#2: Roman Concrete That Outlasts Modern Mixtures
Roman concrete used volcanic ash called pozzolana, which made it far more durable, especially in saltwater, than many modern concretes. They often recycled old buildings by mixing rubble, bricks, and tiles into new concrete, showing an early form of sustainable construction. The Romans’ clever use of natural materials like tuff, gypsum, and quicklime helped their structures survive for thousands of years, even in harsh environments.
