Slashdot Mirror

← Back to Stories (view on slashdot.org)

Cement is the Source of About 8% of the World's Carbon Dioxide Emissions (bbc.com)

Posted by msmash on from the concrete-proof dept.

Concrete is the most widely used man-made material in existence. It is second only to water as the most-consumed resource on the planet. But, while cement -- the key ingredient in concrete -- has shaped much of our built environment, it also has a massive carbon footprint. From a report: Cement is the source of about 8% of the world's carbon dioxide (CO2) emissions, according to think tank Chatham House. If the cement industry were a country, it would be the third largest emitter in the world -- behind China and the US. It contributes more CO2 than aviation fuel (2.5%) and is not far behind the global agriculture business (12%). Cement industry leaders were in Poland for the UN's climate change conference -- COP24 -- to discuss ways of meeting the requirements of the Paris Agreement on climate change. To do this, annual emissions from cement will need to fall by at least 16% by 2030.

89 of 185 comments (clear)

  1. That's a trade I'm willing to make. by olsmeister · · Score: 2, Insightful

    If you're looking to cut CO2 emissions, please look elsewhere. Concrete is pretty much essential to life as we currently know it in the civilized world. Let's go back to building with wood and replicate the 1906 fire in San Francisco...

    1. Re:That's a trade I'm willing to make. by PolygamousRanchKid+ · · Score: 3, Funny

      Let's go back to building with wood and replicate the 1906 fire in San Francisco...

      Well, instead of wood, we could try sticks and straw.

      But then we might get a knock on the door:

      "Little pig, little pig, let me come in."
      "No, no, by the hair on my chiny chin chin."
      "Then I'll huff, and I'll puff, and I'll blow your house in."

      Personally, I'll make my house of bricks.

      --
      Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
    2. Re:That's a trade I'm willing to make. by Thelasko · · Score: 1

      If you're looking to cut CO2 emissions, please look elsewhere. Concrete is pretty much essential to life as we currently know it in the civilized world. Let's go back to building with wood and replicate the 1906 fire in San Francisco...

      Oregon is already going in that direction.

      --
      One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
    3. Re:That's a trade I'm willing to make. by Headw1nd · · Score: 4, Interesting

      It is far from a given that cement production has to release as much CO2 as it does now. I am in the building world, I will assure you nobody is giving up concrete, but there is a lot of research going into reducing the carbon footprint of cement, along with increasing its strength and decreasing its weight. Most concrete in this world is used to support other concrete, affordably reducing weight would go a long way to reducing demand.

    4. Re:That's a trade I'm willing to make. by jellomizer · · Score: 1

      Because it is a popular building material, it doesn't mean we should look at ways to reduce its CO2 impact. I have been getting a lot of All or Nothing type of debate lately. So it produces 8% of the worlds CO2. If we can cut in by a quarter, then you could reduce 2% of carbon emissions.

      We have people at work, doing their job very inefficiently and over complicate the process, they won't accept a new way, because this method was already an improvement on what it was like before.

      --
      If something is so important that you feel the need to post it on the internet... It probably isn't that important.
    5. Re:That's a trade I'm willing to make. by jellomizer · · Score: 1

      How many people will get shot for trying to forcefully relocate citizens from the country to the city?

      --
      If something is so important that you feel the need to post it on the internet... It probably isn't that important.
    6. Re:That's a trade I'm willing to make. by AmiMoJo · · Score: 1

      There are other alternatives than just wood, although even wood can be used safely if treated properly.

      For example rather than using concrete blocks you can use polystyrene blocks. They are great insulators too. Obviously not so strong but great for using inside walls.

      Concrete is cheap but as soon as we find something cheaper it will be replaced. That's always what kills off old tech.

      --
      const int one = 65536; (Silvermoon, Texture.cs)
      SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
    7. Re:That's a trade I'm willing to make. by Chas · · Score: 3, Informative

      There are several ways to fix it.
      There are ways to replace the portland cement.
      There's also ways to SEQUESTER CO2 in concrete as well.
      There are also forms of concrete that actually ABSORB CO2.

      --


      Chas - The one, the only.
      THANK GOD!!!
    8. Re:That's a trade I'm willing to make. by Rei · · Score: 5, Insightful

      Modern concrete includes the seeds of its own demise - its steel rebar. The steel is protected from corrosion by the highly basic environment of the concrete, but the slowly cement begins being converted back to limestone by absorbing carbon dioxide from the atmosphere. This lowers the pH. When the pH drops too much near the steel, it begins quickly rusting, expands nearly tenfold, and the concrete spalls out. Indeed, minimum wall thicknesses in many places have nothing to do with required compressive strength, and are rather just to protect the steel.

