Can We Live Without Concrete? (cnn.com) 407
A combination of cement, water and ground rock or sand, on the surface concrete might seem crushingly mundane. Yet it has defined construction in recent centuries and with it, in part, modernity. From a report: But do we need to re-evaluate our concrete habit for our sakes and the planet's? Production of cement is disastrous for our biosphere, while the degradation of many concrete buildings has some construction experts predicting a colossal headache in the future. There are myriad proposed solutions, such as changing the way we make concrete, creating sustainable alternatives or doing away with it altogether. But would we want to live in a world without concrete? And what would that world look like?
"We make more concrete than anything else, any other product, apart from clean water," says Paul Fennell, professor of clean energy at Imperial College London. One 2015 report estimates that each year approximately three tons of concrete are used for every person on Earth -- roughly, 22 billion tons. To put that in context, a recent study estimated that 8.3 billion metric tons of plastic have been produced, ever. Manufacturing cement, concrete's binding agent, is energy-intensive, Fennell says. Ordinary Portland cement -- the most common form in concrete -- is produced by baking lime in a kiln and emits approximately one ton of carbon dioxide for every ton of cement. Concrete production is responsible for approximately 5% of global man-made CO2 emissions, according to the World Business Council for Sustainable Development.
"We make more concrete than anything else, any other product, apart from clean water," says Paul Fennell, professor of clean energy at Imperial College London. One 2015 report estimates that each year approximately three tons of concrete are used for every person on Earth -- roughly, 22 billion tons. To put that in context, a recent study estimated that 8.3 billion metric tons of plastic have been produced, ever. Manufacturing cement, concrete's binding agent, is energy-intensive, Fennell says. Ordinary Portland cement -- the most common form in concrete -- is produced by baking lime in a kiln and emits approximately one ton of carbon dioxide for every ton of cement. Concrete production is responsible for approximately 5% of global man-made CO2 emissions, according to the World Business Council for Sustainable Development.
Jimmy Hoffa says Yes! (Score:5, Funny)
Asphalt (Score:3)
Yes, there is an alternative (Score:5, Funny)
Re:Yes, there is an alternative (Score:5, Insightful)
HEMP?
I got to ask, do you have a pretensioned hemp beam design in your hip pocket or are you smoking your product too much?
Re:Yes, there is an alternative (Score:5, Informative)
source: http://www.americanlimetechnol... [americanli...nology.com]
Re:Yes, there is an alternative (Score:4, Insightful)
Hempcrete will float in a bucket of water
With sea level rise, that may not be a bad thing. Just let your home float away rather than get flooded and live wherever it lands.
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The problem is that it is the lime production that is causing the problem. Using Hempcrete still involves using lime.
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Ha! This is why I wear a concrete helmet (and codpiece) to go with my concrete shirt!
Comment removed (Score:3)
Why, environmentalists? (Score:4, Insightful)
Why do you propose changes to make everyone's life worse?
Figure out a way for life to actually be better. That's what you did in the 1970s when there was air pollution and water pollution. Air pollution was a problem, not a fear about a possible problem.
Fund some research to create something better than concrete if you want something better than concrete.
Don't ask us to give up living modern lives and mire ourselves in artificial poverty. That's not something Americans or Asians will do. Europeans might.
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You think barking at people because you fear something isn't "sustainable" will persuade them? It won't. You're only talking to yourself. Sorry your audience is so nasty and self-involved.
We cannot live without concrete. (Score:3)
Sorry. We're too dependent on it as a building material.
Now, this doesn't mean we can't modify concrete to reduce/eliminate some of it's deleterious effects on the environment.
But, in the end, we still need concrete in whatever forms it eventually takes.
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No. If we want water and food, we pretty much NEED concrete.
Our society requires it.
Unless you're a farm owner with a sufficient water resource on your property...
If Only (Score:2)
by baking lime in a kiln and emits approximately one ton of carbon dioxide for every ton of cement.
