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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)

#81

Post by fyfy18 »

abdullahkhalids wrote: post #74
jillesvangurp wrote: post #66

Earlier quoted context omitted.

Yes. And better than that using this at scale is going to require massively scaling up wood production (i.e. forestry). This too will help with capturing a lot of co2 in the soil. A lot of countries would end up restoring farm land to production forests and probably end up using sustainable practices for this. For those unfamiliar with CLT, this is a high tech building material suitable for making e.g. sky scrapers o…

What are the long term health effects of the chemicals used in the production of CLT, on the residents of the houses?

Some adhesives use formaldehyde, but you can also get formaldehyde free adhesives. It's no different than plywood or OSB which is greatly used in the construction of most wooden stick framed houses where that's common (i.e. North America).

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

#83

Post by nix23 »

dehrmann wrote: post #5

Meanwhile, there's a sand shortage: https://www.bbc.com/future/article/20191108-why-the-world-is... Concrete might look very different in 25-50 years.

>Concrete might look very different in 25-50 years.

True more like it looked in 150 BC:

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

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

#84

Post by aembleton »

vixen99 wrote: post #61
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.

Sorry for the tangential drift but it's ubiquitous now. I guess those boring grammar pedants should finally give up. The totally meaningless and incorrect apostrophe in it's (unless it indicates an abbreviation) has gone viral. You can even find it in headlines in newspapers. Odd really that many of us go to the trouble of adding a pointless character intent as we are on writing correct English. I think we should kee…

The English language changes over time.

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

#85

Post by opencl »

abdullahkhalids wrote: post #74
jillesvangurp wrote: post #66

Earlier quoted context omitted.

Yes. And better than that using this at scale is going to require massively scaling up wood production (i.e. forestry). This too will help with capturing a lot of co2 in the soil. A lot of countries would end up restoring farm land to production forests and probably end up using sustainable practices for this. For those unfamiliar with CLT, this is a high tech building material suitable for making e.g. sky scrapers o…

What are the long term health effects of the chemicals used in the production of CLT, on the residents of the houses?

It's the same chemicals used in the production of plywood (glue), only there's a lot less of it. It basically is plywood, just with fewer and thicker layers so a lot less glue is needed.

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

#86

Post by lotsofpulp »

notahacker wrote: post #80
jmiskovic wrote: post #70

Earlier quoted context omitted.

Do we want 100 year old buildings? I don't think we can predict the needs of building even 20 years into the future. City layout could change drastically. Monumental buildings should last a long time, but not every structure. The alternative is to build from wood whenever possible, and capture extra cabon in building material. This increases market need for wood and therefore forestation.

> Do we want 100 year old buildings? At least a fifth of the UKs housing stock is over a century old, so the answer to that question is yes, if they're built properly ...

I haven’t been impressed by any of the old UK houses I’ve been in, from rowhouses in London to detached houses in a midlands to mansion in Cotswald.

The insulation, pipes, and wiring all are quite inferior to modern standards.

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

#87

Post by lotsofpulp »

TeMPOraL wrote: post #22
thinkloop wrote: post #11

Earlier quoted context omitted.

So the biggest polluters are food, clothing and shelter - I'm seeing a pattern here...

Yes, but the question is, how much of these emissions come from the basics, and how much from extravagance?

The question is how do you define extravagance? Ask someone in a middle class suburb of the US and you will get a different answer than the most of the rest of the world.

The biggest extravagance is space. Having space (I.e. detached houses) has a knock on effect of increased emissions of everything. Increased energy usage to transport mass increased distance.

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

#88

Post by narag »

jmiskovic wrote: post #70
shortercode wrote: post #68

The largest issue with concrete is that we misuse it. As a building material it has great thermal mass ( aiding temperature stability ) and longevity. But all too often buildings are poorly designed for renovation, and hence end up being torn down after a couple of decades. A small fraction of the useful lifetime of the structure. Any building using concrete for a structure should be aiming to last at least 100 years…

Do we want 100 year old buildings? I don't think we can predict the needs of building even 20 years into the future. City layout could change drastically. Monumental buildings should last a long time, but not every structure. The alternative is to build from wood whenever possible, and capture extra cabon in building material. This increases market need for wood and therefore forestation.

Do we want 100 year old buildings?

The house where I grew up was made before Portland came to our zone, so it was made of lime mortar and rocks, some of them as big as a mellon, I found out when I tried to drill the walls to put a basketball basket.

It was demolished in the eighties, but not because it was in bad shape. I met the bulldozer operator years later and he recalled how he had a hard time with it.

I'm sure it would have been fine today, when it would be 100 y.o. or close. And I'm sure there's no other place where I'd rather live. It was cool in the summer, easy to warm in the winter, no mold, little noise from the outside.

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

#89

Post by jillesvangurp »

abdullahkhalids wrote: post #74
jillesvangurp wrote: post #66

Earlier quoted context omitted.

Yes. And better than that using this at scale is going to require massively scaling up wood production (i.e. forestry). This too will help with capturing a lot of co2 in the soil. A lot of countries would end up restoring farm land to production forests and probably end up using sustainable practices for this. For those unfamiliar with CLT, this is a high tech building material suitable for making e.g. sky scrapers o…

What are the long term health effects of the chemicals used in the production of CLT, on the residents of the houses?

According to this article: https://www.bbc.com/future/article/20190717-climate-change-w..., it's less than 1% vs 10% in things like plywood and does not use dangerous chemicals:

" Other engineered woods such as plywood and MDF are around 10% adhesive (glue), often urea-formaldehyde, which can produce hazardous chemicals during recycling or incineration. CLT, however, is below 1% adhesive, and typically uses a bio-based polyurethane. The planks are bonded together under heat and pressure to fuse that small amount of adhesive using the moisture of the wood. To look at, smell and touch, it’s as pure wood as a child’s tree house – knots and all. "

In any case, there are already quite a few buildings that use this so, I'd say this is a non-issue.

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

#90

Post by mrweasel »

jmiskovic wrote: post #70
shortercode wrote: post #68

The largest issue with concrete is that we misuse it. As a building material it has great thermal mass ( aiding temperature stability ) and longevity. But all too often buildings are poorly designed for renovation, and hence end up being torn down after a couple of decades. A small fraction of the useful lifetime of the structure. Any building using concrete for a structure should be aiming to last at least 100 years…

Do we want 100 year old buildings? I don't think we can predict the needs of building even 20 years into the future. City layout could change drastically. Monumental buildings should last a long time, but not every structure. The alternative is to build from wood whenever possible, and capture extra cabon in building material. This increases market need for wood and therefore forestation.

>Do we want 100 year old buildings?

I don't want a new house. Why? Because I refuse to live in a house with no natural ventilation. Most modern houses need air condition or at least ventilation systems, because they need to be so energy efficient, that there is no other way to get fresh air in. The fact that a house needs to be pressure tested seems insane.

Sure you can leave the windows open, but that defeats the purpose. Modern home needs to be ventilated three times a day, that means opening all the windows in the morning, when you get home in the afternoon and before going to bed. How many people will remember to do that?

The air in a modern home is often so dry that my nose start running the minute I enter. I don't want to live in that sort of climate.

Depending on the country, I think people should aim for home built from the late 1940 to mid 1970. Most likely additional isolation and new windows have been added over the years, making them reasonably energy efficient.

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