Cement Produces More Pollution Than All the Trucks in the World (bloomberg.com) 250
An anonymous reader shares a report: The most astonishing thing about cement is how much air pollution it produces. Manufacturing the stone-like building material is responsible for 7% of global carbon dioxide emissions, more than what comes from all the trucks in the world. And with that in mind, it's surprising that leading cement makers from LafargeHolcim in Switzerland to Votorantim Cimentos in Brazil are finding customers slow to embrace a greener alternative. Their story highlights the difficulties of taking greenhouse gases out of buildings, roads and bridges. After wresting deep cuts from the energy industry, policymakers looking to extend the fight against global warming are increasingly focusing on construction materials and practices as a place to make further reductions. The companies are working on solutions, but buyers are reluctant to pay more.
While architects and developers concentrate on the energy used by their buildings, it's actually the materials supporting the structure that embody the biggest share of its lifetime carbon footprint. Cement's contribution to emissions is especially immense because of the chemical process required to make it. About two-thirds of the polluting gases that come from cement production stem from burning limestone. Kilns are heated to more than 1,400 degrees Celsius (2,600 Fahrenheit), about four times hotter than a home oven set to the self-clean cycle. Inside the kiln, carbon trapped in the limestone combines with oxygen and is released as CO2, the most abundant greenhouse gas.
While architects and developers concentrate on the energy used by their buildings, it's actually the materials supporting the structure that embody the biggest share of its lifetime carbon footprint. Cement's contribution to emissions is especially immense because of the chemical process required to make it. About two-thirds of the polluting gases that come from cement production stem from burning limestone. Kilns are heated to more than 1,400 degrees Celsius (2,600 Fahrenheit), about four times hotter than a home oven set to the self-clean cycle. Inside the kiln, carbon trapped in the limestone combines with oxygen and is released as CO2, the most abundant greenhouse gas.
Hmm... (Score:5, Funny)
Cement Produces More Pollution Than All the Trucks in the World
Does this include all the Cement Trucks?
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Yes, truck built out of cement are a contributing factor.
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Trucks built of cement sounds like something North Korea would come up with due to lack of materials
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https://en.wikipedia.org/wiki/... [wikipedia.org]
Wrong link? (Score:4, Interesting)
Also, any numbers to back up this claim that a buildings cement releases more CO2 than the entire lifetime of heating, cooling, and lighting it?
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I would guess they must be talking about very efficient buildings relying on very clean fuel sources because the numbers definitely don't work for my area.
In 2017 my state generated about 2,631.3 kilowatts per metric ton of CO2 released. Using numbers from the same organization for 2009 the average US home was using about 5,433.6 kilowatts for heating and cooling throughout the year. So the average US home would be responsible for 2.28 tons of CO2 if using electricity from my state for heating and cooling e
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Because if were going to assume the best case for powering the house, we should assume the best case for producing the cement.
That said, it's still surprising to me how much CO2 is released.
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Is it possible to make cement using cleaner forms of energy?
Is it possible to understand the summary? It's not the energy used to heat the limestone, it's the limestone itself. I suppose they could capture the carbon at the source instead of just burning it off.
About two-thirds of the polluting gases that come from cement production stem from burning limestone...carbon trapped in the limestone combines with oxygen and is released as CO2
Good Job, Editors! (Score:5, Informative)
This is probably the link you were looking for;
https://www.bloomberg.com/news... [bloomberg.com]
I'm glad to see that Slashdot has maintained their high standard of editorial control and oversight all these years.
=Smidge=
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From that article:
One example is pozzolan cement, produced in some of our units in Brazil, and which uses pozzolan as a raw material.
There are also significant deposits of pozzolan in California. Start digging!
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Use the fly ash from coal power plants before digging.
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Use the fly ash from coal power plants before digging.
Fly ash from coal power plants emit radon...heavily, and also usually contain various heavy metals. It can be used in the concrete layer 1 for freeways(i.e. sand, gravel, concrete level 1, black-top, gravel layer 2, and then top-level concrete). Unless it's used in outdoor conditions and in areas where it won't be low lying, it can't be used for buildings or internal areas that have low air flow.
So why don't we switch to... (Score:5, Interesting)
... a type of concrete that doesn't rely on cement? There are plenty of them out there.
