Graphene Makes Concrete Twice As Strong While Reducing Carbon Emissions (inhabitat.com) 90
Paige.Bennett writes: In a recent study, University of Exeter's Center for Graphene Science used nanoengineering technology to add graphene to concrete production. The resulting graphene concrete is two times stronger than traditional concrete and four times as water resistant, but with a much smaller carbon footprint compared to the conventional process of making concrete. According to the research, the addition of graphene cuts back on the amount of materials needed in concrete production by nearly 50 percent and reduces carbon emissions by 446 kg per ton.
Ha! (Score:1)
Re: Ha! (Score:1)
Wrong!
Re: (Score:1)
Continuous Graphene production (Score:2)
Scaling graphene production for real (Score:3, Insightful)
Re: (Score:2)
...unless they don't use it in *everything*.
Maybe they could only use it in important things, like bridges.
Or maybe they could have more than one machine making it. Multiple machines in parallel would make more.
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
Re:Ha! (Score:5, Informative)
Bold claim considering CVD is the only viable way produce graphene.
CVD is not the only way to make graphene [wikipedia.org].
Graphene is currently way too expensive for a bulk product like concrete, but if a big market is available more research will go into mass production techniques. More research should go into reinforcing concrete with other substances as well. I have seen concrete reinforced with peat moss, coconut fibers, and shredded bamboo. These increase tensile strength, and shock absorption, but reduce compressive strength.
Re: (Score:2)
Bold claim considering CVD is the only viable way produce graphene.
CVD is not the only way to make graphene [wikipedia.org].
Graphene is currently way too expensive for a bulk product like concrete, but if a big market is available more research will go into mass production techniques. More research should go into reinforcing concrete with other substances as well. I have seen concrete reinforced with peat moss, coconut fibers, and shredded bamboo. These increase tensile strength, and shock absorption, but reduce compressive strength.
Rebar; also, too, and either.
Re: Ha! (Score:4, Insightful)
From the article (I know, I know): ...The production of 1m3 of concrete requires ~ 360kg of cement (assuming 1:1.5:3 materials ratio, 0.45 w/c). Therefore the addition of 125g of graphene ($0.45 per gram [4]) can decrease the total volume of cement down to 148kg per 1m3. ...
OK, so now we know the actual ratio required for the stated benefit. One gram of graphene replaces about 1.7 kilograms of cement. [(360 - 148)kg / 125g]
At $0.45 per gram it is not yet cost competitive (here in the states anyway) but it is only about an order of magnitude off, which for an initial attempt in a new material is not that bad.
i have been a practicing structural engineer for well over thirty years. So we all understand, the bulk of concrete design is typically not controlled by the concrete design strength; because concrete failures are brittle (sudden) they are avoided. There are other admixtures/components currently in use that provide the other stated benefits. Consequently, cost will be, as usual, the determining factor in graphenes adoption.
-SET
Re: (Score:2)
You know, there are literally hundreds of highly effective commercialized concrete additives, many of which achieve as good results.
I also note their claim of carbon emission reductions seems to hinge on both finding a pile of graphene sitting pre-made and free next to their production line (they dont allow for the huge energy requirement of production), and in them counting that carbon itself as now sequestered (which it is, at massive energy and financial cost).
Basically this is a rather stupid academic e
Re: (Score:3)
I've heard many times that producing concrete is a huge generator of CO2.
It is. But graphene costs $100 per gram, while concrete costs $100 per tonne. So the price of graphene needs to decline a million-fold before it is in the price range of concrete. For now, using graphene in concrete is a fantasy.
If you want to spend a limited amount of money reducing atmospheric CO2, buying graphene to add to concrete would be one of the stupidest things you could do.
Re: (Score:3)
Your assumption is that they need equal quantities of graphene and concrete. I'd be pretty certain that is a false assumption.
Since this process halves the amount of concrete needed, the graphene needs to be less than $50 per . Not only that but the graphene improves the water resistance of the concrete which means that buildings made of it will last longer which is another cost saving.
Re: (Score:2)
Re: (Score:2)
The article is crap and makes no sense what so ever. Concrete is two, three, four, five times stronger than concrete and even more. Typical regular mix is 20MPa compressive strength but you can do 60 or even 80 dependent upon the aggregate you use, coarse and fine, curing time and additives as well as the quality of the cement itself, how fine or coarse. So either their super graphite concrete is only 20 Mpa or 120 MPa, quite the difference. The big problem with concrete is it's tensile strength which is cr
Re: (Score:2)
Concrete is two, three, four, five times stronger than concrete and even more.
What? What material is stronger than itself?
Half the carbon footprint? (Score:2)
2 articles (Score:5, Interesting)
"We do not yet know whether graphene flakes can become airborne and inhaled in a form that is dangerous during use."
