Words: Christopher Rodermond
What has been will be again, what has been done will be done again; there is nothing new under the sun. – Ecclesiastes 1:9
Merriam-Webster’s dictionary defines masonry in three basic parts: (i) something constructed of materials used by masons, (ii) the art, trade, or occupation of a mason, or
(iii) work done by a mason. Not surprisingly, the word mason was around for millenia, and the word itself is thought to have likely come from an old germanic word which means and is closely associated with the modern verb, “to make”.
The idea that the word make and masonry come from the same place linguistically makes sense. It can not be understated that at the foundations of human art, history, culture, and basic survival, masonry has been a part of our shared experience longer than agriculture or even speech. In fact, some of the earliest found tools, belonging to early hominids that predate even modern homo sapiens, demonstrate that some level of masonry has been practiced for perhaps millions of years. Even more broadly, and in a truly mind blowing level, masonry is a fundamental part of other life on earth and Nature shows us countless examples of creatures at every level of complexity, from coral to birds to many other nest building critters, exhibiting behaviors that at the broadest sense could be considered a form of masonry.
But it probably makes sense, for the purposes of this article, to consider how modern masonry began and has changed through the centuries and to see where we can gain insights and inspiration from one of the world’s oldest professions. Pipe down back there, no laughing!
An article from Encyclopedia Britannica regarding the history of masonry defines it as, “the art and craft of building and fabricating in stone, clay, brick, or concrete block. Construction of poured concrete, reinforced or unreinforced, is often also considered masonry.” This article describes the original augmentation of cave structures as the roots of masonry. From their all manner of walls, fortifications, houses, temples, tombs and monuments were built through the eons advancing to the great ancient cut stone marvels, such as the great pyramids of Egypt or the great wall of China.
It could be argued that the importance of an ancient civilization in our memory stems from whether or not there are structures of ruins which still stand that remind us of their time and former glory.
One of the most interesting and widely researched subjects regarding ancient masonry is the subject of ancient Roman concrete. According to wikipedia,
Roman concrete, also called opus caementicium, was a material used in construction in Ancient Rome. Roman concrete was based on a hydraulic-setting cement. It is durable due to its incorporation of pozzolanic ash, which prevents cracks from spreading. By the middle of the 1st century, the material was used frequently, often brick-faced, although variations in aggregate allowed different arrangements of materials. Further innovative developments in the material, called the concrete revolution, contributed to structurally complicated forms, such as the Pantheon dome, the world’s largest and oldest unreinforced concrete dome.”
An article we found at Science Alert, along with many articles from 2017, describes the research of Dr. Marie Jackson at the University of Utah, who’s research into Roman concrete appear to have solved the riddle regarding the extreme durability of the product they made and used more than two thousand years ago when she published an article regarding her research in a scientific journal in 2013:
Modern concrete is typically made with portland cement, a mixture of silica sand, limestone, clay, chalk and other ingredients melted together at blistering temperatures. In concrete, this paste binds ‘aggregate’ – chunks of rock and sand.
This aggregate has to be inert, because any unwanted chemical reaction can cause cracks in the concrete, leading to erosion and crumbling of the structures. This is why concrete doesn’t have the longevity of natural rocks. But that’s not how Roman concrete works.
Theirs was created with volcanic ash, lime and seawater, taking advantage of a chemical reaction Romans may have observed in naturally cemented volcanic ash deposits called tuff rocks.
Mixed in with the volcanic ash mortar was more volcanic rock as aggregate, which would then continue to react with the material, ultimately making Roman cement far more durable than you’d think it should be.
It should be noted that Roman concrete lacks the tensile strength of modern concrete.
Some modern purveyors of concrete are looking to get back some of the lost qualities of this ancient product with the use of fly ash integrated into a cement mix rather than using the industry standard Portland Cement, which is known to have a heavy carbon footprint. An article titled “Make Concrete Roman Again!” hosted at the online magazine Nautilus introduced us to one of the leading experts bridging the eons between ancient and modern masonry, John Ochsendorf. According to his bio, Ochsendorf is “ John Ochsendorf is a structural engineer with multi-disciplinary research interests including the history of construction, masonry mechanics, and sustainable design. Trained in structural mechanics at Cornell, Princeton, and the University of Cambridge, he conducts research on the structural safety of historic monuments and the design of more sustainable infrastructure. An expert on the mechanics and behavior of masonry structures, Ochsendorf collaborates with art historians, architects, and engineers on the study and structural assessment of historic monuments around the world. His group’s work on equilibrium methods has been extended to include early stage structural design tools for architects and engineers.
In a video on the Nautilus website Mr. Ochsendorf answers the question, What is the difference between a great ancient building a modern one, noting:
“Well, traditional buildings in stone and brick and masonry, they stand because of their geometry, and the way builders conceived them was through their geometry. When we design structures today we really rely on the strength of the materials to a huge extent. So, when we design structures of steel, or reinforced concrete, we are working the material, much, much harder. So we’re stressing it up to much closer to its safety limits. Old masonry buildings are stressed very low. So the fundamental issue is that we had knowledge accumulated over centuries or even millennia which with the Industrial Revolution was thrown out and we don’t really build like that anymore. Engineers are taught today in universities that, really, there are two dominant materials; steel and concrete. So when they come to an old structure too often we’re trying to make old structures conform to the theories that we learned for steel and concrete. Whereas, it is more useful generally to think of them as problems of stability and geometry because the stresses in these are very, very low. So, at root, the fundamental issue is that we’ve lost centuries of knowledge which has been replaced by other knowledge about how to build in steel and concrete. But today’s knowledge doesn’t necessarily map easily onto those older structures. If we try to make them conform to our theories it’s very easy to say that these older structures don’t work. It’s a curious concept for an engineer to come along to a building that has been standing for five hundred years and to say this building is not safe.”