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... a type of concrete that doesn't rely on cement? There are plenty of them out there.
Really? I'm not aware of any which are as strong, cheap, and durable as good ol' concrete.
Can you cite any references? I'm aware there are lots of people beavering away at the problem but wasn't aware there were any solutions which were even close to being practical and economical.
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There are. These links should get you started:
https://www.worldcement.com/europe-cis/30012015/zero-cement-structural-concrete-article/
https://en.wikipedia.org/wiki/Geopolymer_cement
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There are. But as it stands none of it complies with existing building codes, and none of it adheres to standard slope and dope tests for consistency. There's also no uniform standards for any form of it at all, in turn there's been no load and limit stress testing done on any of it. So in reality, it's another 20 years out before the committees decide on how to grade it against existing formulations.
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Looking at the worldcement article, it shows "cemfree" (as in cement-free) as a direct replacement for portland cement. From the stats in the article, it performs better than portland cement. It looks like they have done load and sheer testing. Surely if it performs as well as stated, it could be incorporated into building codes quickly (with will). On the other hand the article specifies its use with blast furnace slag, so it might not scale. Also cost is probably more, of course, but this isn't insurmount
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What's the difference between a smart phone and a structure? The liability that comes with passing a building using materials that can't hold the weight. That's why building codes came into being in the first place. If you have 4 million phones out there and one person develops cancer from it, the number is so low that it can't be counted outside of a statistical monopoly. If a building with 300 people in it collapses, there's going to be hell to pay for everyone involved.
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Very interesting. I have to wonder though, if those materials are as good as they sound, why are they not taking off?
I can think of a few reasons. Cost, caution over a new material, availability, building codes. Or maybe they aren't quite as good as they sound. I know I've tried many products on home projects which sounded good but didn't really live up to the glossy brochure.
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that would last in roads, bridges and for buildings, and could be made at scale?
Reminder Roman concrete has less than 1/10 the compressive strength of modern stuff, and if put in freeze/thaw cycle climate desintegrates after 18 - 29 cycles. Not good for most of the world, though if you have nearby volcano for the ash sure would have less environmental impact to use as building material and might be okay idea
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Well, the 2000 year old roman concrete constructions al over Europe disagree with your stupid self invented numbers ...
retards (Score:4, Interesting)
the things built with concrete last good part of a century or more. I'm sitting in my office looking at buildings built in 1920s still in use. Any inferior alternative is going to cause even more CO2 pollution as it won't last as long.
And then that retarded article talks about a replacement for...bricks, which is nothing like structural concrete. fucking hell, when will the green stupidity stop
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Composite wood materials cover a lot of this, the only problem as they're now discovering after being pushed through. Is that they seem not to hold the load as well as they were claimed to be. Especially since most of it is sawdust and plastic made into form under compression. A lot of new houses in the city I grew up in were built using them(basically every house built since 2012 around 1500 single unit homes), they ALL have to be retrofitted with a secondary steel I-beam to carry the load, needless to
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These aren't composite woods; they're pure wood. The wood is compressed and processed to bring cellulose strands molecularly close together. This causes hydrogen infiltration to cross-link between monomers in the polymer chain, which creates something akin to 2D kevlar.
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So working with paper is as dangerous as working with arsenic treated wood? That's basically what you're saying here, the process used to make the wood is similar to that of making paper. I believe you're confused about other dense-wood products which used more dangerous chemicals.
The sodium hydroxide and sodium sulfite weaken the lignan and hemicellulose, just like in the paper process. However, instead of grinding it into dust before processing it into a mash, the beams are left whole. It's then pressure
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Anyway, more interesting news is Google/Sidewalk Labs new proposal for what they're planning to do to the Toronto Waterfront. There's something that might have been very interesting to get slashdot readers' views about.
Since we're talking about changing the status quo of urban development: Google is proposing that buildings in one more
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Anyway, more interesting news is Google/Sidewalk Labs new proposal for what they're planning to do to the Toronto Waterfront. There's something that might have been very interesting to get slashdot readers' views about.
Slashdot did feature that story yesterday, here's a link [slashdot.org]
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The alternatives to conventional cement aren't inferior. Some of them have superior properties. They're more expensive though. Other alternatives are regular old cement, just with the production process tweaked to produce less CO2 or capture what is produced.
