Hacker News Reader

I'm not an expert, but I'd be surprised if concrete is at all earthquake resistant without rebar.

Ancient Romans didn't use rebar in their concrete but they did use aggregate of different densities depending on what section of the building would be under stress. Plus if cracks form their concrete self heals due to the compounds used in it.

How many earthquakes did ancient rome suffer?

Quite a few through the centuries, with the moderate to large quakes originated from the Apennine mountains’ Mount Vettore fault about 80KM away from the city.

https://www.researchgate.net/publication/236950808_Beyond_th...

https://blogs.agu.org/geospace/2019/03/04/seemingly-dormant-...

You should be able to reinforce this while building, just like with other masonry.

Additionaly, if the structures are fairly small, and the walls are properly tied together, that may be enough.

Concrete isn't known for being very earthquake resistant. If you're building for that wood is a much better choice