The Science Life Chemistry

These chemists cracked the code to long-lasting Roman concrete

Calcium-rich rocks embedded in the material can heal cracks, experiments show

The Pantheon in Rome still stands including its soaring dome.

Built from concrete around 126 A.D., the Pantheon in Rome still stands, including its soaring dome (shown).

Stephen Knowles Photography/Moment/Getty Images Plus

By Carolyn Gramling

MIT chemist Admir Masic really hoped his experiment wouldn’t explode.

Masic and his colleagues were trying to re-create an ancient Roman technique for making concrete, a mix of cement, gravel, sand and water. The researchers suspected that the key was a process called “hot mixing,” in which dry granules of calcium oxide, also called quicklime, are mixed with volcanic ash to make the cement.