The conversation that made me rethink how I look at Roman concrete

I was talking to a retired civil engineer at the local hardware store last week. He was picking up some Portland cement and we just got to chatting about old building methods. He told me about how Roman concrete actually gets stronger over time when exposed to seawater, something about the chemical reaction with volcanic ash. I always thought of ancient builders as primitive, but here we are with modern concrete that crumbles after 50 years. He showed me a study on his phone about how their mix design is still not fully understood. It really made me feel like we've lost some practical knowledge along the way. Has anyone else had a conversation that completely flipped your view on an old technique?

3 comments

3 Comments

ivan7743d ago

My concrete barely lasts my mortgage, so yeah, they definitely had something figured out.

jakeb813d ago

Survivorship bias is real, but we also changed how we make concrete over the decades. They used more fly ash and different aggregate blends that actually bonded better with the cement paste. Modern stuff is optimized for quick setting and low cost, not for lasting fifty years.

jamie8043d ago

Question how often you actually see that concrete though. I've got a buddy who builds driveways and says most of the "it'll last forever" talk is just marketing hype. Stuff cracks within a few years if the ground settles or you get a bad freeze-thaw cycle. Not saying old concrete wasn't better in some ways, but survivorship bias is real, you know?