Environment

Recycled tires may help concrete take the heat

Recycled tires may help concre...
Along with using polymer fibers from tires to help release moisture from hot concrete, the scientists are also looking at using tire-derived steel fibers to help hold the material together
Along with using polymer fibers from tires to help release moisture from hot concrete, the scientists are also looking at using tire-derived steel fibers to help hold the material together
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Along with using polymer fibers from tires to help release moisture from hot concrete, the scientists are also looking at using tire-derived steel fibers to help hold the material together
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Along with using polymer fibers from tires to help release moisture from hot concrete, the scientists are also looking at using tire-derived steel fibers to help hold the material together

Although concrete doesn't burn, it can "spall" when subjected to extreme heat – this means that surface layers of the material explosively break off, potentially causing structures made from it to collapse. According to a new study, however, fibers obtained from discarded tires can help keep that from happening.

Already, some companies have been adding polypropylene fibers to concrete, to prevent spalling. The idea is that when the concrete is heated by fire, those fibers will melt, creating networks of tiny channels throughout the material. Any moisture present within the concrete can then escape through those channels – it would otherwise remain trapped, turn to steam, and force the material to break.

Typically, the fibers used for this purpose are composed of virgin polypropylene, which requires a considerable amount of energy and resources to produce. Scientists at Britain's University of Sheffield, though, have determined that fibers harvested from old tires are just as effective. More precisely, those fibers come from a textile reinforcement material that is commonly used in tires.

The researchers are now working with Sheffield-based construction firm Twincon, refining a cost-effective technique for separating the fibers from tire rubber, untangling them, and then distributing them evenly within a concrete mixture. They are also looking at various fiber-to-concrete ratios, and at using different types of concrete.

"Because the fibers are so small, they don't affect the strength or the stiffness of the concrete," says Dr. Shan-Shan Huang, lead author of a paper on the study. "Their only job is to melt when heat becomes intense. Concrete is a brittle material, so will break out relatively easily without having these fibers help reducing the pressure within the concrete."

The paper was recently published in the journal Fire Technology.

Researchers at Canada's University of British Columbia have been conducting similar research, making concrete more crack-resistant by adding polymer fibers taken from discarded tires.

Source: University of Sheffield via EurekAlert

3 comments
Nik
There's no shortage of tires for material. In fact, anything that can demolish the mountains of decomposing discarded tires, worldwide, must be good. However, what happens to all the remaining unused components of the tires?
Robert Schreib
Well, if the remaining unused components of the tires include steel belts like the puncture-proof radial tires have, perhaps they could be used, recycled or upcycled into $CHEAP$ bulletproof vests, which the general public's citizens could actually afford to buy. I hate to say this, but, the USA has turned into a nation where you, me, everyone, CANNOT GO ANYWHERE, without the risk of being shot. Perhaps some project like this, could lower our collective body count in the long run at least. and, perhaps the steel mail layering, in the exploded air bags from cars that crashed, could be recycled the same way. Also, if we have a lot of rubber particles left over from this mass-recycling of old tires, it could be feasible now to create various microwave machines, which could be used in a high pressure stamping machine, to compress and heat-weld these discarded rubber particles together, into new products or construction materials or some sort.
BrianK56
With all of the carpet fibers available they might be a good choice. I believe it is the same materials.