Could carbon capture concrete be used for foundations and eventually replace traditional concrete?
Since concrete is responsible for 8% of total global carbon emissions, it seems essential to come up with low to no carbon emitting alternatives. PT foundations seem like a recipe for disaster in my opinion, especially if the building has a basement. I’ve done floating floors where there is no concrete slab, just crushed gravel, insulation, and wood subfloor, and then finished floor but there is still concrete for the walls on the perimeter, of course.
My understanding is that carbon capture (carbonated) concrete that sequesters carbon from C02 in the atmosphere is not used for structural purposes like foundations because it has a lower PH than portland cement, which makes steel rebar corrode faster. But it seems like this problem could be easily mitigated by using fiberglass rebar or epoxy coated steel rebar. I don’t know a lot of about this but I wonder why this technology hasn’t become more widespread. Is it akin to the slow growth of renewable sources of energy in this country caused by the state’s unwillingness to invest in the infrastructure and pressure and misinformation from lucrative polluting industries?
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Money.
...or more accurately profit in small margin industries prevent these solutions from being widely adopted without government intervention, which in our society is a whole other can of worms.
That's what I figured it came down to. It's such a senseless source of pollution if we have an alternative. Has anyone had experience using carbonated concrete for a foundation?
I'd say a better example is low-GWP spray foam. It used to not be available. A couple of states passed laws requiring its use. Then a few more. Now it's as readily available as high-GWP foam and only slightly more expensive.
The answer is yes, but not all the technical hurdles are worked out.
https://www.volts.wtf/p/taking-carbon-out-of-the-air-and is a great listen.
There is a very economical (read, profitable) technology to inject CO2 into a concrete plant, creating desirable features in the concrete and storing the CO2.
There are some techs for removing carbon from the air. These are much more experimental and the economics are more of an open ended question. I believe the tech mentioned in the podcast uses limestone where the CO2 was baked out of it once, then left to weather and grab CO2 from the air, then baked again. I'm doubtful of the economics.
Then you have various startups working on cement that doesn't have process emissions. Brimstone comes to mind, they were on an FHB podcast. Brimstone recently received certification as OPC, ordinary portland cement. That makes it much, much easier to adopt because there's no change in the rest of the concrete. The cement is chemically identical.
The other option for cement is we capture the CO2 and sequester it. Everyone will say, "but that's too expensive," but the economics are little more complicated than that.