A new study believes to have found the reason behind the incredible resistance of ancient Roman concrete. Namely, it states that sea water, an element otherwise erosive and corrosive, might have helped offer the concrete its increased strength.
Ancient Roman Concrete Passed the Test of Time Thanks to Sea Water
This new study was conducted by University of Utah geologists in collaboration with Lawrence Berkeley National Laboratory researchers. These analyzed samples of ancient concrete by using advanced imaging technology. For example, they utilized microfluorescence and microdiffraction to help them observe the effects of sea water on the construction material.
They did so as previous research showed that 2,000 years old Roman concrete structures are not only still standing, but also seemingly stronger than they were a millennium ago.
Research shows that Romans made their concrete by mixing a mortar made up of lime, volcanic ash, and seawater. They also reportedly added volcanic ash to this combination, which helped strengthen and complete it.
This concrete was then used in building a variety of structures, from land-based buildings to marine structures, seawalls, and aqueducts.
The latest study took a closer look at the chemical relations occurring in this concrete. Namely, it detailed the chemical reactions generated by the addition of sea water on the minerals and their microscale structures.
It helped show that this usually corrosive water encourages the growth of interlocking minerals as it bolsters cohesive bonds.
“We’re looking at a system that’s contrary to everything one would not want in cement-based concrete. We’re looking at a system that thrives in open chemical exchange with seawater,” states Marie Jackson, a geologist part of the study.
Presently, Jackson and her colleague are trying to create a modern version based on their findings on the ancient Roman concrete. One of the difficulties in recreating this material is its volcanic rocks and ash base. Such rocks are not readily available all over the world, so a replacement will have to be either discovered or created.
Current study results are available in a paper in the journal American Mineralogist.
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