      FRP (fibre-reinforced plastic) rebar, by contrast, not only tolerates a more neutral pH, but actually prefers it. It's not a direct drop-in replacement (it bears tensile loads, but is poor (esp. when not using CFRP) at shear and compressive loads). But you can use small amounts of stainless rebar wherever you can't use FRP. Also, while you can bend FRP rebar along gentle curves, it can't handle sharp curves; you order pre-shaped curves for that. On the other hand, it's much easier to work with than steel - it's lightweight and you can cut it with a simple reciprocating saw.

      FRP rebar doesn't rust, but its strength does decrease with time. However, most of its strength loss is early on, and the rate of loss slowly declines with time. Among FRP rebar, fibres are generally (from worst to best): GFRP (glass), BFRP (basalt), AFRP (aramid), and CFRP (carbon). CFRP is awesome stuff... suffers almost no degradation in any conditions (even less than its plastic binder)... but it's currently very expensive. IMHO, BFRP is the best balance of price versus mechanical properties. As for binders, epoxy binders are best. Sometimes you see uncoated products (I've even seen a structure entirely reinforced with just bare roving), but that's not ideal for longevity.

      --
      That last paragraph contained spoilers, so if you don't want spoilers go back and don't have read it.
    9. Re:That's a trade I'm willing to make. by Rei · · Score: 3, Informative

      wall thickness is not to protect rebar. commercial building codes specify 1.5" from rebar edge to concrete surface for bar size #2-#6 typically (with almost no exceptions) and 3" for earth exposed rebar (up to #6 or 5/8" dia rebar

      You just contradicted yourself there. That minimum 1,5" / 3" is to protect the passivation layer on the steel (whether you realize that or not). The thicker the layer, the longer that carbonation takes. In ideal conditions, carbonation depth (in mm) progresses at a rate roughly: (-3,59 + 9 * W/B) * sqrt(t) where W/B is the water/binder ratio and t is time. However, a number of factors can significantly accelerate carbonation, so large margins need to be allowed for.

      --
      That last paragraph contained spoilers, so if you don't want spoilers go back and don't have read it.
    10. Re:That's a trade I'm willing to make. by rtb61 · · Score: 1

      You would look exactly there. You just need to fix the carbon dioxide emission, get it back into a solid, say crystalline form, that can be added back into the Portland cement.

      I would think biological treatment could work, a massive structure containing, algae or bacteria to take up the carbon dioxide and like tiny little factories, make it into something we can use and as such sell.

      Turn something bad into something useful. Two useful products, sodium carbonate and carbon tetrachloride, so just add salt water to waste carbon dioxide, the required chemical processes and you are done. Those are both manufactured chemicals, so bloody manufacture them next door to portland cement plants that a close to the sea.

      Perhaps, just possibly, complementary chemically manufacturing should be a thing, some ones trash can be another persons treasure.

      --
      Chaos - everything, everywhere, everywhen
    11. Re:That's a trade I'm willing to make. by dcw3 · · Score: 1

      "When the pH drops too much near the steel, it begins quickly rusting, expands nearly tenfold..."

      Huh...expands tenfold???

      --
      Just another day in Paradise
    12. Re:That's a trade I'm willing to make. by Headw1nd · · Score: 1

      I'm sure he realizes why the rebar is kept back from the surface, what he's saying is that there is no difference in the depth of rebar on a 6" thick wall vs. a 24" thick wall, in either case it will be placed as close to the surface as code allows. I think what you are saying is that if you were able to place rebar closer to the surface you could often go with a smaller member, since you generally have a surplus of compressive strength with the amount of concrete used. (or maybe you want to use beams with 2" webs?)

      On a side note, it' good to see you are still around this accursed place.

  2. Re:Concrete? by Calydor · · Score: 1

    You mean like Scooby-Doo real estate developers?

    --
    -=This sig has nothing to do with my comment. Move along now=-
  3. Solved problem by SuperKendall · · Score: 5, Informative

    Concrete contributing to CO2 has been known for a while - that is why at this point there are a lot of solutions to that problem, including concrete variants that sequester or even absorb CO2.

    Notice how old some of the results in that search are...

    If CO2 is really a problem, local governments will seek to adopt some of those ideas.

    --
    "There is more worth loving than we have strength to love." - Brian Jay Stanley
    1. Re:Solved problem by xxxJonBoyxxx · · Score: 1

      >> If CO2 is really a problem, local governments will seek to adopt some of those ideas

      The main problem is that two of those "local governments" are India and China - until we figure out a way to get them in check we're still on a path to be very screwed.

