Roman concrete longevity and volcanic ash chemistry

2,000-year durability of Roman concrete vs. 100–200-year modern concrete, attributed to volcanic ash chemistry. Source for student papers.

This was in the 1930s, but they probably didn't cast it until the 1910s or something. I doubt it's still around, because concrete — actually, Roman concrete lasts for thousands of years, and that's an interesting study. I've had students do papers on it. There's a lot of science behind Roman concrete and why it lasts for 2,000 years, when modern concrete typically doesn't last for more than 100 or 200 years. It has to do with a volcanic ash they used to make the concrete, and you get a certain chemistry. I don't know that much about it. So concrete will last.

Student: [Location of Edison house?]

North Mountain — in some state. You could go ask the neighbors what it's like to live in a concrete house.