Are carbon nanotubes the next asbestos? [biomedcentral.com]
"The difference with asbestos was that the hazards were not known or ignored; large-scale use meant large-scale production, resulting in emissions that weren't properly controlled, which in turn caused exposure at unsafe levels and then widespread disease. This should never have happened and should never again happen."
Re: (Score:1)
"The difference with asbestos was that the hazards were not known or ignored; large-scale use meant large-scale production, resulting in emissions that weren't properly controlled, which in turn caused exposure at unsafe levels and then widespread disease. This should never have happened and should never again happen."
This is so wrong and short-sighted it boggles the mind. A Trump tweet couldn't be more wrong. While your base assertions are correct in that we do not yet know if graphene can have unintended effects, the assumption that an asbestos/tobacco/oxycontin/BPA/micro-plastics etc situation won't happen again is completely incorrect. Never underestimate the ignorance and greed of people combined with the possibility of wealth and the unknown. The latter is the absolute fallback point - if you literally don't know,
Re: (Score:1)
Re: 2 articles (Score:1)
Twice as strong? (Score:5, Funny)
Of course, I'm not a structural engineer. But I did read a book called Structures; Why Things Don't Fall Down so I think I'm qualified.
Re:Twice as strong? (Score:5, Informative)
increase of up to 146% in the compressive strength, up to 79.5% in the flexural one, and a decrease in the maximum displacement due to compressive loading by 78% ... 88% increase in heat capacity ... decrease in water permeability by nearly 400% ... reduction by 50% of the required concrete material while still fulfilling the specifications for the loading of buildings.
Re: (Score:1)
How can it decrease permeability by more than 100%?
Would that mean it actively expels water at three times the rate concrete absorbs it normally?
Re: (Score:2)
Re: (Score:1)
Think of it the other way. The new material is only 25% as permeable as the original concrete.
Re: (Score:1)
Of course, I'm not a structural engineer. But I did read a book called Structures; Why Things Don't Fall Down so I think I'm qualified.
So you read a book on the subject. But did you stay at a Holiday Inn Express last night, smarty pants?
Re: (Score:2)
You obviously don't understand the problems with asbestos. And you'd have to show the (for me) new data that shows graphene as having damaging effects when inhaled greater than the standard "embeds in lungs" materials. Because the problem with asbestos and beryllium particles aren't that they just embed in lungs.
Re: (Score:2)
Will someone make graphene cereal already? I mean everything is better with graphene. Where are the Graphene Puffs? I know they'll stay crunchier in milk than regular cereal. They probably won't go stale as fast either.
I know it'll be better for the environment. Graphene Puffs won't need as much protective packaging to avoid being crushed, so less waste and weight to transport. Plus they'll be lighter per box than regular cereal.
I'm sure that they'll be the perfect weight loss food as well. One bowl of Graphene Puffs should take about 4000 years to digest.
As long as you don't use Aaamond Milk; since I understand the irrigation water in the primary harvest region is a costly environmental consideration.
how does this compare to pumice? (Score:4, Interesting)
I remember hearing long ago how adding pumice to concrete made it better able to resist water damage. Supposedly that was the reason that aqueducts and other Roman structures exposed to water survived for centuries. I don't suppose pumice has the CO2 benefits but it's also something just needs to be mined and not made.
Though I doubt either one is available in the quantities needed to be really useful. Also wasn't there some report on us running out of the sand needed for concrete at our current rate of use?
Re: (Score:2)
If you can figure out how to combine graphene and bitcoin, you'd be rich!
Re: (Score:1)
Roman Concrete (Score:4, Interesting)
They would be better off studying how to reproduce Roman Concrete. There are Mediterranean docks that are over a 1,000 years old that are in better condition than when they were new.
https://www.smithsonianmag.com... [smithsonianmag.com]
Re:Roman Concrete (Score:5, Informative)
As articles like that point out, they do know how.
It isn't used because it is more expensive. Simple.
This is even more expensive, and even better. So, even less useful.
Re: (Score:1)
Re: (Score:2)
Right, but that's only a reading comprehension issue.
They don't know exactly how the Roman's made it, they do know what it was made of, and we have modern techniques for mixing the materials and making the forms. You're mistaking not knowing the details of their technique for not knowing the details of the result.
Just like if you dig up an old shoe from 10k years ago, we don't know the details of their construction technique; what sort of needle or punch was used to make the holes, what sort of frame did th
Re: (Score:2)
The Romans came up with the idea of building stuff out of brick faced, marble veneered concrete rather than solid blocks of dressed marble. The result looked the same as the solid blocks of dressed marble the Greeks used, but cost only a fraction of the price. They then took the savings and plowed it into building on a monumental scale.