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uh huh, please provide links to the equivalent or superior concrete made from them
Re:retards (Score:4, Insightful)
Okay:
https://pdfs.semanticscholar.o... [semanticscholar.org]
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The issue with (Portland) cement isn't just the energy needed to heat it up. You heat limestone (calcium carbonate) to get the calcium, releasing the carbonate as CO2. The opposite process occurs when silicates are weathered by CO2 dissolved in water, and is a major geologic process removing CO2 from the atmosphere. Limestone itself is calcium and carbon dioxide bound up mostly by sea creatures.
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Actually, we use thin slices of concrete for building panels, with fake brick accretions, to make walls. It's very light.
And it replaces bricks.
You must not have been involved in large scale construction this century.
Re:retards (Score:5, Insightful)
So, we should stick with this technique until the end of the world, or should be at least try to think about alternatives? The biggest problem with climate change deniers is that they're status quo opinion is... maintain the status quo. No change, everything is perfect already, anyone who says to do things better is a political stooge...
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So, we should stick with this technique until the end of the world, or should be at least try to think about alternatives?
I've seen the chemistry of cement and over time the exposure to air or water means it soaks the carbon back in. Cement is carbon neutral. The article even hints at this, but you have to know this fact first to see it as they didn't make that explicitly clear. The carbon comes from the fossil fuels burned to heat the clinker.
We don't need an alternative. Maybe we should seek an alternative to the energy sources used to produce and transport it, but the cement itself adds nothing.
Even if the building itse
more BS (Score:2)
Whatever we do the cement itself is a long term net zero CO2 contributor.
That's great news for wind power as the best argument you could come up with was how energy intensive the concrete block was. Basically what you are saying is we should install as much wind power as possible because not only is it carbon neutral the base itself will suck the carbon out of the air.
With such blatant fabrications you must really hold people here in absolute contempt blindseer.
Towering Inferno (Score:2)
Wood burns, Concrete doesn't.
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Wood burns, Concrete doesn't.
You also generally can't build wood buildings more than around five floors tall. I don't think we know how tall you can build a steel and concrete building.
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That's true of untreated wood, but the latest super dense woods are stronger and lighter than steel, and less compressible than concrete. That suggests they'll be useful for building the next skyscrapers, as well as cars and anything else that could use a strong, lightweight material. It's also made almost the exact same way you make paper, so there are a lot of people who should know a whole lot about what needs to be done to produce it cheaply and efficiently.
As far as I'm aware it's not in mass productio
Science! (Score:3)
Say! There's a useful (and intuitive) analogy!
Re:Science! (Score:4, Interesting)
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Eh, it's wrong either way. It cites both Centigrade and Fahrenheit. It can't be 4x both at once, with any sorta-reasonable amount of mind-warping.
Also, "four times hotter" is pretty tough to reconcile with any nonabsolute temperature scale. Maybe something funny with biological perception, but that's getting way nutty.
El Camino? (Score:2)
The report shows that cement produces slightly more CO2 than trucks, but does the "trucks" category include the El Camino? Or the Subaru Brat? Adding those into the mix could tip the scales...
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It's All About Platform For many car experts, the difference between the two is simple: A crossover is based on a car's platform, while an SUV uses the chassis of a truck. The result is that crossovers use "unibody" architecture, meaning the body and frame are one piece, while SUVs use a "body on frame" design. In that case, the body is built separately from the frame and placed together later.
https://www.autotrader.com [autotrader.com]
Not 4x hotter (Score:4, Insightful)
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Which strengthens his point, rather than weakens it. Also, he didn't say the oven self cleaning occurs at 500F, he said "at least 500F", that is, 500F or higher. He said that because his oven goes up to 500F without cleaning, so the cleaning temperature must be much higher.
And what do you know! It is much higher (nearly double, in fact). Just like he said.
This also means no matter how the article was counting it - whether from 0C (seems more likely) or 0K, it was wrong. Starting from 0F gets you the widest
CO2 from production is not whole story (Score:2, Informative)
The production of portland cement emits carbon dioxide, yes.
