Bamboo - the steel of the future?

[TheMitchells]

https://reasonstobecheerful.world/bamboo-building-construction-hong-kong/?utm_source=Reasons+to+be+Cheerful&utm_campaign=35cae6aa4a-EMAIL_CAMPAIGN_2021_11_22_04_40_COPY_01&utm_medium=email&utm_term=0_89fb038efe-35cae6aa4a-389709485

Found this and thought some of you may like to read it.  

 

[SteamyTea]

Not sure how plentiful it really is. Takes a lot of land and water.

 

 

Microwaved bamboo could be used to build super-strong skyscrapers

TECHNOLOGY 24 April 2020

By Alice Klein

 

New Scientist Default Image

Bamboo can be made strong enough to build planes or cars by microwaving it

 

Aaron French/EyeEm/Alamy

 

Scientists have created an exceptionally strong, lightweight material out of microwaved bamboo that could be used to construct the next generation of skyscrapers, cars and aeroplanes.

 

At the moment, steel, concrete and bricks are the most commonly used construction materials, but they are non-renewable and their production contributes substantially to global greenhouse gas emissions.

 

Bamboo, in contrast, is a fast-growing, renewable material that is already used in houses and scaffolding in many Asian countries. However, it is not strong enough in its natural form to construct tall buildings.

 

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To make bamboo stronger, Liangbing Hu at the University of Maryland in the US and his colleagues treated it with chemicals to partially remove a substance called lignin, then microwaved it to remove water. This caused the bamboo to shrink by about a third of its size and its cellulose fibres to pack together in dense layers.

 

The tightly-packed cellulose layers were able to form strong chemical bonds called hydrogen bonds that enhanced the strength of the bamboo while still maintaining its lightness, says Hu.

 

Read more: High-tech wood could keep homes cool by reflecting the sun’s rays

The tensile strength of the microwaved bamboo – or the amount of stretch it could withstand without breaking – was 6 times that of steel when compared by weight. It could also withstand slightly more compression than concrete and bricks and did not degrade when left outdoors.

 

These properties make the material suitable for constructing skyscrapers that would be lightweight but stay stable by being strongly bolted to the ground, says Hu. It could also potentially be used to make lighter electric cars that could make up the weight with bigger batteries for travelling further, or lighter aeroplanes that require less fuel to propel them, he says.

 

Hu’s team and other research groups have also used wood to make super-strong, renewable building materials, but bamboo has the advantage of growing faster, meaning it can be produced on a larger scale, he says.

 

Hu and his colleagues are now planning several engineering projects to test the potential of their microwaved bamboo in real-life building contexts.

 

Journal reference: ACS Nano, DOI: 10.1021/acsnano.9b08747

 

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Bamboo road bridge can support 16-tonne trucks

 

TECHNOLOGY 19 December 2007

By Mason Inman

 

The novel bridge with horizontal beams made from a bamboo composite proved strong enough to support even heavy trucks

(Image: University of Southern California)

 

Bridges built from bamboo instead of steel could provide a cheaper, more environmentally sustainable engineering solution in China, a recent experiment suggests.

A novel type of bridge with horizontal beams made from a bamboo composite proved strong enough to support even heavy trucks in tests. The bamboo beams are cheaper and more environmentally friendly to make than steel or concrete, yet offer comparable structural strength.

Yan Xiao, who works at the University of Southern California, in Los Angeles, US, and at Hunan University in China, led the development of the bamboo beams used to make the bridge.

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Instead of using round, pole-like pieces of unprocessed bamboo, which have been used as building material for many thousands of years, he came up with a way of assembling timber-like beams from many smaller strips of bamboo.

Precise details on the process remain proprietary, but Xiao says the strips are cut from large stalks of bamboo, arranged in multiple layers, and bonded together with glue. The technique has never been used to build such large beams before, Xiao says.

Sustainable harvest

Last week workers finished assembling a 10-metre long bridge of Xiao’s design in the village of Leiyang in Hunan province, southern China.

 

Using prefabricated beams, it took a team of eight workers just a week to assemble and did not require heavy construction equipment. It proved strong enough to carry a 16-tonne truck and, and based on structural testing of the bridge, should be able to support even more weight, Xiao says.

Pound-for-pound, bamboo is stronger than steel when stretched and more robust than concrete when compressed. Also, stalks several meters tall mature in just a few years, rather than a few decades as with trees, so more can be harvested from the same amount of land.

Furthermore, since it is a grass it can be harvested like mowing a lawn – leaving the root system intact so that the plant can regrow.

Green solution

Bamboo beams could work for bridges up to 30-metres long, Xiao says, making them suitable for carrying pedestrians in cities or cars on highway overpasses.

“I think very highly of the work that professor Xiao is doing,” says architect Darrel DeBoer, who works with unusual building materials. “It’s quite worthwhile to find alternatives to the concrete that we are using way too much of.”

DeBoer notes that cement production releases a lot of the greenhouse gas carbon dioxide: 5-10% of global CO₂, according to different estimates. This is an unavoidable part of the chemical process used to make cement from calcium carbonate.

Bamboo, on the other hand, soaks up CO₂, as it grows. “From an environmental perspective, bamboo is a great choice,” DeBoer says.

Cars and Motoring – Learn more about the latest technologies in our comprehensive special report.