It's pretty clear: without their awesome concrete, Ancient Rome wouldn't be Rome. Each of its million inhabitants received over a cubic meter of water a day, supplied by co
So what does it do for hempcrete? (Score:1)
Almost there, with the graphenecrete (Score:3)
Re: (Score:1)
Does it have to be 3D-printable as well?
Real world version by Robert Murray Smith (Score:4, Informative)
If you think graphene is a unicorn, try one of Rob's experiments.
Mixed Units (Score:2)
446 kg/ton. Is that a metric ton, an Imperial ton, or US ton? If it is a metric ton, why not just stick to kg for 0.446 kg of carbon per kg of cement?
I guess I should be glad they didn't give the units as balloons of CO2 per playground or pencil leads per building.
Re: (Score:2)
Anything with graphene has to be measured in space elevators per cargo bay (Earth Federation regulation size, unlubricated).
How Much? (Score:4, Insightful)
What will it cost? If it costs 100 times as much per ton they might as well not waste their time. We hear about all these miracles but it seems they are decades, maybe a century, away from being practical. Well, maybe one day.
Re: (Score:1)
Even if it costs 100 times as much per ton with current production methods, learning what works and does not work is useful because production methods tend to improve - often tremendously - when scaled.
In this case, since we want to bind carbon anyway, this could be an excellent - and at the end of the day cost efficient - way to do so compared to doing something less productive with the carbon while manufacturing concrete in the oldfashioned way.
How will we know? From these people "wasting their time" lear
How much does it cost? (Score:5, Insightful)
How much does it cost? Because lots of things are stronger than concrete. Steel, for example is like 20 times stronger than concrete in compression and basically infinitely stronger in tension.
Re: (Score:3)
This. Right now we can use carbon fiber to enhance concrete supports, but it's only done as a remediation due to the expense.
From the report they found their optimal mix as 0.7g of carbon fiber per liter of finished concrete (~0.3 g/kg). So with some back of the envelope math, an average office building might use 21,400 m^3 concrete. If we cut the concrete used in half, that would still require 7.5 metric tons of graphene. So the question is how much will 7.5 tons of graphene cost you, and is that more or
Re: (Score:3)
Is it worth it?
I watched a documentary on building skyscrapers. The concept that stuck with me was that building one higher was not like stacking another floor on top. It was like jacking up the entire structure and sliding another floor underneath.
In Dunn, NC, this wouldn't make any sense, but consider downtown New York. Chicago. Tokyo. Hong Kong. Adding a floor could mean millions more in revenue. If you cut the weight of all the structure in half, it becomes much easier to slide another floor unde
Additional Properties (Score:3)
It doesn't work to make an entire heated concrete floor feel warm to walk on with bare feet, because that will make the room's air temperature too warm to be comfortable. So, I have looked for ways to make just the pathways where one commonly walks warmer than the rest of a concrete floor, and I ran across mentions of graphene.
Re: (Score:2)
What is the use case, why not floor coverings, or slippers?
Re: (Score:3)
Re: (Score:2)
Floors heated to be warm to the touch are often done when the point is to heat the room that way.
In other cases where the floor is basically a heat sink that makes the room colder (like a basement floor) you can warm it without overheating the room.
Re: (Score:2)
Twice the strength of what? (Score:2)
Interesting combo with this: Graphene from air. (Score:1)
https://www.nature.com/article... [nature.com]
Results
Controlled synthesis of graphene in ambient-air environment
Currently, graphene synthesis involves several key factors need to be improved: (i) lengthy high-temperature annealing processes to increase the grain size of the metal catalyst used to form graphene; (ii) utilization of purified and compressed gases to offer a homogenous and controlled delivery of carbon source materials; and (iii) the use of lengthy vacuum operation to avoid the presence of any detrimental r
Obligatory (Score:2)
Re: (Score:2)
The best thing about graphene-based products is that we'll be able to power them with cold-fusion.
Sounds good, but.. (Score:2)
Roman Concrete (Score:1)
I was reading about how they rediscovered the recipe to "Roman Concrete"... apparently a chemical reaction with volcanic ash and salt water and some other ingredients. That is what we should be comparing things to. That stuff can sit at the bottom of the sea for over 1000 years and not be turned into sand. This stands in direct opposition to the current crap we are producing. After 5 years at our new office building I was able to rip up a chunk of sidewalk with my bare hand and crumble it.
Crushed recycled glass (Score:1)
How does this compare with using crushed recycled glass?
https://youtu.be/QCVrC0cutr8?t... [youtu.be]
What DOESN'T Get Better With Graphene? (Score:2)
Vanilla pudding, I suppose.
Oh yeah, and oyster stew.