The concrete used by the Romans 2,000 years ago turned out to be capable of self-sealing small cracks. The secret lies in quicklime and hot mixing of the ingredients. According to researchers, this technology could increase the lifespan of buildings by 50%.
In ancient concrete, scientists found tiny white inclusions that had previously been dismissed as a sign of careless production. It turned out that they act as a built-in repair system: when water enters a crack, it triggers a reaction that causes calcium carbonate to fill the damage. An experiment confirmed the mechanism: after two weeks, the cracks were completely closed.
The ancient technology may get a new life. More durable concrete means fewer repairs and less cement, whose production is responsible for about 8% of global greenhouse gas emissions. It seems the Romans left us not only magnificent ruins, but also an engineering clue for the future.
