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In this new process, it's not the cement (by its classical definition) that is cured by the CO2 in the air, it's the calcium-enriched biochar. Thus the cement p
by henearkr 3y ago
In this new process, it's not the cement (by its classical definition) that is cured by the CO2 in the air, it's the calcium-enriched biochar. Thus the cement part is still sturdy, and the biochar part avoids making it flimsy because this calcium treatment enhances its binding with the cement.
It looks like the main problem with previous experiments with biochar added in cement was that the biochar did not bind well, making a crumbling result, but this article is about solving precisely that.
- mchannon 3y agoThe article claims "[t]his calcium carbonate strengthens the biochar" but this runs counter to my understanding and I'd like to see some numbers, particularly versus alkalized biochar that is never exposed to CO2. How important is binding in compression (which is what concrete is used for)? Not very. Carbonate doesn't strengthen, it weakens. And if forming carbonate in biochar strengthens versus standard biochar, I would imagine forming oxide in biochar would strengthen even more.
- henearkr 3y agoNo, the full quote is "This calcium carbonate strengthens the biochar and helps it bind better with cement, giving strong concrete." The binding part is very important. It holds grains between them. For example that's the difference between a hard granite and a crumbly, sandy granite rock (that's called "decomposed granite"). It's day and night. And I also believe them that the treated biochar is stronger than the untreated one. Maybe if the same process was used to treat the cement itself it would be a disaster, but here that's not the case. What do you mean "forming oxide in biochar"?? The oxide of biochar is CO2. Are you trying to make fun of me heh...