    2. Re:Solved problem by jellomizer · · Score: 1

      "If CO2 is really a problem, local governments will seek to adopt some of those ideas."
      What kind of statement is that? Local governments are extremely short sighted. My town isn't in a flood plain why should I care about global warming?
      Local governments may make a bigger deal with Air Quality issue such as smoke and smog, but at the current levels CO2 is mostly harmless to people.

      That is the problem with CO2 and Global warming. It is a real problem, but it isn't easily seen, and to fix it requires a lot of changes, which we as humans don't want to do.

      --
      If something is so important that you feel the need to post it on the internet... It probably isn't that important.
  4. Well known... by apoc.famine · · Score: 5, Informative

    Not sure how this is suddenly news. It's been called out since the very first IPCC report, and known long before that.

    This is part of why nuclear power and hydroelectric power aren't exactly green. Far better than fossil fuels, sure, but much worse than an equivalent solar or wind farms in terms of CO2 release. The amount of concrete used in both nuclear plants and hydroelectric dams is massive. It dwarfs the pads for solar panels and wind turbines.

    But like everything, it's complicated. Turns out that over decades, concrete actually absorbs a large amount of CO2. It seems to be close to half that released when making it. If carbon capture could be used during production, over its lifetime, concrete could become carbon negative. And alkali-activated cements seem to be on the horizon, taking industrial CO2 byproducts and making them into concrete-like structures.

    --
    Velociraptor = Distiraptor / Timeraptor
    1. Re:Well known... by Solandri · · Score: 4, Informative

      The amount of concrete used in both nuclear plants and hydroelectric dams is massive. It dwarfs the pads for solar panels and wind turbines.

      Actually I did the calculations on this a few years back. Per GWh of energy generated, wind turbines use roughly an order of magnitude more concrete (and steel) than nuclear plants. You have to understand that wind turbines very rarely operate at full capacity like a nuclear reactor does. The actual electricity production of nuclear plants averages about 90% of their nameplate capacity. For onshore wind it's about 25%. So to generate the same amount of power over the course of a year as a single 1 GW nuclear reactor requires about 2500 1.5 MW wind turbines (3.6 GW capacity). And the steel and concrete for that many turbines far exceeds the requirements for the single nuclear plant. It also drives up the maintenance cost for wind far above that for nuclear, even with all the regulations covering nuclear. (In fact most of the wind-related deaths are due to maintenance personnel falling from turbines.)

    2. Re:Well known... by Thelasko · · Score: 1

      The amount of concrete used in both nuclear plants and hydroelectric dams is massive.

      It's also a one time fixed "cost" that can be amortized throughout the life of the plant. Where as the CO2 production from fossil fuels is directly proportional to the amount of energy produced.

      Keep those nuclear plants and hydroelectric dams in service longer, and they become greener and greener.

      --
      One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
    3. Re:Well known... by Areyoukiddingme · · Score: 4, Informative

      How exactly does concrete produce CO2? Is it an essential part of production - or merely a result of heating in furnaces traditionally powered with coal?

      It is an essential part of production of Portland cement, the most common cement in use worldwide. The CO2 is cooked out of limestone, resulting in calcium silicate, the constituent molecules of clinker.

      Ancient Roman cement does not seem to be primarily calcium silicate, though studies are ongoing. The manufacturing process has been lost to history, and there was quite a bit of variance in the formula over the centuries it was made.

    4. Re:Well known... by smoot123 · · Score: 1

      Well, from reading TFA, I think about half is released from the limestone and 40% is exhaust from heating the kiln. Thus, I suppose one "easy" answer is to use nuclear furnaces instead of natural gas ones. Instant 40% reduction (more or less).

      One practical issue is there are cement plants all over the place. Much as I like the concept of small modular nuclear plants, I don't see us building nearly enough of them to put one next to every limestone quarry. And I got to believe a gas-fired kiln is a lot cheaper than even the cheapest modular nuclear plan we can imagine.

      Oh, and I suppose we could try using solar energy (a mirror farm seems a reasonable approach) but that also seems wildly impractical. I dunno, an electric arc furnace powered by wind?

    5. Re:Well known... by Headw1nd · · Score: 1

      It is about 50/50. To make cement, you generally start with calcium carbonate, and decompose it into calcium oxide and CO2 at a high temperature. So CO2 is produced by both the process itself, and by the energy use required to achieve and maintain that temperature.

    6. Re:Well known... by ElizabethGreene · · Score: 1

      I can't find it now, but there was a paper that described a solar thermal plus electrolysis process as an alternative to natgas for this. The waste product was CO2 or CO2 depending on the process temperature.

      According to the now-unbingable paper it took less energy than calcining in a furnace and the CO process waste was usable as a feedstock for other processes.

  5. Remember... by Thelasko · · Score: 5, Informative

    Concrete is made with cement and aggregate. Cement is not the same as concrete. The two are not interchangeable.

