Roman concrete used thousands of years ago is significantly more durable than modern concrete. One of the key differences is self-healing properties—when Roman concrete cracks, it reacts with water which quickly fills in the crack with calcium carbonate.
A recent study looked into how Roman concrete was made and tested these properties. They found that hot mixing must have been used to create quicklime instead of slaked lime. This creates more surface area within the mortar area and is the source of reactive calcium which fills in cracks over time.
- Societies live by decades, civilizations by centuries, and Roman concrete by millennia
- Roman concrete structures are still standing after 2000 years, ancient sites like the Brewarrina Fish Traps have been around for 40,000 years
- Knowing that better materials can exist that last longer might help us think more about the the Long Now and even or role in deep time