The setting process reabsorbs about half of the carbon dioxide emitted. The (correct) bloomberg article does not mention that CO2 is absorbed when the product is eventually used.
https://www.abc.net.au/news/science/2016-11-22/concrete-is-a-carbon-sink/8043174?section=science
https://en.wikipedia.org/wiki/Portland_cement#Setting_and_hardening
We need Amdahl's law for climate change (Score:4, Insightful)
OK, it doesn't exactly apply to climate change but work with me.
You look at the chart in TFA. It shows that cars produce 7.9% of CO2 emissions. So we go all hog wild subsidizing electric cars so we can bring that down to...3%? Maybe?
Amdahl essentially said you have to optimize where the time is spent. If you want to address CO2 emissions, you really need to address the big ticket items first. Like that 73% "Other" category.
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See:
https://www.quora.com/What-are... [quora.com]
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Actually, in most of America, a combination of wind and solar with around 0.1% batteries or stored water up an incline running turbines can replace 100% of fossil fuel usage. You can use it to run cars (electrics are now cheaper in half of America and Canada), trucks (yes, 410 mile range offroad trucks with winches, get the optional battery for long trips), trains, tractor trailers, you name it.
In the West, 40-50% of our pollution is from transportation, so it's a big deal here.
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Lol, I literally grew up in PA TX and BC, and live in WA. Don't try to tell me you can't use solar and wind pretty much everywhere in the world, I've literally built bridges and airports as far north as Alaska and as far south as Texas.
I said pumped water up an incline, if you can't use batteries. They use it in places like Norway and Zambia.
It's 2019, not 1969.
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The artificial hydro is pretty ridiculous, but using gravity as a battery doesn't have to be ridiculous. Swap out the electric generator in the wind turbine for a winch that hauls a huge weight up into the air, and attach THAT to an electric generator, using its slow, regulated descent to generate electricity and you've got constant, predictable electricity production out of wind power, which runs even when there is no wind.
There are obvious issues with such a system on the face of it, but my point is that
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For every part of climate change the big ticket is the "other category" the problem with that category is it isn't a big ticket, it's a seasons pass to every event and every sport available*.
*Posted from my smartphone which contributes to that 73% other.
Capture it (Score:2)
I don't understand why we don't capture it or filter it on it's way out of the stack. There are many technologies that can be used to do this, and yet we continue to just blow it up in to the atmosphere to let trees deal with it
https://en.wikipedia.org/wiki/... [wikipedia.org]
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Foiled again! (Score:3)
This is important (Score:2)
Look, we know there are greener methods of making concrete, in fact, worldwide we used to make concrete using mostly local rocks and shells and it worked fine. And then we went on a cement binge, using potash and other high carbon emissions methods.
We're just returning to methods we literally used for millenia, methods that built structures that, for the most part, are still standing.
If we combine the stored carbon taken from both the atmosphere and the oceans in combined sea grass and seaweed beds combine
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Look, we know there are greener methods of making concrete, in fact, worldwide we used to make concrete using mostly local rocks and shells and it worked fine. And then we went on a cement binge, using potash and other high carbon emissions methods.
We're just returning to methods we literally used for millenia, methods that built structures that, for the most part, are still standing.
If we combine the stored carbon taken from both the atmosphere and the oceans in combined sea grass and seaweed beds combined with shellfish, store that carbon in the aggregate concrete that you get mixed with local stones, we can literally start to remove carbon from the atmosphere and oceans.
And as a byproduct, get some yummy shellfish to eat, replacing high emissions beef.
We just need to stop subsidizing the high carbon producing concrete we're using right now. At all levels.
I'll agree to disagree about the shellfish being tastier than beef but you're on the right track as far as there are engineering solutions available. The sooner we start positioning these the better. Part of that positioning has to be not letting some countries off scot-free (looking at China) and saddling Western countries with lots of extra cost. That just accelerates offshoring and further hurts the middle class for no net gain.
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How does reducing the acidity of our watersheds hurt the local economy?
Do you want to pay extra for Canadian lobster and clams and oysters shipped?
Don't you want to save American fisheries and use local materials instead of offshore it?
And careful, don't drop 'im on a fish (Score:2)
Better listen, or the Green New Deal will give you a pair of cement shoes!
