Researchers at Washington State University (WSU) have created a new, strong, permeable pavement to combat storm water run-off on roads using recycled carbon fibre.
The new hard standing surface allows water to drain freely through the pervious concrete to the ground underneath.
The team said the addition of recycled carbon fibre “greatly strengthened” the concrete while requiring only the minimal amount of energy and chemicals to transform it to a usable state.
Impermeable paving can be a cause of flooding, as water is held on surface and not allowed to seep through to the ground underneath.
The new material has already been used on some car parks and low traffic streets in several cities the team behind the innovation said. But it warned because of its porous nature it was not strong enough for major road use.
The carbon fibre added to the mix was scrap received from Boeing manufacturing facilities. Mechanical milling was then used to refine the composite pieces to the ideal sizes and shapes.
WSU assistant professor in the Department of Civil and Environmental Engineering Somayeh Nassiri said the added material greatly increased both the durability and strength of pervious concrete.
“In terms of bending strength, we got really good results — as high as traditional concrete, and it still drains really quickly,” said Nassiri.
Nassiri went on to say Carbon fibre composites had become increasingly popular in numerous industries because it was super light and strong. But while the market was growing by around 10% a year, the industries had not yet worked out how to easily recycle the waste which could be up to 30% of the material used in production.
WSU associate research professor Karl Englund added that inexpensive milling techniques had been used instead of heat or chemicals to create a reinforcing element from the waste carbon fibre composites. This he said made use of the original strength of the composites by keeping them in their cured composite form.
“You’re already taking waste — you can’t add a bunch of money to garbage and get a product,” said Englund. “The key is to minimize the energy and to keep costs down.”