3-D printing 'greener' buildings using local soil:
The construction industry is currently facing two major challenges: the demand for sustainable infrastructure and the need to repair deteriorating buildings, bridges and roads. While concrete is the material of choice for many construction projects, it has a large carbon footprint, resulting in high waste and energy expenditure. Today, researchers report progress toward a sustainable building material made from local soil, using a 3-D printer to create a load-bearing structure.
[...] The researchers began by collecting soil samples from a colleague's backyard and tailoring the material with a new environmentally friendly additive so that it would bind together and be easily extruded through the 3-D printer. Because soils vary greatly by location, their aim was to have a chemistry "toolkit" that could transform any type of soil into printable building material. From there Bajpayee built small-scale test structures, cubes measuring two inches on each side, to see how the material performed when extruded into stacked layers.
The next step was to ensure that the mixture is load bearing, meaning that it will stand up to the weight of the layers but also other materials used in construction such as rebar and insulation. To help with this, the researchers strengthened the clay mixture by "zippering" the microscopic layers on its surface to prevent it from absorbing water and expanding, which would compromise the printed structure. With this method, the researchers showed that the material could hold twice as much weight as the unmodified clay mixture.
Journal Reference:
Aayushi Bajpayee, Mehdi Farahbakhsh, Umme Zakira, et al. In situ Resource Utilization and Reconfiguration of Soils Into Construction Materials for the Additive Manufacturing of Buildings, frontiers in materials (2020) 7:52. DOI: 10.3389/fmats.2020.00052
The approach is thought to both lower the environmental footprint of construction on Earth and model how construction can be effected on the Moon or Mars.
(Score: 2) by looorg on Friday August 21 2020, @04:19PM (9 children)
While interesting I'm not sure a 3D printed "soil" house would pass building inspection and standards here. I'm not saying that they never will but the code if fairly strict and you just can't put up any old shack if you expect humans to live in it. Also how is the longevity of the structure as far as maintenance and so goes?
(Score: 4, Informative) by c0lo on Friday August 21 2020, @04:48PM (3 children)
This [wikipedia.org] is what [atlasobscura.com] one (or many) [iranparadise.com] can [wikipedia.org] build [rammedearthworks.com] from mud [wikipedia.org]
Protect it from water and you'll be fine for centuries.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by looorg on Friday August 21 2020, @07:23PM (1 child)
Easier said then done if you are at the top of the world and at least half the year has snow and rain. At least there is plenty of wood and stone.
(Score: 2) by c0lo on Friday August 21 2020, @07:34PM
For now. Until the AGW takes over, that is (very large grin)
Did I suggested you to build one underwater?
Actually it is easy to do it, just use just a tad wider roofs and paint the walls in oil paint.
My grandparents' house was build from the mud bricks on top of a thin concrete foundation. It was better thermally insulated than all the apartments I lived in until now.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by Phoenix666 on Saturday August 22 2020, @12:43AM
Rammed earth was used successfully in China for thousands of years. Done right, it winds up with the strength and consistency of concrete. I did a quick search and saw this paper [wvu.edu], but with a little more time much more could be found.
Washington DC delenda est.
(Score: 4, Interesting) by DannyB on Friday August 21 2020, @04:51PM (1 child)
Building codes can be changed.
Those 99% people [wikimedia.org] are going to have to adapt to life in cheaper buildings.
Because maintenance is expensive, the buildings will be maintenance free. Accomplished by the stroke or a pen. Or a tweet.
To transfer files: right-click on file, pick Copy. Unplug mouse, plug mouse into other computer. Right-click, paste.
(Score: 2) by shortscreen on Friday August 21 2020, @08:48PM
Looks like the 1% screwed up. They let the 9% have most of the fresh water.
(Score: 2) by Thexalon on Friday August 21 2020, @11:29PM (1 child)
I have a buddy who builds mud buildings for a living, and while there are efforts to make that sort of construction up to code, right now most of the buildings he does in the US at least have to be agricultural buildings on paper if not in fact, because buildings that are considered agricultural in purpose have basically no building standards at all.
His stuff's still standing though, and it's incredibly easy to repair if it does get damaged. I've been in a few of them, and they're reasonably comfortable and fairly well-insulated.
The only thing that stops a bad guy with a compiler is a good guy with a compiler.
(Score: 2) by Phoenix666 on Saturday August 22 2020, @12:44AM
Rammed earth buildings are quite attractive, too.
Washington DC delenda est.
(Score: 2) by ChrisMaple on Saturday August 22 2020, @01:55AM
I've read that Frank Lloyd Wright's insistence on using local materials has caused some of his buildings to degrade prematurely. Impurities in local sand used for concrete, if I recall correctly.
(Score: 4, Informative) by Runaway1956 on Friday August 21 2020, @05:43PM (3 children)
People around the world have been making adobe, from time immemorial. Adobe isn't precisely "soil". Garden soil, or yard soil, or top soil, all contain a lot of biological material. Decomposing vegetation, for the most part, is important to healthy soil.
Adobe doesn't use much if any "soil". You've got to dig a little deeper to find the clays and sandy deposits that are useful for adobe.
If these people are using "soil", you can expect their products to start decomposing in pretty short order. The less organic material used in the building, the longer you might expect the structures to stand.
That alone is enough to tell you something. Sand, stone, and clay don't expand when wet. Clay gets soft, of course, but it doesn't expand. Organic materials do expand and contract, a lot, depending on the amount of moisture absorbed into it.
(Score: 3, Informative) by slinches on Friday August 21 2020, @06:30PM
Yeah, agree. Soil differences will make any approach they use limited. The only way to "3D print" a house using the massive slabs of caliche where I live would be to blast or collect enough loose chunks from the surrounding area to stack the pieces into a house shape. But the Puebloans probably hold the patents on that technology.
(Score: 1, Informative) by Anonymous Coward on Friday August 21 2020, @07:23PM
On the contrary. Clay expanding and shrinking with moisture is why foundations shift, move and crack in regions with clay. It has nothing to do with getting "soft".
https://en.wikipedia.org/wiki/Expansive_clay [wikipedia.org]
(Score: 2) by c0lo on Saturday August 22 2020, @12:56AM
Heck, no. The reason you need to use subsoil and not the fertile soil on top is because the later becomes friable when it dries - the soil particles don't stick well together.
Otherwise, cobb [wikipedia.org] has quite a lot of organic matter in the form of the straws - it helps keeping the clay together and preventing cracks (the straws, husks or any natural fiber that was added wicks the moisture inside the brick and ensure a more even drying).
Sand and stone, no.
Clay expands/contracts quite a lot with the variation of water content. Even very homogeneous pottery clay will crack when it dries if it's thick - like a mud brick.
Or if you stick one to the other pieces with different water content [handbuildersmonthly.com]
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by MostCynical on Saturday August 22 2020, @01:42AM
So now "3-D printing" means "made by a machine"?
Likely nore investment money with the buzz word.
Mud brick machines have been around for quite a while..
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