Concrete by it's chemical nature produces CO2 (Score:3)
It's not just the high amount of energy, producing cement powder involves basically cooking a mineral mix that offgasses large amounts of CO2 during production in the process of cooking the oxygen out of the mix. It also requires a massive amount of energy because the minerals have to be cooked at about 6000F (IIRC) to produce the klinker that's ground into cement powder. But there is no requirement this energy come from Fossil Fuels like it does currently which is the biggest CO2 contributor to the process, you could do the same with electric heating as the grid moves to renewable. Eliminating the coal or gas that current cement producers use for high heat input would do a great deal to reduce the CO2 contribution.
But concrete also last a very long time, it's also highly versatile and extremely strong. Alternatives to it often involve a massive compromise of either cost, life or strength. Though research continues and will continue for a long time in reducing energy input and improving life because there is a massive incentive to industry to reduce these inputs to improve cost.
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Most plants that are still using fossil fuels are doing so because they're also being used to get rid of waste that either has a low recycling value(tires - especially truck tires, synthetic fiber or 2nd or 3rd generation recycled plastics), has no recycling value(blacktop down the 4th re-layering is pretty garbage, etc), or is considered hazardous(biomedical) to recycle. They're kinda the fill-in gap for the lack of W2E facilities.
the cement plant in my home town is nasty (Score:2)
Alternative (Score:2)
There is an alternative to traditional lime kilns. The material can be separated by electrolysis. The waste product is carbon monoxide instead of dioxide, and is an industrial feedstock.
I'm not aware of any pilot scale plants existing yet, so it's all lab-scale work for now.
And that's just part of it. (Score:2)
There's also the energy required to get those kilns up to those temperatures, which will typically also involve burning energy-dense fuels.
Also worth noting that a wind turbine farm requires about 200 tons of Type I portland cement (that's 2 rail cars worth) to make the 750 cubic yards of concrete used to form the foundation for a single 2MW turbine.
According to EPA, between 900 and 1100 kg (1984 and 2425 lbs) of CO2 is emitted for every 1000 kg (2205 lbs) of portland cement produced in the U.S. This depend
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(and the wind farm will take up almost 400 times as much acreage as a nuclear or coal generating plant will)
Kilns four times hotter? (Score:2)
1,400 C + 273.15 = 1,673.15 K
1,673.15 / 4 = 418.29 K
418.29 K - 273.15 = 145 C
I don't believe your self-cleaning oven works very well.
China (Score:2)
Over 60% of cement is produced by China (and about half of all steel). So the conclusion is always 'China is always the big pollutor'. On the other hand if everything has moved over there it's also pretty obvious that they have to be the big pollutor, big energy consumer and so on, so you kind of have to adjust how you measure things.
With CO2, it's never disappearing. (Score:2)
Part of the solution, of course, is to see what we can do to limit production up front.
But part of it is to see what we can do to limit production downstream too.
Build tighter buildings that require less energy to heat, cool and light.
And capture/sequestration.
They are making forms of concrete that actually involve impregnating it with CO2, or the concrete, during the curing process, absorbs a portion of the cement's carbon footprint.
As well as the various carbon capture schemes out there.
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Why didn't ancient Rome have a global warming problem?
Because they used concrete [wikipedia.org], not cement -- duh. :-)
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Re:Sounds bogus to me. (Score:5, Insightful)
It was indeed produced by heating limestone, a process which gives off CO2 (of course, in the quantities created by the Romans, a relatively insignificant amount). Roman concrete also used pozzolans, which are actually a viable solution for reducing cement in modern portland cement concrete. Pozzolanic concrete takes longer to reach its ultimate strength, particularly with a high ratio of pozzolan to cement, and thus can be limiting to project speed in some scenarios. But the resulting concrete is less permeable and more durable.
The Romans also didn't put a veritable time bomb in their concrete (steel rebar) ;) As the cement in concrete (rich in hydroxides, very high pH) sits exposed to the atmosphere, it slowly reabsorbs carbon dioxide and forms carbonates. This lowers the pH. When it falls too much, it can no longer support a passivation layer on the steel. The steel then rapidly rusts, expands by nearly an order of magnitude, and the concrete spalls out. The only (non-stainless )steel-reinforced concrete safe from this fate is very thick concrete structures, such as dams (where the timescales for carbon dioxide to penetrate to a meaningful depth can be practically geological ;) ).