    --
    One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
    1. Re:Remember... by Trailer+Trash · · Score: 1

      Concrete is made with cement and aggregate. Cement is not the same as concrete. The two are not interchangeable.

      "Cement" is also a generic term. What we're actually talking about here is "Portland Cement". Roads are typically made with "asphalt cement" and aggregate, for example, which is totally unrelated.

      --
      Do you have ESP?
    2. Re:Remember... by hey! · · Score: 1

      True, but for practical purposes irrelevant, unless you have an economically viable concrete formulation that doesn't include quicklime clinker in some way. It is impossible to reduce the carbon footprint of concrete (180 kg/mt) without either reducing the carbon footprint of Portland cement (927 kg/mt), or replacing the cement component entirely.

      There are concrete formulations that don't include Portland cement, but they're much more expensive.

      --
      Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
    3. Re:Remember... by Actually,+I+do+RTFA · · Score: 1

      I just wanted to point out that TFS, and not just the long blockquote but the sentence at the beginning, makes this exact point.

      --
      Your ad here. Ask me how!
  6. Ferrock: Stronger, More Flexible, Greener than Cc by pgmrdlm · · Score: 1

    https://buildabroad.org/2016/0...

    I thought there was a previous story here about alternates to Concrete? Just can't remember what/where they are. Not sure this is what was mentioned in the article, but.
    What are the advantages? Compared to Portland cement (made from chalk and clay and resembling Portland stone in color), which is one of the leading types in use throughout the world today, Ferrock is actually five times stronger.

    --
    Anonymous comments are as pathetic as the anonymous "sources" that contaminate gutless journalism from the New York Time
  7. Re:Ferrock: Stronger, More Flexible, Greener than by pgmrdlm · · Score: 2

    Compared to Portland cement (made from chalk and clay and resembling Portland stone in color), which is one of the leading types in use throughout the world today, Ferrock is actually five times stronger. It can withstand more compression before breaking and is far more flexible, meaning it could potentially resist the earth movements caused by seismic activity or industrial processes. One of the unique properties of Ferrock is that it becomes even stronger in salt water environments, making it ideal for marine-based construction projects. And rather than emitting large amounts of C02 as it dries, Ferrock actually absorbs and binds it! This results in a carbon-negative process that actually helps to trap greenhouse gases.
    sorry, missed some things in the previous post

    --
    Anonymous comments are as pathetic as the anonymous "sources" that contaminate gutless journalism from the New York Time
  8. So what happened to Ferrock? by SuperKendall · · Score: 2

    If you look at the URL for that story, it's from 2016...

    if you try to follow the link to ironkast.com, you just get a big "SITE UNAVAILABLE PAGE" message.

    So what happened? I remember reading about that before, it seemed like a great idea with a lot of benefits.

    It makes me wonder if there was some downside they didn't report in that article... material science is hard stuff (not even joking there. Well maybe just a little).

    --
    "There is more worth loving than we have strength to love." - Brian Jay Stanley
    1. Re:So what happened to Ferrock? by GoTeam · · Score: 1

      All is not lost. Internet archive to the rescue: https://web.archive.org/web/20...

    2. Re:So what happened to Ferrock? by pgmrdlm · · Score: 1

      Yea, I was too. I swear I had seen a previous story here about a replacement to concrete. And when I was looking for alternatives, this one seemed the best replacement. Depending on the need for concrete, there is all kinds of alternate types of materials that can be used.

      --
      Anonymous comments are as pathetic as the anonymous "sources" that contaminate gutless journalism from the New York Time
    3. Re:So what happened to Ferrock? by SuperKendall · · Score: 1

      That describes what they aspired to be though, not the apparent complete vanishing act they have performed. Is anyone still developing or using Ferrock anywhere? I can't find signs it is used anywhere in practice, in fact most of what I find related to Ferrock (even recent links) all flows back to that same article!!

      --
      "There is more worth loving than we have strength to love." - Brian Jay Stanley
    4. Re:So what happened to Ferrock? by GoTeam · · Score: 1

      Ah, gotcha. Makes sense

  9. Re:Concrete? by cascadingstylesheet · · Score: 1

    You mean like Scooby-Doo real estate developers?

    And it would have worked, too!

  10. Re:Concrete? by pgmrdlm · · Score: 1

    Hey, I bought a bridge from Scooby Doo. Fucking Velma showed up in a wet t-shirt and no bra. God damn, that woman has some big tits.

    --
    Anonymous comments are as pathetic as the anonymous "sources" that contaminate gutless journalism from the New York Time
  11. Solution by 110010001000 · · Score: 4, Funny

    Obviously the solution is to tax cement.

