Aleteia logoAleteia logoAleteia
Friday 02 June |
Saint of the Day: Sts Marcellinus and Peter
Aleteia logo
Art & Culture
separateurCreated with Sketch.

In search of the lost art of ancient Roman concrete

J-P Mauro - published on 07/14/17

Their unknown recipe makes concrete that grows stronger over time.

What can God do in your life with one Bible verse a day?
Subscribe to Aleteia's new service and bring Scripture into your morning:
Just one verse each day.
Click to bring God's word to your inbox

Concrete is an affordable material that can be poured to fit any shape and dries to be as strong as rock. Unfortunately it is very porous and sucks up water, which freezes in cold months and causes cracks. While some concrete structures can last 50-60 years, these cracks can appear within the first few years after construction and can be devastating to the integrity of a structure.

Roman concrete, however, is much longer lasting. Structures built with the ancient Roman recipe still stand today and retain their structural integrity. They have stood for 2,000 years and in all that time they’ve only grown stronger. The only problem is, the Romans’ recipe was lost long ago.

Now, The Guardian reports, scientists are closer than ever to uncovering the mystery. Analysis has revealed the ingredients include: a mix of volcanic ash, lime (calcium oxide), seawater and lumps of volcanic rock. That’s right, the seawater that has been crashing into it for two millennia was part of the hardening process:

[Marie Jackson] said this revealed another process that was also at play. Over time, seawater that seeped through the concrete dissolved the volcanic crystals and glasses, with aluminous tobermorite and phillipsite crystallising in their place. These minerals, say the authors, helped to reinforce the concrete, preventing cracks from growing, with structures becoming stronger over time as the minerals grew. By contrast, modern concrete, based on Portland cement, is not supposed to change after it hardens – meaning any reactions with the material cause damage.

Scientists are continuing to experiment with their findings, but are still uncertain as to the exact formula to recreate the ancient Roman recipe.

Support Aleteia!

Enjoying your time on Aleteia?

Articles like these are sponsored free for every Catholic through the support of generous readers just like you.

Thanks to their partnership in our mission, we reach more than 20 million unique users per month!

Help us continue to bring the Gospel to people everywhere through uplifting and transformative Catholic news, stories, spirituality, and more.

Support Aleteia with a gift today!

Daily prayer
And today we celebrate...

Entrust your prayer intentions to our network of monasteries

Top 10
See More
Get Aleteia delivered to your inbox. Subscribe here.