Of course, we want reinforced concrete, because non-reinforced concrete like the Romans used has basically no tensile strength (they'd sometimes use things like horse hair to add a tiny bit of reinforcement). Epoxy-coated steel sounds great, but doesn't really work well. Stainless steel does, but it's very expensive. FRP rebar is great, where suitable (tensile loads but usually not shear). Easy to work with (lift, cut) whille being incredibly strong, but sharp bends have to be premade. Basalt (BFRP) generally seems better than glass (GFRP) in terms of longevity, while epoxy-coated is generally better than other resins. While very expensive, CFRP (carbon fibre) rebar appears practically immortal.
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Why didn't ancient Rome have a global warming problem?
Because the amount of concrete they used, besides being small in absolute terms, was a minor fraction of their construction. This suggests a solution.
I recently visited Cararra, where the Romans got their marble, and what surprised me is how much of it is still left after 2500 years of mining. The ancient quarries are at the bottom of a whole canyon of pure white marble, thousands of feet high. Some mining is going on at various places in the canyon now, but the supply is nowhere near exhausted. Above the canyon is a whole mountain range, also made of marble.
So let's build marble roads, as the Greeks are right now in the wealthy neighborhoods of Athens, marble dams, marble docks, marble nuclear containments. Much more carbon stays locked up as CaCO3, and we get classier infrastructure than we ever thought possible.
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Sure, if you can convince engineers to give up on the concept of structures having tensile strength and go back to arches and domes without modern safety codes ;)
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Sure, if you can convince engineers to give up on the concept of structures having tensile strength and go back to arches and domes without modern safety codes ;)
But what's not to like about freeway overpasses with Corinthian columns?
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Oh hey look a moron!
Carbon dioxide isn't fucking pollution.
Yeah some is good, more is better, therefore by extrapolation even more is better.
Water isn't pollution either so you should be fine submerging yourself under a mile of it.
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To say that CO2 is not a pollutant is to say that CO2 cannot, in any concentration, render "the air, soil, water, or other natural resource harmful or unsuitable for a specific purpose."
We know that CO2 dissolved in the ocean lowers the water's pH and has negative effects on corals and other calcifying organisms, so to them, CO2 is definitely a pollutant.
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While it may be beneficial to some plants, it also causes the planet to heat up, which in turn melts glaciers, arctic and antarctic ice, permafrost, etc, screwing with ocean temperatures, salinity, and water levels, creating many extreme weather events and massive flooding, especially in coastal areas where a lot of human civilization calls home. These are but a few of the negative effects of having too much CO2 in the atmosphere.
But you prefer to ignore that because, well, it's good for plants.
#MAGA!
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Re:Sounds bogus to me. (Score:5, Informative)
The Roman Empire was tiny compared to the modern environment. World population was at the height of the Roman empire was at most around 450 million, Of that, at most around 70 million people were in the Roman Empire https://www.unrv.com/empire/roman-population.php [unrv.com]. The amount of cement they were using per a capita was also tiny compared to that used by modern societies, by at least an order of magnitude. And if we were only producing CO2 from cement, we wouldn't have nearly the problem we have today anyhow.
It is worth noting that in many respects, the Romans did produce enough industry that it had real environmental impacts in other respects. They were producing so much lead into the atmosphere that we can track the health of their economy by looking at yearly lead levels in Icelandic ice cores https://arstechnica.com/science/2018/05/greenland-ice-cores-track-roman-lead-pollution-in-year-by-year-detail/ [arstechnica.com].
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First, Roman cement used different chemistry from Portland cement (what we use today in concrete)
Second, the Romans used way, way, way less cement than we do.
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Why didn't ancient Rome have a global warming problem?
Because we produce about a zillion times more concrete than the Romans did? Just a guess.
Seriously, it's astounding how much concrete we use. I think the estimate I saw was around a little more than a ton per person per year, globally.
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Seriously, it's astounding how much concrete we use.
Since the invention of concrete, humans have produced about one kilogram for every square meter of land on earth.
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Re: Sounds bogus to me. (Score:5, Interesting)
They did. That's why their empire fell, right?
Actually it was the opposite. Global cooling destroyed the Roman Empire.
Extreme weather events of 535-536 [wikipedia.org].
