How lime clasts heal cracks (and why it’s not magic)

20:32>> There's going to be water that goes in >> Mhm. >> into this concrete. If it's normal concrete, that water is going to push out more and push out more and degrade the whole thing. But if you have chunks of lime, calcium oxide, right, that's going to dissolve into the concrete and fill, sorry, dissolve with the water and fill the crack >> and become a kind of putty >> that like seals that crack. >> Yeah. >> Over time, >> it's a it's like an extended release. >> Exactly. So, you have these like pellets You have these pellets of like glue that get activated. >> Right. Only when >> only when there's a crack and the water goes in and then it seals that crack. That's so what's so amazing about that is,

21:14you know, they clearly had intuited that. >> That's insane. >> And what could be perceived as imperfection. >> Mhm. >> Initially actually had these uh unintended, you know, you consequences that actually made the underlying structure more robust. And just like the the open-mindedness to think about stuff and try things Yeah. to get to that cuz in this day and age we like oh no it's not the mixture is >> and and that and that's what we assumed for the longest time we assumed that like this Roman mixture was just like not good >> good >> you know but no there it might have been by design >> right >> that they did this and and it's it's

21:57dude it's it's so insane and this this actually makes sense right because Roman inspired concrete this could be a huge thing for us environmentally because Roman inspired concrete this is the Pantheon again, it's lasted for thousands of years. So even though in the process of creating this concrete, it might use more CO2 than let's say the more environmentally friendly concrete, the biggest carbon footprint when building something or the biggest carbon footprint of a building is the process of building it. >> Mhm. >> Not the materials themselves. >> That makes Yeah. If you build it once and it lasts for 2,000 years, >> that building is the greenest building

22:40>> on the [snorts] planet. Like I I would argue that the Pantheon, which is still in use, >> is like the most environmentally friendly building because it was built once and then it's been used for 2,000 years. >> Right. Right. >> Right. >> Yeah. Yeah. Yeah. Yeah. It it it's it's really hard to because also the scale of it, right? And I mean it rained for 3 days here. >> Mhm. >> And everything's falling apart. >> Oh my gosh. Yeah. [laughter] Yeah. Yeah. Yeah. Yeah. It was and and there's potholes everywhere. It's just it's just the worst. Right. So it would be really cool if we could actually rep start replicating this ancient technology and then and then start using it. And so,

23:21um, Admirich, who's the who's the lead author of this study, he actually does have a startup called DMAT