If only there was some way which we could head a kiln without hydrocarbon fuel....Oh wait there are lots of ways we could do that...So Its not really cement manufacture that is the problem is it? Sounds more like an problem of how we are choosing to source the energy for it.
Re:If Only (Score:5, Informative)
The lime emits CO2 as CaCO3 converts to CaO. It does not absorb back into the material in the use-case of Portland Cement.
Lime plaster, which I posted about further down, DOES bring that CO2 back into the material (as it cures by Ca(OH)2 converting back to CaCO3+H2O with the introduction of carbonic acid, i.e. CO2 dissolved in a thin film of water).
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The heat input is one part of the problem, but you are calcining the limestone, which emits significant CO2 as well. Not sure about the overall reactions and what else comes into play.
As for the heat input, it would be a challenge to make a solar kiln for 1300C, but you still have the thermodynamic limitations of needing to heat something up really hot and then cooling it back down to ambient temperature.
And it prevents us from using wood (Score:2)
Concrete also causes us to use less wood. While on the one hand that's a good thing since even older forests are a great carbon sink, on the other hand it wooden houses are a really great way of removing carbon from the biosphere for quite a long time; the average wooden house stores the equivalent of 20 tonnes of CO2. Building 400 million wooden houses would compensate for the entire CO2 surplus in the biosphere (or at least in the atmosphere). In theory ;)
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This is an important point. Houses made from biomass materials, including Strawbale, sequester quite a bit of carbon and keep it dry so it doesn't rot in the wild (driving off CO2 over time).
Strawbale? Watch out piggies (Score:5, Funny)
When I was little, I was told a house made of strawbale and another made of wood failed to survive severe weather, particularly strong rain[1] and wind.[2] Or have I been duped all these years by the brick construction lobby?
[1] "The Pros and Cons of Straw Bale Wall Construction In Green Building" [buildingwi...reness.com]
[2] "The Three Little Pigs" by Joseph Jacobs [wikisource.org]
Concrete is over-used for convenience (Score:5, Informative)
The crux of the article was Rammed Earth, which I think is a great replacement for concrete for certain applications (some load-bearing vertical walls mainly). Dirt cheap, clay & sand.
Some applications of concrete are frivolous and I think can be replaced. The reason is mostly cost and availability, and the current labor force is skilled with using it. The wall-facade material of choice before concrete, and before gypsum drywall, was Lime plaster. For wet or exterior applications I am in favor of using lime as it is less carbon-intensive than concrete and produces a beautiful lighting effect from birefringence (https://en.wikipedia.org/wiki/Birefringence), owing to the tiny calcite crystals that form when it cures back into limestone. See http://www.sapphireelmtravel.com/travel-journal/chefchaouen-morocco-blue-city for an example.
There's also benefits to the water vapor breathability of lime vs. concrete (which doesn't breathe, unless it's cracked).
Producing Lime plaster is less carbon-intensive than cement as it requires lower temperatures, and the CO2 driven off by the limestone during calcining (which happens in Ordinary Portland Cement production as well) is mostly re-absorbed by the slaked lime as it cures back into limestone (leaving the net CO2 footprint coming from the fuel used to calcine the lime, if coal or natural gas or wood is used, although perhaps decades into the future someone comes up with a nuclear-fueled kiln, electric or high temp gas or whatever).
The big downside to lime plaster is the time it takes to cure, and what that does for timelines and labor costs. It usually requires multiple thin coats (with a week or more between =3/8 inch coats - need time for CO2 to reabsorb as carbonic acid which also requires the material be damp, but not covered in water) which blows up the labor costs.
https://johnspeweik.com/2011/10/27/the-lime-cycle/
The upside to using lime plaster is there's a wealth of historical information on what to do with it... much of the "bling" of the pre-1800's architecture can be traced to the use of lime or limestone.
