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Why does it have to be either or? Aren't there plenty of use cases for the concrete with less compressive strength? Stuff like floors and walls of smaller bui

Why does it have to be either or? Aren't there plenty of use cases for the concrete with less compressive strength? Stuff like floors and walls of smaller buildings could be perfectly fine with the 25 MPa, couldn't they? Patios? Foundations of smaller buildings? If there's a good amount of stuff that doesn't need the higher compressive strengths, I'd think there could be some decent potential to offset with this stuff. Applications that really need higher strength wouldn't need to use this carbonized stuff.

lostlogin 3y ago
For some of those scenarios, couldn’t concrete be abandoned altogether? Wooden building work pretty well, though forestry has plenty of its own problems (see New Zealand and it’s series of slash disasters).
- readthenotes1 3y ago
  China, by far the largest user here, builds very tall vacant buildings with concrete. Wood can only take you so high
  - hinkley 3y ago
    With manufactured beams it can take you higher than you think, but building codes need to be adjusted.
- blackflame7000 3y ago
  [dead]
- peterashford 3y ago
  Slash is an issue of bad practices. It's fixable with better management and isn't an inherient feature of forestry
tristor 3y ago
There's need, and there's expect. Unless you expect every homeowner or other property owner to do expensive and destructive testing prior to a reconfiguration, remodel, or bringing in heavy semi-stationary loads onto their property, it's somewhat critical that concrete behave like concrete regardless of its initial use case. A simple example is in my previous home when I had a section of the master bedroom closet partially walled around a Class C TL-30 rated firesafe, and the room partially reconstructed with ballistic armor in the walls and a vault door, to turn it into a safe room for valuables + home protection. The safe had a weight of nearly 9000 pounds in a footprint of 64 by 30 inches on the floor. I was only able to do this because the house was a slab on grade construction and we knew the footing depth and slab thickness of the concrete would handle the weight. If this had been some sort of "eco concrete" it would have cracked and eventually failed under that weight, and we would not have known this because the slab thickness would have been the same. P.S.: Since everyone always asks because it's hard to find actual safes (most "safes" are garbage RSCs), it was custom built by a local safe-maker and expect to pay $$$$$. The safe I had installed was $35k, and that didn't include the room tearout/rebuild or the vault door, just the freestanding safe that went into the room.
- ryukafalz 3y ago
  > A simple example is in my previous home when I had a section of the master bedroom closet partially walled around a Class C TL-30 rated safe, and the room partially reconstructed with ballistic armor in the walls and a vault door, to turn it into a safe room for valuables + home protection. But... why? This does not seem like a typical use case.
  - marcosdumay 3y ago
    Well, it is not really atypical to have one of the thousands of possible atypical use cases in any home.
  - rcoveson 3y ago
    Why can't people just do exclusively normal things in their home, like eat corn flakes and consume popular media?
hinkley 3y ago
I don’t think it’s an accident that a lot of the carbon sink concrete companies are doing precast products. Factory conditions allow for tighter tolerances, which means you can dial in the product. Concrete poured outside has a range, and the worst case scenario is tightly controlled, but at the cost of potentially overspecced concrete. Or at least more expensive workers.
coryrc 3y ago
Then you can just use a higher share of aggregate and/or partially substitute cement with weaker but more carbon-friendly pozzolans.

lostlogin 3y ago

For some of those scenarios, couldn’t concrete be abandoned altogether? Wooden building work pretty well, though forestry has plenty of its own problems (see New Zealand and it’s series of slash disasters).

readthenotes1 3y ago
China, by far the largest user here, builds very tall vacant buildings with concrete. Wood can only take you so high
- hinkley 3y ago
  With manufactured beams it can take you higher than you think, but building codes need to be adjusted.
blackflame7000 3y ago
[dead]
peterashford 3y ago
Slash is an issue of bad practices. It's fixable with better management and isn't an inherient feature of forestry

tristor 3y ago

There's need, and there's expect. Unless you expect every homeowner or other property owner to do expensive and destructive testing prior to a reconfiguration, remodel, or bringing in heavy semi-stationary loads onto their property, it's somewhat critical that concrete behave like concrete regardless of its initial use case. A simple example is in my previous home when I had a section of the master bedroom closet partially walled around a Class C TL-30 rated firesafe, and the room partially reconstructed with ballistic armor in the walls and a vault door, to turn it into a safe room for valuables + home protection. The safe had a weight of nearly 9000 pounds in a footprint of 64 by 30 inches on the floor. I was only able to do this because the house was a slab on grade construction and we knew the footing depth and slab thickness of the concrete would handle the weight. If this had been some sort of "eco concrete" it would have cracked and eventually failed under that weight, and we would not have known this because the slab thickness would have been the same. P.S.: Since everyone always asks because it's hard to find actual safes (most "safes" are garbage RSCs), it was custom built by a local safe-maker and expect to pay $$$$$. The safe I had installed was $35k, and that didn't include the room tearout/rebuild or the vault door, just the freestanding safe that went into the room.

ryukafalz 3y ago
> A simple example is in my previous home when I had a section of the master bedroom closet partially walled around a Class C TL-30 rated safe, and the room partially reconstructed with ballistic armor in the walls and a vault door, to turn it into a safe room for valuables + home protection. But... why? This does not seem like a typical use case.
- marcosdumay 3y ago
  Well, it is not really atypical to have one of the thousands of possible atypical use cases in any home.
- rcoveson 3y ago
  Why can't people just do exclusively normal things in their home, like eat corn flakes and consume popular media?

hinkley 3y ago

I don’t think it’s an accident that a lot of the carbon sink concrete companies are doing precast products. Factory conditions allow for tighter tolerances, which means you can dial in the product. Concrete poured outside has a range, and the worst case scenario is tightly controlled, but at the cost of potentially overspecced concrete. Or at least more expensive workers.

coryrc 3y ago

Then you can just use a higher share of aggregate and/or partially substitute cement with weaker but more carbon-friendly pozzolans.