    1. Re:Solution by herve_masson · · Score: 1

      Obviously, we could also detax wood for individual construction for example :) I'm living in a place where most houses get built from concrete, because it's cheap. It takes a hell of energy to produce plus it "gives" mountains of CO2. That's absurd... Yes, this is a place where taxes could be efficient (though they would have to fight very powerful businesses).

    2. Re:Solution by fat_mike · · Score: 1

      Man, I have been farting all day. An average of 8 seconds per fart. There are are 7.7 billion people in the world. Let's say 35% of those people fart 8 seconds per fart. That is 2.695 billion people farting for an average of 8 seconds per fart. That is roughly a little less than 22 billion fart seconds per day. Or 366666666.667 farts per hours. The average volume of a fart is 0.264172 gallons. That equals 366666666.667 gallons of farts per hour. Talk about man made global warming. We should tax farts.

    3. Re:Solution by fat_mike · · Score: 1

      My bad, 96863066.6668 gallons of farts per hour.

  12. We should tax cities by Anonymous Coward · · Score: 1

    Cities arguably have the most concrete, so it only makes sense that they pay up the most.

  13. Timber by Luthair · · Score: 1

    Interestingly if you search there has been progress made in large scale timber construction in recent years.

  14. Re:carbon capture by Anonymous Coward · · Score: 5, Funny

    There's another problem. Global concrete production is around 4 Billion tons per year. Every year, we're adding 4 Billion tons to the weight of the earth.

    Now, the earth is very heavy -- about 6,000,000,000,000,000,000,000 tons. But still, adding 4 Billion tons every year will eventually cause problems.

  15. Easy solution by goombah99 · · Score: 1

    just turn it all into limestone and bury it in the ground. Oh wait...

    --
    Some drink at the fountain of knowledge. Others just gargle.
  16. Re:carbon capture by K.+S.+Kyosuke · · Score: 2

    Like cement, for example?

    --
    Ezekiel 23:20
  17. please fix title by schematix · · Score: 1
    this is an argument i have with my wife and 2-year old on a regular basis....

    Repeat after me: Cement is not Concrete. Concrete is Not Cement

    Concrete = Cement + Aggregate

    Cement is the glue that holds it all together to make Concrete.

    --
    Scott
    1. Re:please fix title by schematix · · Score: 1

      oops please ignore. misread the summary. OOPS.

      --
      Scott
    2. Re:please fix title by Chris+Mattern · · Score: 1

      Cement is the glue that holds it all together to make Concrete.

      In fact, "cement" is simply another word for "glue." See "rubber cement".

    3. Re:please fix title by Chris+Mattern · · Score: 1

      All this is true, but they really do mean "cement". It's the manufacture of cement that makes all the CO2. Yes, that cement is then used to make concrete, but it's the cement manufacture that's the problem, not the concrete.

  18. Plans for environmentalists by Tolvor · · Score: 1

    Environmentalists already want to humanity to exclusively eat insects and pests
    http://theconversation.com/eat...
    So take meat off the menu, and add roaches, ticks, maggots, and leaches. Yum!

    They also advocate for the reduction of 90%+ of earths population.
    https://www.conservapedia.com/...
    Think the people that remain will include you?

    Now in addition they want to take away the ability to build buildings and roads from concrete, and certainly not wood, and most definately not harmful plastics, and forget glass. Environmentalists also do not approve of iron, steel or other refined metals (harmful gases, destructive to environment when mined, energy intensive).

    Did you know that modern agriculture is a big producer of CO2 gases? Enviromentalists want this to go. No more corn, carrots or potatoes.

    This is environmentalism. These are the facts.

    1. Re:Plans for environmentalists by Spy+Handler · · Score: 1

      Environmentalists already want to humanity to exclusively eat insects and pests

      Yeah it's a stupid idea.

      They also advocate for the reduction of 90%+ of earths population. Think the people that remain will include you?

      In every nation and human culture that has ever existed that I know of, murder is illegal and highly frowned upon. So yeah, I think you (in the generic sense) will remain.

      It's very easy to reduce the population without resorting to murder. Just sterilize newborn babies. Lots of people in developed countries voluntarily undergo sterilization. Often they pay for the procedure out of their own pocket and have it done to themselves. So it's hardly a cruel or unusual practice.

      Now in addition they want to take away the ability to build buildings and roads from concrete

      Another stupid idea. All the "carbon footprint" bullshit in the world is meaningless without population control. You can drive a Prius and eat tofu and insects and live in a mud hut that you built yourself, and all that means absolutely nothing if you pop out a bunch of babies. On the other hand, a guy who drives a 4x4 gas guzzling SUV and lives in a McMansion who decides to have no children will be much better for the environment than the Prius-driving vegan with multiple babies.