E.g. the Moroccan process of Tadelakt - https://en.wikipedia.org/wiki/Tadelakt
Venetian plaster - https://www.architecturaldigest.com/story/venetian-plaster-trend-guide
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Whilst lime plaster is a nice facade, you still need a means of structural support behind it.
So how do you build ten storey buildings, shopping centres, car parks, railway sleepers, bridges, stormwater pipes and a million other little bits of modern life without concrete? Are steel and other structural alternatives more resource-intensive than concrete over the whole lifecycle? That's the kind of questions I want to see answered, not a laser-focused hit piece on concrete.
5% (Score:4, Insightful)
Concrete != cement (Score:3)
FIVE PERCENT of global CO2 emissions for cement production.
Captain pedantic here but it is NOT cement. It is concrete and they are not the same thing. Every time you conflate the two terms a civil engineer looses his wings. Cement is an ingredient [ccagc.org] in concrete but concrete is not cement.
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From the summary, it was concrete production that was fingered as the 5% contributor, not concrete use in general. In fact, the summary even states:
Manufacturing cement, concrete's binding agent, is energy-intensive, Fennell says. Ordinary Portland cement -- the most common form in concrete -- is produced by baking lime in a kiln and emits approximately one ton of carbon dioxide for every ton of cement.
That sounds to me like pretty much exactly what the parent stated. They were correct to indicate cement as the big CO2 driver in concrete production, based on the article summary. Maybe read what was actually said before getting all pedantic?
Re:Concrete != cement (Score:4, Informative)
Captain Pedantic gets two demerits. The source of the CO2 production in the production of concrete IS from that ingredient called "cement". Sand, aggregate and water contribute nothing to CO2 release.
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Not necessarily; if you believe in carbon capture then a cement kiln might be a logical place to do it. The only real issue is the CO2 is quite hot and mixed with a lot of other nasty stuff-- but maybe not much of a challenge compared to a liquid CO2 plant using refinery feed gas.
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Concete Manufacture Does Not Have To Produce CO2 (Score:5, Insightful)
The post is based on a false premise: that CO2 production is inherent in making concrete. There is already a process to not do that. Further, most of the CO2 is made from generating the heat to make the concrete. Most of that CO2 production is low-hanging fruit to eliminate.
This is just more chicken little chicken shit.
Re:Concete Manufacture Does Not Have To Produce CO (Score:5, Informative)
Sorry, forgot the link:
https://phys.org/news/2012-04-... [phys.org]
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That is very cool. Thanks for sharing!
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An electrochemical process? Thank goodness we have unlimited supplies of CO2-free electricity available.
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I do not understand how one would convert limestone, CaCO3, into the primary ingredient of portland cement, CaO, without releasing a nontrivial amount of Carbon Dioxide.
Could you explain what I'm missing?
THanks.
No, and fuck off (Score:2)
Because we know you'll also object to wood, steel, aluminum, carbon fiber, plastic, bone, fiberglass, or any other structural material we can come up with. Magical unobtanium which can be produced and used at scale without any environmental effects doesn't exist and never will.
There IS a place made mostly of dirt! (Score:2)
It is called North Dakota. Go there sometime. Then you will be getting yourself some Concrete instead!
Economic concerns drive building materials (Score:2)
Two concrete articles today! It's great.
Talking about environmental impact is great and all, but we will use concrete until something supplants it due to economics. Right now we are seeing real interest in tall timber construction, and while the designers will tell you about potential environmental benefits the real driving force is potential dollars - it's expected to be faster and cheaper than concrete and steel. Concrete construction is energy intensive as the article points out, but it's also surprisin
We use concrete because it is cheap (Score:5, Insightful)
We use concrete because concrete is cheap. Really, really, cheap. You can get similar results with other materials for many applications but there are few materials that are as readily available, easy to use, and inexpensive as concrete. Come up with a material with usable performance and a similarly low price point and you can be sure we would use a lot of that.
