can still be very rigid. Textile fibres, on the other hand, are very flexible. “Fibres are distributed almost evenly throughout the cement matrix. Then, when a crack is initiated, fibres will go around the crack, absorbing the stress in the cement matrix.” By absorbing pressures from the drying concrete, these textile fibres can stop cracks from getting bigger, resulting in the concrete having 30% fewer cracks, than on average.

The researchers soon realised that other waste textiles, like old carpets, could also be used to create concrete. “We asked ourselves, why not apply this same principle to carpet waste?” says Gunasekara. After reaching out to industries that generate large amounts of carpet waste, the team found the process worked just as well for carpets. By avoiding the need to sort different fabrics, the approach was made more cost- and energy- effective.This led the team to test a variety of frequently used fibres such as nylon and polyester. “Up to 70% of textile waste would be suitable for conversion into usable fibres, presenting an opportunity in the materials supply chain,” says Dr. Shadi Houshyar, a textile and material scientist at RMIT.

Gunasekara’s team has got almost 100% non-recyclable fabrics to work as well. These fabrics are typically used in military and firefighting uniforms, so they are made to be unbreakable so that the wearer can survive extreme environments. They are almost impossible to repurpose when they have neared the end of their lives, except in concrete, making the project a huge step forward.

This breakthrough offers a more sustainable solution for the growing problem of textile waste while also having the potential to improve the durability and environmental impact of construction materials. The next time you might feel overwhelmed about fast fashion, or textile waste, remember that there are initiatives being taken to help these problems. Although it isn’t perfect, there is action starting to be taken.