  19. Re:carbon capture by bluelip · · Score: 1

    Too late, you're "that person".

    Well played, #57818994.

    --

    Yep, I never spell check.
    More incorrect spellings can be found he
  20. Re:LMGTSFY by PPH · · Score: 1

    Brazilâ(TM)s new president plans to plunder the Amazon

    Modern civilizations impact on the Amazon has been appalling. We need to go back to what it was before Europeans arrived on the continent.

    --
    Have gnu, will travel.
  21. Re: carbon capture by Anonymous Coward · · Score: 1

    I am actually interested in what percentage of concrete is wasted. I wonder how they plan ahead for such things. Do they just make an expected percentage that need to make that they will not need?

    We purchase non GMO all organic shade mined concrete and always recycle what when we can.

  22. Re:Why no one is addressing - Fart and its contrib by PPH · · Score: 1

    But if a cow is slaughtered to feed me, it stops farting. My dietary predilections are saving the planet.

    What we need to do is to get rid of all the cows that are just wandering around, farting (and belching). Hindus, I'm talking to you.

    --
    Have gnu, will travel.
  23. Re:Ferrock: Stronger, More Flexible, Greener than by technosaurus · · Score: 3, Funny

    Portland cement absorbs CO2 while setting... Just not as much as it takes to make the clinker using fossil fuels. With solar kilns it could be close to neutral

  24. Re:Don't care about harming Earth by ZombieCatInABox · · Score: 1

    So in order to cure to patient from his cancer, you're going to kill the patient ?

  25. Use Geo-polymer concrete instead by F34nor · · Score: 3, Interesting

    https://en.wikipedia.org/wiki/...

    It is what the pyramids were made from, pour-able limestone.

    1. Re:Use Geo-polymer concrete instead by TimMD909 · · Score: 1

      https://en.wikipedia.org/wiki/...

      It is what the pyramids were made from, pour-able limestone.

      Nice try, but we all know the truth.

    2. Re:Use Geo-polymer concrete instead by Anonymous Coward · · Score: 1

      Oh god that article's a raging dumpster fire of biased POV.

      I guess I shouldn't be too surprised, given that the bulk of it was written by the person (named in the article) who came up with the term "geopolymer", and who apparently has been blocked from editing Wikipedia over legal threats related to people editing his content.

  26. Re:carbon capture by hey! · · Score: 4, Insightful

    Well, there is no end to "cost is no object" solutions to greenhouse gas emissions. The problem is that in the real world, cost *is* an object, and a very important one.

    This is why cap and trade is a viable, market oriented solution to greenhouse gas emissions. Normally the 182 kg of CO2 that's emitted when I produce a ton of concrete to sell to you isn't part of our transaction. Under cap-and-trade, CO2 reduction becomes a profit center, because if I can reduce my emissions below some reasonable target (e.g. down to 150 kg), I can sell the surplus to someone who can't meet the target.

    The problem is that cap-and-trade is not politically viable, because people invested in technology that can't be upgraded are currently dumping their pollution for free.

    --
    Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
  27. Re:Ferrock: Stronger, More Flexible, Greener than by Billy+the+Mountain · · Score: 1

    Ferrock, there are several problems with it. For example, the hype says it absorbs CO2. If it absorbed significant quantities of CO2, then the structure would gain mass as it aged. How would you design something that starts out at one mass, then continually bulks up over time? Would it's dimensions bulk up as well? FeCO3 is the material. Also ,It requires iron powder, not iron oxide powder. Iron powder does not occur in nature. Instead, you must first smelt iron oxide which, you guessed it, releases CO2 into the air. Not sure about the price. David Stone, the principal, says they use recycled steel powder but suspect it would be more expensive than baking calium carbonate.

    --
    That was the turning point of my life--I went from negative zero to positive zero.
  28. They should self-regulate by SuperKendall · · Score: 2

    The main problem is that two of those "local governments" are India and China - until we figure out a way to get them in check

    Since you can't control what they do, the only way you can "get them in check" is to use improved concrete alternatives locally and show ways in which it is superior, so it would naturally be adopted over traditional means.

    China and India have also both signed onto global warming accords so it's obvious they are highly motivated to address the issue, otherwise why would they be signatories.

    --
    "There is more worth loving than we have strength to love." - Brian Jay Stanley
    1. Re:They should self-regulate by dcw3 · · Score: 1

      "Since you can't control what they do, the only way you can "get them in check" is to ..."

      There's more than one way. Economic pressure typically works the best if/when diplomacy doesn't.

      --
      Just another day in Paradise
  29. Re: carbon capture by Shotgun · · Score: 1

    This is what makes a good construction contractor, more than anything else. Being able to correctly size a job and order the right amount of materials, because mistakes are costly.