FYI one ton of concrete is a piece roughly 0.42m^3. So they are saying we each use a piece of concrete about the size of a desk each year.
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We also use it because it's relatively durable and pest-resistant. Compare and contrast, frex, a wooden foundation vs a concrete foundation in an area with ground termites.
[for the uninitiated, ground termites can live just about anywhere that doesn't both hit -40F every winter and isn't regularly treated with discouraging pesticides.]
wood (Score:2)
no and we won't be able to make it soon. (Score:4, Informative)
Believe it or not it has to do with sand.
Sand with sharp edges.
Sand from the desert is round and is not good for cement.
So stop worrying about the CO2, energy, etc needed to make cement. we are running out of sand.
https://science.slashdot.org/s... [slashdot.org]
http://www.spiegel.de/internat... [spiegel.de]
https://www.npr.org/2017/07/21... [npr.org]
IOW: we are fsked. Roads, buildings, bridges, etc will have to be built with something else and nobody cares to even worry.
We could just use rocks for building (Score:5, Interesting)
Modular construction (Score:2)
Use aerated concrete (Score:2)
Regular concrete for a lot of applications is way too strong (say non-load-bearing walls). So switch to aerated concrete, AAC for that.
https://en.wikipedia.org/wiki/... [wikipedia.org]
Complaints and alternatives (Score:2)
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New Concrete Using Graphene (Score:2)
This article just appeared claiming a concrete twice as strong as existing concrete while releasing less CO2.
https://inhabitat.com/ [inhabitat.com]
This is based on a Mythconception (Score:3)
There is a mythconception touted by some that concrete is bad. That is totally wrong. Concrete is almost all rock and sand. There is very little cement (the material at issue) in it. And the long term net effect is that concrete is a benefit because concrete structures last for a very long time, measured in hundreds to thousands of years as opposed to wood built structures that last mere decades.
Additionally, if you properly design your structures you can make concrete even greener by eliminating the need to heat or cool the buildings. I have done this with both our home and our butcher shop. Concrete offers tremendous thermal mass which can store the heat from summer over to winter to keep the building warm and store the cold from winter over to summer to keep the building cool.
I have done this with our home which masses about 100,000 lbs inside an insulated envelope. Even in our extreme cold climate in the central mountains of northern Vermont we don't have to heat or cool our house. It will stay in the mid-40's through the winter and rise to the 60's in the summers. We can optionally raise that to the mid-70's in the winter with just 0.75 cord of wood (a very small amount for those of you who don't use wood heat), which is a renewable resource from dead wood on our land.
Our butcher shop is built along the same lines but far more massive at 1.6 million pounds of concrete built in six shells with insulation between each. We have no heating system and no refrigeration system to chill our cutting room, etc. We've been operating for three years under Vermont state inspection and on May 1st we received our USDA license. I've been told repeatedly by the USDA and other government officials that they are amazed by our facility because it is so good, requires so little maintenance, is so easily cleaned and how it naturally stays the right temperatures. All of that is about design. I love math. Math applied is even better - it solves real problems.
Concrete is not evil and is not the cause of global warming. Properly used concrete and cement are the solution to reducing pollution and cutting energy consumption.
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Concrete is heavy, and plastic is light. So by weight, it seems reasonable that "we" produce more concrete than plastic.
Is that why there's more gold produced than concrete?
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Concrete is heavy, and plastic is light. So by weight, it seems reasonable that "we" produce more concrete than plastic.
Is that why there's more gold produced than concrete?
I don't think we produce any gold. The alchemists lost.
Summary is dense too (Score:5, Interesting)
They compared concrete to plastic, but most of the weight (about 85%) in concrete is sand and rock. Although even with that the world uses a lot of cement.
Rather than looking for alternatives I'm guessing this is a plea to make the manufacture of cement more environmentally friendly (green energy for the heat, capture the CO2, etc.). That would make far more sense than trying to find an alternative to concrete.