The Western Empire had fallen in 476. But Justinian, based in Constantinople, was in the process of reconstituting and uniting the full empire. He had reconquered much of North Africa, Spain, and Italy.
Then in 535-536 temperatures fell, crops failed. For reasons that are poorly understood, cooling events tend to be followed by outbreaks of plague. The Plague of Justinian [wikipedia.org] wiped out 30% of the Empire's population. Their barbarian enemies, with more rural and disbursed populations, were much less effected, and were able to roll back Roman conquests.
The global cooling meant higher rainfall and population growth in Arabia. This led to shift of power, which combined with the rise of Islam, led eventually to the end of the Eastern Empire.
Re: Sounds bogus to me. (Score:5, Informative)
That was not one of those long cooling cycles, like the Little Ice Age. Something really big happened in AD 535, and researchers have never determined exactly what it was. For about ten years the Earth turned cold and dark, as shown by tree rings. The leading candidate is a hypothesis that before that year Java and Sumatra were one big island, and an eruption of Krakatoa occurred in comparison to which the 1883 eruption was a popcorn kernel.
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Why didn't ancient Rome have a global warming problem?
Answer 1: Rome wasn't very big by modern standards.
In ancient times the city of Rome had, at its peak, about a million residents. All of what is now modern Italy had 12 million inhabitants. The Empire, stretching from Britain to Syria, had maybe 65 million inhabitants. The entire world in the 2nd Century CE had 200 million people.
Today, the world has almost 40x that population. Shanghai alone has 24 million residents, more than twice the entire population of ancient Italy.
Answer 2: The world uses vastly
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theys was smarter than us...
concrete made with volcanic ash can cost up to 60% less because it requires less cement, and that it has a smaller environmental footprint due to its lower cooking temperature and much longer lifespan. Usable examples of Roman concrete exposed to harsh marine environments have been found to be 2000 years old with little or no wear
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because they population of the planet was a fraction of what it is today, and because those few people didn't have cars, flat screen TVs, computers or fly around the world "on business".
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There are other building materials. Including ones that trap atmospheric carbon in their production. [cnn.com]
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And what the ultra conservatives want is to DO NOTHING, because the end of the world is a good thing when all true believers (ie, Christians who are also ultra conservative) will be raptured and all the evil people will die horribly (let's all cheer for the upcoming pain and suffering like good Christians).
Why not... try to do better? Can we come up with alternatives without yobbos complaining about the reincarnation of Marx?
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And what the ultra conservatives want is to DO NOTHING, because the end of the world is a good thing when all true believers (ie, Christians who are also ultra conservative) will be raptured and all the evil people will die horribly
A coalition seems to be forming between Christians and Greens on this point. Watch for an Epic Final Battle between the anti-natalists and the anti-abortionists. We probably won't get any cool women's costuming out of this one, though.
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It's concrete mix at the factory. The act of wetting concrete mix turns it into cement. Cement will forever be wet. Once is dries, it is called concrete.
You're just wrong.
cement
noun
1. a powdery substance made with calcined lime and clay. It is mixed with water to form mortar or mixed with sand, gravel, and water to make concrete.
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If the costs can be dumped on the middle class and the middle class alone it's okay too.
The poor get subsidies and increased welfare so they'll keep voting for the status quo, the costs are prevented to be too progressive so the rich don't care ... and the middle class can get fucked. Until there's only poor left and that's when we will switch from democracy to totalitarianism.
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For the most part, it's not measurable. However, for beef cattle, it is. Think of it as cow burps.
Simple solution: replace beef as a daily dish with a mixture of tastier:
fish, chicken, range-fed bison (they can eat scrub and burp far less than if they eat grass and it tastes way better, you've not lived until you've had a scrub-fed bison burger, those are yummy!), and whichever grains and vegetables you like.
You can easily reduce the emissions of your meals to 1/10th without sacrificing taste or useable pro
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Well trucks in north america and europe don't really emit SO2 anymore, using blu aka piss ended that. And much like cars, around 20-40%(depending on the engine and load) of the exhaust gas is sent directly back into the combustion chamber to be reburnt as part of the super-charger cycle and intake heating, this is a change previously from channeling rad fluid around the intake manifold to warm up the air. On top of that all trucks made since 2008 have exhaust particulate filters on them, your truck won't