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Cement is the source of 8% of the world's CO2 emissions (2018)

bbc.com

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Re: Cement is the source of 8% of the world's CO2 emissions (2018)

#151

Post by barumi »

stjohnswarts wrote: post #146
barumi wrote: post #119

Earlier quoted context omitted.

> Any building using concrete for a structure should be aiming to last at least 100 years. I don't know which country you have in mind but in Europe the construction industry by law is obligated to design concrete structures for residential buildings that ensures a useful life of at least 50 years, and by definition that means that the building structure shall not require maintenance for at least 50 years. Moreover,…

Maybe in Europe, but in the United States if you want to tear down a building and build another one, there is about a 99% chance you can do that and get the paperwork for it without too many hurdles other than NIMBYs.

That's an entirely unrelated issue, and fits the case of urban renewal projects whose preexisting building is not able to accommodate new functional requirements, at least in a cost-effective way.

The only factor that the use of concrete plays in this scenario is that concrete structures are expensive and time-consuming to demolish. If the investment makes financial sense then the choice of building material doesn't make any difference.

Re: Cement is the source of 8% of the world's CO2 emissions (2018)

#152

Post by [deleted] »

teruakohatu wrote: post #67
hinkley wrote: post #32

I was looking for brick pavers recently and was having quite a time locating actual bricks instead of cement pavers colored badly and textured worse to look vaguely like bricks to nobody sober during daylight hours. I can only assume their target audience is a drunken man, at night, in a rainstorm. I have to wonder why we are still looking for new ways to employ Portland cement at this point, over alternatives. You c…

> I was looking for brick pavers recently and was having quite a time locating actual bricks I am not an American but I am not sure I have even seen a paver made from brick now that I think about it. I suspect the larger a brick is, the more chance of cracking. So if it makes you feel any better, you probably would not find one in New Zealand either.

[deleted]

Re: Cement is the source of 8% of the world's CO2 emissions (2018)

#153

Post by hinkley »

teruakohatu wrote: post #67
hinkley wrote: post #32

I was looking for brick pavers recently and was having quite a time locating actual bricks instead of cement pavers colored badly and textured worse to look vaguely like bricks to nobody sober during daylight hours. I can only assume their target audience is a drunken man, at night, in a rainstorm. I have to wonder why we are still looking for new ways to employ Portland cement at this point, over alternatives. You c…

> I was looking for brick pavers recently and was having quite a time locating actual bricks I am not an American but I am not sure I have even seen a paver made from brick now that I think about it. I suspect the larger a brick is, the more chance of cracking. So if it makes you feel any better, you probably would not find one in New Zealand either.

Seems clay pavers are still out there. Here's some in NZ:

https://www.horizoninternational.co.nz/domestic-pavers/nubri...

But I don't think any national chains carry them anymore.

Re: Cement is the source of 8% of the world's CO2 emissions (2018)

#154

Post by frank2 »

magicalhippo wrote: post #139
frank2 wrote: post #136

Earlier quoted context omitted.

The wikipedia page you link to says it has a concrete core.

I think you misread? The concrete core is in reference to a building in Austria. "As the main vertical/lateral structural elements and the floor spanning systems of Mjøstårnet are constructed from timber, the building is considered an all-timber structure."

I misread. I appreciate the correction.

Re: Cement is the source of 8% of the world's CO2 emissions (2018)

#155

Post by lostlogin »

nom wrote: post #148
stjohnswarts wrote: post #147

Earlier quoted context omitted.

I think that Europeans just are biased against wood frame houses. I've heard this argument over and but a wood frame house can easily last 100+ years with maintenance and owners who care about what happens to it.

OP here. I guess you are right about the bias. I've learned a lot from this thread, thank you!

The funny thing is that Europe some really old wooden buildings. There is a 1200 year old one in Essex.

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

Re: Cement is the source of 8% of the world's CO2 emissions (2018)

#156

Post by curryst »

onion2k wrote: post #48
akira2501 wrote: post #12

Earlier quoted context omitted.

That was my biggest take away from the Biosphere documentary, as it was the concrete used in it's construction that eventually led to the abundance of CO2 and lack of O2 in that closed system. We'll clearly have to use something else for building moon bases.

Why would a moonbase need to be a closed system? What would stop it scrubbing the CO2 and venting it in to space?

Does the vacuum of space generally require a closed system? And venting the CO2 is bad for the same reason that the heat death of the universe is bad; at some point you have converted all of the usable stuff into useless stuff and have vented it somewhere that you will be unlikely or impossible to be able to recover it.

If we do that, we will have to resupply the O2 in some way other than converting CO2 back to oxygen. Either shipping new gas to the moonbase, or having the moonbase convert organic material on the moon to O2 (which sounds a lot more expensive and difficult than having plants scrub CO2 into O2 for us).

This is also not to mention the other valuable things were venting with the CO2 (heat for one; I assume keeping a moonbase at a livable temperature would be a struggle). Your scrubber also has to be able to replenish the gas while it's venting, or you risk having rapidly fluctuating pressures in the moonbase. Which is going to be uncomfortable for living things, and will require whatever the moonbase is made out of to be able to handle those changes in pressure (again, I imagine having pressure that fluctuates like a bounce house with a group of sugared up children in it is less than ideal). It's not hard to imagine a non-rigid structure like the base from The Martian bouncing off the surface of the moon when it rapidly constricts from venting CO2 and then rapidly inflates as the O2 replenisher kicks on. It would become a massive bouncy ball in 0G.

Re: Cement is the source of 8% of the world's CO2 emissions (2018)

#157

Post by swiley »

straw11 wrote: post #33
swiley wrote: post #19

Would living in tents reduce CO2 emissions? Is that preferable?

Wood, Straw Bale, Earth. This all works even in high rise building.

I live in a high rise building made out of concrete and know plenty of people who live in wood buildings. I'll pay double to not have to deal with the problems wood buildings have.

Re: Cement is the source of 8% of the world's CO2 emissions (2018)

#158

Post by takeda »

takeda wrote: post #63
throwaway698 wrote: post #52

Earlier quoted context omitted.

About meat specifically -- one has to be careful when counting all greenhouse gases versus just CO2, and pure quantity of gas vs. effect on global warming. Cattle produces a lot of methane, which has a very powerful greenhouse effect, a lot more powerful than CO2. So while it does not contribute to CO2 emissions that much, it contributes to the greenhouse effect proportionally a lot more.

Oh yeah, I remeber also driving once next to a large farm with cows, it's crazy how much of the gas they produce.

got some downvotes, but I guess those people never experienced, you can close air circulation in your car and still smell it, it's that bad.
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