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Capturing the CO2 was my first thought. It's being released in centralized factories, surely that's about as easy a target for carbon capture as anything?
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There was a recent item about carbon capture with peridotite [technologyreview.com] (but I am linking to an older story about it). Peridotite exists in huge surface formations in several areas of the world.
Perhaps an additional stage could be added to cement manufacture wherein the CO2 released is passed through a second kiln loaded with quarried peridotite to capture the CO2, producing calcium carbonate (again). Since calcium carbonate (limestone) is a starting material processed in the first kiln it could possible be recycled
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Capturing CO2 is almost always a fake solution. The only exceptions are when it's economically viable. I think the people who make liquid nitrogen already do that, but the demand for CO2 isn't that high. Fire extinguishers, carbonated water (seltzer water, not soda water), dry ice, a few chemical processed, dry cleaning. I'm sure that there are some uses that I've missed, but there aren't many, and they aren't high volume. If there were more demand, they wouldn't be pretending to store it safely underg
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It seems like finding a better form of concrete is the reasonable solution for those of us who aren't hippy freaks. And if we can elminate CO2 from other production, or significantly reduce it, that's also a good choice. Living without concrete is hard, living with electric cars is not so hard (transportation is 28% of CO2 production). Particularly if we can increase solar, wind and hydro production of said electricity (another 28%).
I guess I'd focus on that >50% first that has some really low hanging fr
Re:Only if you like suburban sprawl (Score:4, Informative)
Yeah, nah [fortune.com].
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Unless they use bamboo (or some other fast growing "wood") I would say this isn't really much of a solution to using concrete (I do realize you were just refuting the idea that you need concrete to go higher than four stories though).
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The words "set to", "will", "planning", and "plans" come up a lot that article. They aren't going to build it for another 20 years, and it's anticipated to cost twice as much as a conventional high-rise.
Granted, there is a link in the bottom of that story to an existing wooden building that is 18 stories tall. It's in Vancouver [archinect.com]. Notice what's at the core of that building? Two giant concrete towers. Underneath it? A concrete pedestal. GP's point stands as stated.
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Re:Only if you like suburban sprawl (Score:4, Interesting)
Concrete is the reason we can build things higher than four stories.
Silly me.. Here I thought that was steel and elevators that did that.
Concrete is nearly useless without steel. Huge compression strength, itty-bitty tension strength. Yea, you can pile up blocks of concrete and "build something" but without steel you won't be able to do much more than a pyramid.
Re:Only if you like suburban sprawl (Score:4, Interesting)
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Yea, heaven help those who live in the basement... Like I said, you can stack blocks of concrete up and build stuff, but the kinds of things you can make is going to be pretty limited because you have to use concrete in compression, but you cannot use it in tension. So no long beams of concrete holding up large expanses and creating open covered spaces.
It's the very reason cathedrals built in the middle ages had the shapes they did and the very narrow open spaces under roof. You basically build a pyrami
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Like I said.. It takes a lot of material to build this way and you basically are building a pyramid with internal voids. All your materials must be used where they are under compression.
Yep, you can create open spaces, but such buildings are very difficult to build, use lots of material and pretty limited in size based on their weight and the load bearing capacity of the materials being used. Open spaces weaken the structure and stress the materials and you quickly reach a practical limit based on enginee
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Concrete is nearly useless without steel.
Yet most of the largest constructs built prior to WW2 were essentially concrete without steel. Fancy that! I do not deny that steel makes it easier, but concrete by itself is an amazing material, especially when put into brick form, arched, or used with wood. Proof: what I've already posted - the Colosseum and St. Peter's Basilica, for starters. Hoover Dam and Grand Coulee Dam - two of the biggest dams built in the US - are also done without steel. Need I go on?
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That building he keeps talking about wasn't put up yesterday. In two words: solved problem.
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Look, you lost the argument, give up already.
That's a bold statement, considering it's flat wrong.