    For concrete, you have to get very close, but not under. If you are under, it should be by only a small amount, and you can make up the difference by mixing up a bag on the spot. If you go under by a lot, you'll be calling out another truck and possibly looking for another job. If you go over, by a small amount, they will just dump it at the job site or use it to fill a hole. If over by a significant amount, the truck driver usually has a side thing going where someone is trying to lay a driveway and is will to get it done piecemeal to save money.

    My best friend's father layed concrete for 40 yrs. BTW, his driveway was the ugliest piecemeal jumble of concrete sections you've ever seen.

    --
    Aah, change is good. -- Rafiki
    Yeah, but it ain't easy. -- Simba
  30. Re:Leftists by Rei · · Score: 3, Insightful

    I assume that they were talking about wood, which isn't mud. But you can most certainly can reduce the carbon footprint of concrete construction itself. My home uses a pozzolanic mix, with about half of the cement replaced by basalt dust, and most of the steel replaced by basalt fibre rebar.

    Pozzolanic concrete is slower to set, but has more long-term durability. Chemically, it harkens partially back to Roman concrete. There are lots of different pozzolans besides basalt dust, including volcanic ash, coal fly ash, activated clays, etc.

    --
    That last paragraph contained spoilers, so if you don't want spoilers go back and don't have read it.
  31. Re:carbon capture by Chas · · Score: 1

    Cap and trade is a game. Nothing more.

    It won't actually have any real-world effect.

    --


    Chas - The one, the only.
    THANK GOD!!!
  32. Graphene used to make stronger, greener concrete by DallasTruaxxx · · Score: 1

    FTA: "Additionally, the inclusion of graphene in the concrete reportedly allows for a reduction of about 50 percent of other materials used, including cement. The scientists state that this factor should result in a 446 kg/tonne reduction in emitted CO2." https://newatlas.com/graphene-...

  33. Not a problem in this case though by SuperKendall · · Score: 1

    That is the problem with CO2 and Global warming. It is a real problem, but it isn't easily seen, and to fix it requires a lot of changes

    That's the thing. In a lot of other areas CO2 reduction may require complex changes.

    But in terms of fundamental material used in construction, really not - find an alternative that is structurally sound, mandate construction use it. Done.

    I specifically wonder why California is not doing this already when they are perfectly willing to regulate many other things of greater complexity in order to reduce CO2 emission.

    This seems like an obvious quick win for CO2 reduction all over the place, so why are no alternatives for traditional concrete being actively explored and used? At this point a number of alternatives should be commercially viable.

    --
    "There is more worth loving than we have strength to love." - Brian Jay Stanley
  34. We have to have Concrete by kramer2718 · · Score: 1

    But that doesn't mean that we can't change the technology used to make it. Solidia claims to have a fix.

    --
    http://yetanotherpoliticalrant.blogspot.com
  35. Solar cement kilns are a thing. by couchslug · · Score: 1

    https://www.mineralandwastepla...

    https://en.wikipedia.org/wiki/...

    --
    "This post is an artistic work of fiction and falsehood. Only a fool would take anything posted here as fact."
  36. How much of that 8% is from energy production? by jcochran · · Score: 3, Interesting

    Because the cement itself is carbon neutral.

    Reactions
    CaCO3 ==> CaO + CO2
    CaO + H2O ==> Ca(OH)2
    Ca(OH)2 + CO2 ==> CaCO3 + H2O

    So for each molecule of cement you make, you do produce 1 molecule of carbon dioxide. Then to use the cement, you add a molecule of water. And then over time, the result reacts with carbon dioxide (removing the carbon dioxide that was released when the lime was made) and releases a molecule of water.

    The only non-neutral production of CO2 from making cement is that from whatever source of energy you use to heat up the calcium carbonate to produce the lime.

    Doing a bit of research, it looks like 60% of the carbon dioxide released is from the chemical reaction and 40% from the heat used to drive the reaction. Since the 60% from the reaction will be reabsorbed by the cement, we can ignore it. So the actual amount of CO2 due to cement production isn't the 8% the article mentions, but something closer to 3.2%.

  37. Re:carbon capture by reboot246 · · Score: 1

    Worse yet, some of those tons of concrete are being used on islands! There may be a danger if too much is used on one side of an island causing the island to tip over!

    That's according to Democrat Rep. Hank Johnson's theory about islands. You can't make this shit up. And people vote for idiots all the time.

  38. Lime mortar takes the CO2 back by aberglas · · Score: 2

    When it sets. Ca(OH)2 + CO2 -> CaCO(OH)2, back to Calcium Carbonate.

