Back to future with Roman architectural concrete

Eurekalert! ^ | December 15, 2014 | Lynn Yarris

[SunkenCiv]

No visit to Rome is complete without a visit to the Pantheon, Trajan's Markets, the Colosseum, or the other spectacular examples of ancient Roman concrete monuments that have stood the test of time and the elements for nearly two thousand years...

Working at ALS beamline 12.3.2, a superconducting bending magnet X-ray micro-diffraction beamline, the research team studied a reproduction of Roman volcanic ash-lime mortar that had been previously subjected to fracture testing experiments at Cornell University. In the concrete walls of Trajan's Markets, constructed around 110 CE, this mortar binds cobble-sized fragments of tuff and brick. Through observing the mineralogical changes that took place in the curing of the mortar over a period of 180 days and comparing the results to 1,900 year old samples of the original, the team discovered that a crystalline binding hydrate prevents microcracks from propagating.

"The mortar resists microcracking through in situ crystallization of platy strätlingite, a durable calcium-alumino-silicate mineral that reinforces interfacial zones and the cementitious matrix," says Marie Jackson, a faculty scientist with the University of California (UC) Berkeley's Department of Civil and Environmental Engineering who led this study. "The dense intergrowths of the platy crystals obstruct crack propagation and preserve cohesion at the micron scale, which in turn enables the concrete to maintain its chemical resilience and structural integrity in a seismically active environment at the millennial scale."

The mortars that bind the concrete composites used to construct the structures of Imperial Rome are of keen scientific interest not just because of their unmatched resilience and durability, but also for the environmental advantages they offer. Most modern concretes are bound by limestone-based Portland cement.

[PGalt]

Interesting. Thanks for posting.

Have you seen this?…

http://www.amren.com/news/2014/12/cemetery-with-one-million-mummies-unearthed-in-egypt/#.VJRZvlMK2CE.facebook

(h/t rense.com)

[ApplegateRanch]

...and quintupled (at least) in price.

[SunkenCiv]

Now that I know what I can get paid, I’ll never work again! ;’)

[afraidfortherepublic]

I imagine that a lot of volcanic ash is available in Washington State (Mt. St. Helens). I know that they make very pretty art glass there from some of the minerals that were spewed about during the 1980s eruption when the top of the mountain blew off.

I was watching a program on either the Smithsonian Channel or one of the History channels the other week, and they stated, during a discussion of Roman concrete, that one of the ingredients in their underwater concrete was a fairly large quantity of animal blood. I’m not sure how it works, but it was supposed to allow the concrete to harden under water. They built a harbor at Cesarea with it. I asked my son, who has a PhD in Materials Engineering, and he didn’t know what properties blood would bring to the mix.

[Bigg Red]

Truly amazing.