Expensive and difficult are your counter arguments? As if smelting, forging, cutting, lofting, and welding steel are super cheap compared to the cost of... a rock?
If stone is a better building material why don't we use it any more? Yes, I'm sure you can find me a new building made of stone. I'll find you 10000 more that aren't. We don't use it because we have found better ways to build structures.
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Re:Only if you like suburban sprawl (Score:4, Funny)
Elevators are the reason we want to build things more than four stories high.
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It itsn't. Steel is. And we can build really high with wood these days as mentioned by a comment above.
Increase in carrying capacity (Score:3, Informative)
Ergo, humanity must not exist, since we could not have existed before concrete.
The truth is probably somewhere in the middle. Some of us could have existed, others not. To understand why, ask yourself: What was the human population before the invention of concrete, and what is the human population now? At least some of this additional carrying capacity probably arises from inventions that rely on concrete.
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Just Wow.. I wonder how you are going to make clinker using electricity?
I suppose there might be a way, but it seems to me that firing the kilns with Natural Gas to produce clinker (the stuff they grind into cement to make concrete with) is the most efficient approach at this point.
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Electric furnaces are a thing, but are silly from an efficiency perspective. Something like half of consumed industrial power is "primary thermal", meaning fuel burned directly for heat, no electricity involved.
Consumer and commercial power may one day be provided entirely by solar with batteries, but not industrial power (well, not Earthbound industry, orbital one day). Maybe one day fusion will stop being 20 years away.
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as far as I can tell, this summary is blaming concrete because the energy source is dirty. What if the energy came solely from turbines, dams, nuclear power, or some other form of clean energy?
Here's the thing. The reason that the "energy source is dirty" is because there's a whole pile of stuff we don't recycle(it's too expensive, or too dangerous, or too hazardous and so on), in turn we use during the making of cement. Tires, some plastics, medical waste, non-recycled automobile fluids, various hazardous compounds from industry just to name a few, it's all used as fuel and scrubbed to reduce emissions when you're baking the lime. The remainder ash(fly ash) is mixed in with the cement in vari
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Sorry, but we *don't* have a fully sustainable harvest cycle. We're getting a lot better, but we still need to improve a lot. During parts of the cycle there's a lot of soil erosion. It's still not clear how many times we can run through the cycle on a particular plot of land before wearing it out. And that's when there aren't any problems, like, say, pine beetles moving into a new area. Or droughts combined with fires.
Sorry, but we do. Why don't you go take a trip and find out for yourself. I'll remind you that the problems of "pine beetles" and "droughts and fires" are caused by current policies where they don't allow direct burns, but rush to put out fires. Which furthers the problem of accumulated ground material that's highly flammable. I mean, I've seen areas here in Western Canada where the ground clutter is over 3' deep and there hasn't been any burning done in 80 years.
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It's not just the energy source. The kiln produces CO2 from limestone as the miracle of chemistry turns it into cement.
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as far as I can tell, this summary is blaming concrete because the energy source is dirty. What if the energy came solely from turbines, dams, nuclear power, or some other form of clean energy?
Fossil fuel combustion is only part (40-50%) of the problem with making cement. The other part, 50-60% is this chemical reaction: CaCO3 -> CaO + CO2. The calcium oxide produced is a key part of cement. Not using fossil fuels would cut CO2 emission by about half, but is not a complete solution to the problem.
Actually cement - over the course of decades - reabsorbs about 40% of the CO2 released by the burning of limestone as it post-cures. So the net CO2 release from concrete is commonly overstated by abou
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Depending on your exact expectation of "never, ever be going away" I would have to say you are wrong. It may not be going away in the immediate future but I'm not sure it will still be used 1000 years from now. If it is then will it still be used 1 million years from now? 1 billion years?
Re:Betteridge's law of headlines (Score:5, Interesting)
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"We make more concrete than anything else, any other product, apart from clean water"
Obviously the best question to be asking is "can we live without it?"
Checks out.
