Monday , August 15 2022

Fires of old tires can improve concrete fire resistant


recycling;; CC0

Pile old tires, symbolic picture

A new way of protecting concrete from fire damage using recycled materials from old tires has been proven successfully by researchers at Sheffield University.

The team used fibers removed from textile reinforcement that were typically included in tires to guarantee their performance. The addition of these fibers has been shown to the concrete mix to reduce the tendency of the concrete to prevent – where concrete surface layers break off – is explosive under the intense heat of fire.

Hand-made polypropylene (PP) fibers (PP) have been used to protect concrete structures from damage or collapse if a fire expires as a well-known technique. Many modern structures, including large-scale engineering projects such as Crossrail, have used a concrete that includes PP fibers for fire protection.

Sheffield's study is the first to show that these fibers do not have to be made of raw materials, but can be recovered from tires used.

"We have shown that these recycling fibers are equivalent to maternal PP fibers that require a lot of energy and resources to produce," explained lead conductor Dr Shan-Shan Huang, in The Department of Civil and Structural Engineering at the University of Sheffield.

"The use of waste materials in this way is less expensive, and better for the planet."

Fibers dissolve under the intense heat of fire, leaving networks of small channels. This means that moisture that is captured within the concrete can escape, rather than be caught, which causes the concrete to break out explosively.

"Because the fibers are so small, they do not affect the strength or strength of the concrete," said Dr Huang.

"Melting is only their work when heat becomes intense. Concrete is a busy material, so it will break relatively easily without having these fibers to help reduce the pressure within the concrete. "

Protecting the concrete from blocking fire means that reinforcing steel that runs through the concrete is also protected. When the steel reinforcements are exposed to extreme heat, they weaken very quickly, causing a structure to be much more likely to fall. Liverpool's Waterfront Car Park had suffered this type of fire damage in 2017, resulting in the ultimate demolition of the entire structure.

Working with Twincon, a Sheffield-based company that is developing innovative solutions for the construction industry, researchers have also developed technologies for the recovery of tires and tires and used.

This meant separating the fibers of the rubber tires, breathing the fibers to strands, and distributed equally to the concrete mix.

The team intends to continue to test the material with the different ratios of the fibers to concrete, and also use different types of concrete. They also intend to find out more about how the materials respond to heat at microstructur level. By scanning the concrete when it is heated, they will be able to see in more detail the structural changes that occur inside the material.

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