  39. We can sequester carbon in biomass, right? by fustakrakich · · Score: 2

    Shouldn't we just have more babies?

    --
    “He’s not deformed, he’s just drunk!”
  40. Right up there with cow farts! by p51d007 · · Score: 1

    Now there will be a ban on concrete to "stem man made global warming", just like there was a push to ban cows, or make them wear some sort of diaper to capture that CO2 in their farts. Ban concrete, guess we'll have to go back to building everything out of lumber. Oh no! can't do that, might cut down too many trees. Guess we'll all go back to living in caves. Nope, can't do that, might displace the animals, reptiles or insects that live there. You anti everything morons don't get it. One good volcano burps out more "nasty Co2" than anything man ever did or could do. Mt. St. Helen's alone screwed up "the weather" more than we ever have. Just smoke your mary jane, sniff up your coke and leave the rest of us alone.

  41. Carbon is reabsorbed by drwho · · Score: 2

    Carbon dioxide is released as lime is burned, to make calcium oxide, the primary component of regular cement. As the cement sets, it reabsorbs a great portion, if not all, of the CO2 originally produced. https://www.cement.org/for-concrete-books-learning/concrete-technology/concrete-design-production/concrete-as-a-carbon-sink

    Because the CO2 is produced as a point-source pollution, and absorbed in a distributed manner, cement could become carbon-negative by doing the easy point of sequestering the carbon at its source. This is best done by use of a microbial reactor, that is, the gas bubbled into water containing algae and exposed to sunlight. The algae, or its oil, can then be used as fuel. See Boyrtrococcus braunii on wikipedia.

  42. Re: carbon capture by hey! · · Score: 1

    I've heard the same arguments made against investing in the stock market: it's just legally sanctioned "gambling".

    Throwing a pejorative sounding tag on an idea isn't much of an argument.

    --
    Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
  43. Re: carbon capture by hey! · · Score: 2

    We need to reduce carbon emissions from the sources with the highest marginal reduction per cost. If only there were some way resources could be allocated to that by some kind of magical, invisible hand....

    --
    Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
  44. Re:This is horrible news! by LynnwoodRooster · · Score: 1

    This is clearly an Australian conspiracy, as they want the world to tip over so they don't have to keep hanging on to the ground to avoid falling off!

    --
    Browsing at +1 - no ACs, I ignore their posts. So refreshing!
  45. cow farts contribute more...dumases by AndrewFlagg · · Score: 1

    farmer green jeans here -- learn more @ https://bit.ly/2voEVIr

  46. Want to cut CO2? Don't buy organic by LynnwoodRooster · · Score: 1

    About 14-18% of CO2 emissions are from agriculture. And organic agriculture produces 50-70% more CO2 than modern farming techniques (that includes all considerations for fertilizer, techniques, etc). Cutting organic farming techniques (voluntary, like in the US and most of the EU, and involuntary like in most of the 3rd world) could easily significantly cut total CO2 output.

    --
    Browsing at +1 - no ACs, I ignore their posts. So refreshing!
  47. Carbonated beverages by RandySC · · Score: 1

    Ban them all -- Coke, Pepsi, fizzy water. They leak significant amounts of CO2 into the atmosphere. While you are at it, ban volcanoes, particularly in Iceland.

    --
    Organization: alphabetical, sometimes numerical or messy
  48. Title is right by Actually,+I+do+RTFA · · Score: 1

    Cement is part of concrete, and the aggregate isn't what contributes CO2. So, the cement is the cause, even if concrete is the most common use for cement.

    --
    Your ad here. Ask me how!
  49. Re: carbon capture by pslytely+psycho · · Score: 1

    Ok Woody.....

    https://www.youtube.com/watch?v=2jtPBpUdysM&ab_channel=MartinMcCary

    --
    Donald Trump, on a crusade to make Nixon look respectable
  50. Re: carbon capture by dcw3 · · Score: 1

    I am actually interested in what percentage of concrete is wasted. I wonder how they plan ahead for such things. Do they just make an expected percentage that need to make that they will not need?

    We purchase non GMO all organic shade mined concrete and always recycle what when we can.

    But is it free range organic?

    --
    Just another day in Paradise
  51. Re:carbon capture by Agripa · · Score: 2

    This is why cap and trade is a viable, market oriented solution to greenhouse gas emissions.

    Cap and trade is only a viable solution to facilitate rent seeking. If you want a solution to greenhouse gas emissions, then assign an objective negative cost and tax it without exceptions.

  52. Re: carbon capture by Agripa · · Score: 2

    We need to reduce carbon emissions from the sources with the highest marginal reduction per cost. If only there were some way resources could be allocated to that by some kind of magical, invisible hand....

    Inconceivable!