Not quite (Score:2, Interesting)
Betteridge's law is about the possibility of "excitement", it works on titles with the form "could it be exiting?" (the answer is no). This title is almost the opposite, concrete is so normal that we wouldn't even think of a world without it so the question is reversed, "would it boring if we stopped doing this normal thing" is used instead. This trick relies on peoples assumption that changing the status quo will be big and "exiting", when normally it is boring, guiding people into assuming an exiting a
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Agenda 21 was to have the population live in high-rise high-density urban centres while the rest of the land surface area was returned to nature. To achieve this goal they wouldn't bother dredging rivers or build sea defences against coastal erosion but they did sell off the flood plain land to property developers.
Comment removed (Score:5, Insightful)
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I'm confused, why would the parasitic rich want to solve the parasite problem?
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Re:It doesn't matter (Score:5, Informative)
"Concrete is as good as stone, and you see how long ancient Greek, Roman, and Egyptian stone structures have stood. "
The Romans built almost everything with concrete, also the 'stone' structures you mean. The stone was usually only a thin outer shell to contain the poured concrete.
Also their concrete was (and is) much more resilient, it didn't crack as easily as our Portland variant. Portland cement wouldn't last for millennia, it sometimes doesn't take decades to make it fail.
"Recently, it has been found that it materially differs in several ways from modern concrete which is based on Portland cement. Roman concrete is durable due to its incorporation of volcanic ash, which prevents cracks from spreading."
https://en.wikipedia.org/wiki/... [wikipedia.org]
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Yes, and here's a previous Slashdot story about the apparent discovery of what made Roman concrete so durable, just a few years ago: https://tech.slashdot.org/stor... [slashdot.org]
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Most of the time you move concrete thrice. Once to get the components to where it is being 'made', and again to get it where it is being used.
And after a while, you may, may remove it and either recycle or dispose of it.
Transportation costs are a real thing, but in this instance I doubt these costs are such a big deal. Now steel has advantages, perhaps, in production costs and recycling, but sometimes you need strength and mass, and until we rethink design, concrete is the solution.
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Re:Come on, Editors (Score:4, Interesting)
Like all things environmental.
What are the alternatives? Wood, Bricks, Stone...
What are the Pros vs Cons of these alternatives? Renewable, Deforestation, difficult to ship, difficult to work with, limitation on what can be made...
Can a hybrid approach be done? Are we using more Concrete then we need? Do we really expect this building to span the Melania?
Where I live there is an abandoned factory made from Concrete, it is an eye sore in the city. However it is nearly indestructible, and will cost too much to knock down.
Re:Come on, Editors (Score:5, Funny)
Even worse:
each year approximately three tons of concrete are used for every person on Earth -- roughly, 22 billion tons.
Every year we are adding 22 Billion tons to the weight of the earth. Sooner or later, that's going to start having an effect.
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Every year we are adding 22 Billion tons to the weight of the earth. Sooner or later, that's going to start having an effect.
Like the hollow center collapsing?
I knew Journey to the Center of the Earth was more fact than fiction!
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What are the alternatives?.
We don't need an alternative to concrete. We just need an alternative to fossil fuel fired kilns. Kilns can be nuclear or solar, and since they use pure heat, there is no Carnot inefficiency. They could be used in a co-generation process, using low grade waste heat to warm the lime, and high grade heat to finish.
Cement production could be used as a nuclear load leveler. During periods of high electric power demand, send the heat to a turbine. When demand drops, switch the heat to the kiln.
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Well, that knocks down the building, and now you have a pile of rubble that is either left to be an eyesore or carted off to be landfill.
It would be much better if the building could be reused, but often that isn't really possible. OTOH, I had a friend who lived in an authentic adobe house...which was a real nuisance, because electrical wiring an plumbing had to be on th exterior of the walls unless you wanted to put in false flooring or some such, and even then to get them from one room to another require
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And it looks like practically every western city just before its historical Big Fire.