Comparing Roman concrete to modern stuff really got me thinking
I was reading about the Pantheon in Rome and how their concrete has lasted almost 2000 years with no rebar. Then I look at a parking garage built in the 1980s near my house that's already cracking apart after 40 years. The difference seems to be they used volcanic ash and lime, which actually makes the material stronger over time as water seeps in. Has anyone tried mixing anything like that for a home project?