news – May 2021
Some fascinating tidbits about this most ancient of building materials.
By Douglas Weinstein
WHILE RESEARCHING THE EVOLUTION OF CONCRETE towards a more sustainable building material – concrete production accounts for 8 percent of the carbon dioxide (CO2) we pump into the atmosphere versus 2.5 percent for the aviation industry, just for one example – I’ve come across some fascinating facts and tidbits from this most ancient of building materials. I’ll save the incredible advances concrete manufacturers are making for the feature article we’ll include in the upcoming Spring issue of the magazine, and just share some cool stuff today that you might not have heard about.
Roman Pantheon and Colosseum
The Pantheon (left) is a former Roman temple, established on the site of an earlier temple commissioned by Marcus Agrippa during the reign of Augustus. Rebuilt by the emperor Hadrian circa 126 AD, the Pantheon’s large circular domed cella is the world’s largest unreinforced concrete dome. Fun fact: The ancient Roman Colosseum was also largely constructed out of concrete.
The Assyrian Jerwan Aqueduct (688 BC) made use of waterproof concrete. The aqueduct is part of the larger Atrush Canal built by the Assyrian king Sennacherib between 703 and 690 BC to water Ninevah’s extensive gardens, with water diverted from Khenis Gorge, 50 km to the north.
Mayan concrete at the ruins of Uxmal is referenced in Incidents of Travel in the Yucatán by John L. Stephens. “The roof is flat and had been covered with cement. The floors were cement, in some places hard, but, by long exposure, broken, and now crumbling under the feet. But throughout the wall was solid, and consisting of large stones imbedded in mortar, almost as hard as rock.”
Uxmal is considered one of the most important archaeological sites of Maya culture. Most of the city’s major construction took place while Uxmal was the capital of a Late Classic Maya state around 850-925 AD.
Earliest Recordings of Concrete Structures
The earliest structure I’ve come across dates back to 6,500 BC, by the Nabataea traders in regions of modern Syria and Jordan. They created concrete floors, underground cisterns and housing structures. And about 3,000 BC, a form of cement was used to build the Great Wall of China.
The techniques for producing cement have undergone many changes over the centuries and it was really Joseph Aspdin who invented what is known as Portland cement in 1824 that kick-started wide-spread use in home construction.
Part of the process in making cement entails the release of CO2 and that’s where some incredible advances are being made to either capture CO2 in the manufacturing process and/or create new materials and methodologies to reduce the carbon footprint of the ubiquitous building material. More on that in the Spring issue of Technology Designer Magazine.