One of the best lines from Monty Python’s Life of Brian is “What did the Romans ever do for us?” The characters follow this up with a collection of marvels from sanitation and aqueducts to the road. Now it looks like the Romans are about to do something for modern civilization: Scientists have recovered the secret of Roman concrete manufacture.
That may seem a strange thing to laud, but keep in mind most Portland cement-based concrete is lucky to survive weathering and use over a half century…in Italy, there are buildings in remarkably good shape after 2000+ years. 11 harbors studied showed remarkable vigor, despite being exposed to the vagaries of wind, weather and water.
Lawrence Berkeley National Laboratories explains in this press release:
The Romans made concrete by mixing lime and volcanic rock. For underwater structures, lime and volcanic ash were mixed to form mortar, and this mortar and volcanic tuff were packed into wooden forms. The seawater instantly triggered a hot chemical reaction. The lime was hydrated—incorporating water molecules into its structure—and reacted with the ash to cement the whole mixture together.
Bigus Dickus would be proud.