The problem with concrete is that its usage emits a lot of CO2 and it’s not really recyclable whereas wood, as long as you plant new trees, is roughly CO2 neutral and easy to recycle.
Last I heard concrete was recycled by simply using the rubble as stones to throw into new concrete. Usually sorted by size to adhere to certain regulations or something but never without new concrete. Can you give me a source for anything else?
heard about a net-negative carbon concrete recently, havent bothered to look into to see whether they’re legit or using some carbon-credits bullshit to pretend to be net-negative.
Their website doesn’t really provide any details. Looking at some older articles (2016), it looks like MgO cement was often made with coal and the final product was not CO2 negative if looking at full lifecycle. Pratana launch in 2021, so maybe feedstocks changed.
Regardless, it seems like a somewhat new product, so adoption would be slow while confirming all performative characteristics for engineering compared to well documented Portland cement.
Yes. The trees you use to build actually store carbon while they’re still the building. However, as buildings aren’t actively taken out of the ecosystem, their carbon will eventually be set free as well, because they burn down or are left to rot or something, so these buildings aren’t net negative unless you later take care of the raw materials and take them out of the cycle. If you don’t, it’s roughly a zero sum game (roughly because your work usually emits done CO2 as well, so it’s not completely 0).
I’m reasonably sure that a timber building is probably still better than a concrete one, for the same capabilities, when total environmental impact is measured.
The problem with concrete is that its usage emits a lot of CO2 and it’s not really recyclable whereas wood, as long as you plant new trees, is roughly CO2 neutral and easy to recycle.
Concrete is extremely recyclable. Like, more than Aluminum even.
Last I heard concrete was recycled by simply using the rubble as stones to throw into new concrete. Usually sorted by size to adhere to certain regulations or something but never without new concrete. Can you give me a source for anything else?
How is that not recycling?
The issue is that you still need lots of new concrete this way. You don’t end up with a circle of your resources.
It’s not a bad idea but it isn’t climate neutral unless you come up with a climate neutral way to mix new concrete.
also iirc it requires special beach sand, which means that beaches around the world are being harvested.
Angular sand, which supply of is environmentally limited leading to black markets: https://www.scientificamerican.com/article/sand-mafias-are-plundering-the-earth/
Obligatory reminder that tree plantations aren’t equal to old-growth forest. So the latter needs to be left alone.
heard about a net-negative carbon concrete recently, havent bothered to look into to see whether they’re legit or using some carbon-credits bullshit to pretend to be net-negative.
https://partanna.com/news-hub/what-is-carbon-negative-concrete
Their website doesn’t really provide any details. Looking at some older articles (2016), it looks like MgO cement was often made with coal and the final product was not CO2 negative if looking at full lifecycle. Pratana launch in 2021, so maybe feedstocks changed.
Regardless, it seems like a somewhat new product, so adoption would be slow while confirming all performative characteristics for engineering compared to well documented Portland cement.
Burning trees is CO2 neutral because trees are part of the active carbon cycle (you’re not digging it up from deep underground to burn).
Yes. The trees you use to build actually store carbon while they’re still the building. However, as buildings aren’t actively taken out of the ecosystem, their carbon will eventually be set free as well, because they burn down or are left to rot or something, so these buildings aren’t net negative unless you later take care of the raw materials and take them out of the cycle. If you don’t, it’s roughly a zero sum game (roughly because your work usually emits done CO2 as well, so it’s not completely 0).
👍
I’m reasonably sure that a timber building is probably still better than a concrete one, for the same capabilities, when total environmental impact is measured.
Of course it is. By miles. I didn’t mean to suggest anything else.
I think we’re vigorously agreeing :-)
Where does the CO2 come from?
Mostly the cement.
Seems like it would be easy to capture, just no one makes the concrete companies do it.