Roman concrete could literally heal itself! Researchers found a 2,000-year-old worksite in Pompeii where builders were mixing up a special blend with quicklime and volcanic ash. When water hit, it created heat and left behind tiny lime bits that could react again if cracks formed—basically, the concrete patched itself. Turns out, the Romans were way ahead of us on sustainable building tricks. Imagine if our sidewalks could do that! #History #Pompeii #RomanConcrete