Have you ever marveled at how some of the truly ancient structures (The Basilica of Constantine in Trier, Germany; Newgrange in Boyne Valley, Ireland; the Great Wall of China; the Roman Coliseum/Flavian Amphitheatre in Rome, Italy, etc..) around the world are still standing and some of our modern-day buildings or structures have crumbled (Bishopsford Road Bridge in Mitcham, London, England; Sanibel Causeway in Sanibel, Florida; New Orleans Hard Rock Hotel, New Orleans, LA; Champlain South Tower Condo, Surfside, FL)? There may be many factors as to why this occurs, but the concrete used for erecting these structures may play a part. Read on.

Roman builders used a volcanic ash and lime type of concrete that when combined with seawater became extremely resilient to time and the forces of nature. Their concrete appears to have strengthened over time, especially that which has been submerged in seawater or partially emersed in same. Geologists call this a C-A-S-H binding process. C-A-S-H stands for calcium aluminate silicate hydrate. Those elements combined with seawater and lime create zeolite and Al-tobermorite in pumice.

One commonly used concrete of today is called Portland Cement and it is a variation of a type that was used in Roman times too. Also, it is important to note that there are over one hundred varieties of concrete. I might assume that the selection of which concrete to use is dictated largely by the type of construction being done. According to https://pubs.geoscienceworld.org/msa/ammin/article/102/7/1435/353606/Phillipsite-and-Al-tobermorite-mineral-cements, there is a much longer lifetime to the Roman type of concretes
compared to what we can recreate today. Concrete mixed using the pozzolanic blends of cement is known to have less calcium hydroxide. This might extend their lives, but also add to their weight. At some point, concrete structures were erected with steel to reach higher heights or longer lengths. However, steel introduced into seawater environments or even near seawater environments only seemed to weaken over time as the steel rusted. The Roman-type cement was far more durable in this environment.

Can our modern-day building versions compete with those from bygone eras? Today we have more possibilities for construction. Technology has improved the way we build and in some instances the cost of building, but is it as durable as what was produced in the past?
Concrete is not the only method of construction now or even in our not-too-distant past. Natural disasters tend to highlight the shortfalls in our construction regardless of the components used for building. For instance, let’s look back to Hurricane Katrina which was a direct hit to New Orleans, LA in 2005 as a category five. Destruction was nearly complete for that area and cost more than 1.25 billion dollars with over 1800 deaths. According to those who saw the aftermath first-hand none of the structures that had used drywall were left standing. Only one building that had been constructed using plaster was still standing.

Hurricane Michael hit the panhandle of Florida in 2018 as a category-five storm. In the aftermath of this disaster, it was determined that there was a lot of structural weakness in some construction largely due to lax building codes. NBC News ran a story detailing how the builders in that region used the building codes to help cut corners that aided in the number of fallen structures from this powerful storm. For instance, it revealed that some builders had used particle board instead of plywood for roofing and
staples in place of roofing nails. What were they thinking?

In 2022 Hurricane Ian, a category four storm, pummeled Fort Myers, Florida, and the surrounding areas too. Storm surges and winds in excess of 150 miles per hour ripped apart homes, condominiums, hospitals, and anything else as it marched ashore The Sanibel Island bridge collapsed hindering rescue and recovery efforts. 144 people died. In the wake of the hurricane tornadoes swept through tearing up what precious little the hurricane had failed to. Again, as time moved onward, there were fingers pointing at anything and everything that was not constructed well.

How much do the materials used for construction play a part in the longevity of the structure? Concrete, wood, and steel have been used for literally centuries. The structural integrity of a building is not only dependent upon its exterior, but all things interior too that add to its ability to stand strong. Many times structures in the past were over-engineered to try to ensure safety, but that engineering came with a cost. What has changed?

There are a number of ways that concrete and other construction today is supposed to save money and promote sustainable development. Some things they are using are 3D volumetric construction, tunnel forms, flat slabs, hybrid concrete, thin joint masonry, and precast. All have benefits. Hurricane Andrew hit South Florida in 1992 as a category-five storm. It leveled much of that area. Those suffering most were also taken advantage of by avaricious builders and in some instances simply outright liars and not builders. It was perhaps the first super awful storm to highlight what was amiss with buildings and other structures. It began upping the ante for building codes and what was considered safe at least in that region of Florida. Radical changes were the responses to what was
remiss. Are they better prepared now? Probably.

Time waits for nobody. Today’s builders are trying to not only maximize the use of new technology and advancements in engineering but also attempt to please their investors by offering competitive pricing for labor and materials. Building codes have dramatically changed in order to try to create some modicum of safety for new structures and older ones alike. Over time we will see whether or not those measures have helped to keep our people safe.

Resources:
https://pubs.geoscienceworld.org/msa/ammin/article/102/7/1435/353606/Phillipsite-and-Al-
tobermorite-mineral-cements
https://www.concrete.org/topicsinconcrete.aspx

https://en.wikipedia.org/wiki/List_of_bridge_failures#2000%E2%80%93present
https://www.ferrarolaw.com/blog/2021/july/building-collapses-timeline/

https://www.nbcnews.com/news/us-news/michael-s-destruction-exposes-weaker-building-codes-
florida-s-panhandle-n920131
https://www.nhc.noaa.gov/data/tcr/AL142018_Michael.pdf
https://www.news-press.com/story/weather/hurricane/2022/12/28/hurricane-ian-ravaged-floridas-
west-coast-in-2022-everything-to-know/69759203007/
https://www.fox13news.com/weather/hurricane-ian-storm-surge-damage-fort-myers-naples-southwest-florida