Researchers have made stronger, more durable concrete using a surprising ingredient: scrap carpet fibers.
RMIT University in Australia has discovered this new way to turn waste carpet fibers into a key component for crack-resistant concrete.
Australia spends a hefty A$8 billion annually to fix cracked concrete structures. Meanwhile, the US spends a whopping US$76 billion annually on concrete repairs.
This highlights the need for innovative solutions to prevent and repair these cracks, which can weaken structures and compromise safety.
“Scrap carpet fibers can be used to increase concrete’s strength by 40% in tension and prevent early cracking, by reducing shrinkage substantially,” said Chamila Gunasekara, the lead researcher.
30% reduction in cracking
This innovative approach addresses a major issue in the construction industry: early-age cracking. By reducing shrinkage, the new concrete formulation enhances durability and extends the lifespan of structures.
Interestingly, the new technique significantly reduced early-age concrete cracking by up to 30%.
“Cracking in early-age concrete slabs is a long-standing challenge in construction projects that can cause premature corrosion, not only making a building look bad but also risking its structural integrity and safety,” Gunasekara added.
For now, the researchers have created laboratory concrete samples using discarded fabrics. These textile-reinforced concrete samples complied with Australian Standards for engineering and environmental criteria.
Discarded firefighting clothes can also be used
The researchers highlight the major environmental burden associated with the disposal of carpets and other textiles.
Carpets are often made from synthetic materials like nylon, polyester, and polypropylene. These materials contain various chemicals, including flame retardants, dyes, and adhesives. When burned, these chemicals decompose and release toxic gases into the atmosphere.
Moreover, the outdoor burning of carpet waste results in the contamination of soil and water with toxic ash and particulate matter.
“Australia is the second largest consumer of textiles per person in the world, after the US. The average Australian purchases 27kg of new clothing and textiles every year, and discards 23kg into landfill,” Gunasekara said.
Beyond carpets, the team is exploring the use of other textile waste, such as discarded clothing and firefighting gear, to enhance the performance of concrete further.
Shadi Houshyar, a textile and material scientist at RMIT, highlighted the challenge of recycling firefighting clothing. The very qualities that make these materials firefighting heroes, such as their flame resistance and durability, make them recycling villains.
“Up to 70% of textile waste would be suitable for conversion into usable fibers, presenting an opportunity in the materials supply chain,” said Houshyar in the press release.
Standard concrete production is energy-intensive and contributes to significant carbon emissions. However, this new method is sustainable.
It reduces waste and significantly improves the concrete’s properties. It’s a double win for the environment and construction.
Up next, the researchers aim to conduct field trials and computational modeling of this concrete mixed with carpet fibers. Field trials will enable the assessment of the concrete’s performance under actual construction conditions.
By partnering with industry and local governments, the researchers aim to accelerate the adoption of this sustainable solution.
The findings were published in the Construction and Building Materials journal.
