Concrete is a common building material that is widely used in the construction of many buildings and infrastructure projects. The strength, durability and flexibility of this material have added to its popularity. However, concrete has been around since ancient times – some of the oldest buildings created by humans are built from early forms of concrete. These are some of the most impressive and durable buildings built from concrete.
The Pyramids, Giza, Egypt
One of the oldest forms of concrete still in use today is in the Giza Pyramids of Egypt, built around 3,000 BC. The pyramid is made of bricks made of mud and straw, but the mortar used between the bricks is made of gypsum and lime (from heated limestone) and hardened like modern cement mortar. It hardens.
The Colosseum and Pantheon, Rome, Italy
The Roman Empire was known for its impressive architecture, many of which were built using cement and concrete very similar to those used today. To create a concrete solution, the Romans used puzzolan (a fine volcanic ash that was easily available in Italy), lime and water.
In order to build the carrying wall, they created a basic tree-chambered or brick-cracking or a combination of them that was filled with fillers or bit bricks. The shape was then filled with a puzzolan solution and wrapped to seal the concrete. The layer behind the layer of the process was repeated until the wall or stove was ready. Interestingly, in the upper layers, lighter fillings were used to reduce the weight of concrete – the Travertin was used for the fundamental layers, and the light shoe and piece were used for the upper layers.
The Colosseum and the Pantheon are both excellent examples of concrete’s longevity and adaptability. The Colosseum has concrete vaults, and a cement mortar made of limestone and clay is used between the bricks. The Colosseum was completed in AD 80 and took 10 years to build.
Meanwhile, the Pantheon in Rome has the largest unreinforced solid concrete dome in the world, measuring 43.4m in diameter. Built between 126 and 128 AD, this is an impressive record that has stood for nearly 2,000 years, especially considering that the dome did not use reinforced concrete rebar or any supports. In fact, according to David Moore’s research, the clear span of the dome was not greatly exceeded until reinforced concrete was adopted.
Eddystone Lighthouse, Cornwall, UK
Although these early concretes were used for a long time, the technique of making concrete became less popular and this method was not used again for years until the mid-18th century. British civil engineer John Smeaton conducted extensive testing of the various limes available at the time. Through his research, he discovered that the hydraulics of lime are present in limestone or related to various added minerals such as pozzolan. He combined this hydraulic lime with powdered bricks and pebbles to create the first form of modern concrete used to build the Eddystone Lighthouse in 1759 with masonry. The advantage of Smeaton’s hydraulic lime was that the mortar and concrete hardened rapidly, despite the wet conditions at the site. This early work led to the invention of modern Portland cement. Developed by Joseph Aspdin in England in 1824, it soon became the main cement used in construction.
Centennial Hall, Wroclaw, Poland
The Centennial Hall in Wrocław, Poland (then Breslau, Germany) was built in 1913 of reinforced concrete. Designed by the architect Max Berg, the hall features a reinforced concrete dome with a span of 65 metres (216 feet). Today, the hall has been designated a World Heritage site, with many visitors each year.
72 rue Charles Michels, St. Denis, France
In 1853, French industrialist François Coignet built a four-story house in Saint Denis, France. While Coignet has built unreinforced concrete houses before – many of which still stand today – the building at 72 rue Charles Michels is the world’s first reinforced concrete structure. The building is reinforced with iron rather than steel, and although currently vacant, the building has been classified as a French Historic Monument since 1998.
Lionel Allorge, CC BY-SA 3.0, via Wikimedia Commons
Alvord Lake Bridge, San Francisco, USA
This bridge was the first reinforced concrete bridge built in the US in 1889 by Ernest L. Ransom. This design uses steel reinforcing bars, survived the 1906 San Francisco earthquake and many others, and can still be found in Golden Gate Park today. Ransome invented his own rebar, which consisted of square rods of cold rolled steel. These rods are built into the bottom of the arch and are bent into the same curved profile. The Alvord Lake Bridge has a span of 29 feet (8.84 meters); however, by the 1900s, reinforced concrete bridges with spans of 100 feet (30.58 meters) or more were being built.
Pi.1415926535, CC BY-SA 3.0, via Wikimedia Commons
Court Street, Bellefontaine, USA
Along the south side of the local courthouse is America’s first and oldest concrete road. Court Street was built in Bellefontaine, Ohio in 1891 and is still in use today. Although the world’s first concrete pavement was first built in 1865 in Inverness, Scotland, and parts of this street are still in use, Court Street is notable for its great strength. Tests showed the pavement achieved an ultimate strength of 55 MPa (8,000 pounds per square inch), which is much stronger than most concretes used today.
Ben Turover, CC BY-SA 3.0, via Wikimedia Commons
The Ingalls Building, Cincinnati, USA
Built in 1903, the Ingalls Building was the world’s first high-rise reinforced concrete building. The 16-storey building is 180 feet (54 m) high, which was an engineering feat at the time. The lower strength and rigidity of concrete compared to steel meant that building structures high in concrete was challenging, especially before the development of the theory of flexible structures for reinforced concrete.
Warren LeMay from Cincinnati, OH, United States, CC0, via Wikimedia Commons
Concrete Withstands the Challenges of Time
With structures thousands of years ago, it is clear that concrete is a durable and long-lasting material, even before the invention of modern concrete. For concrete structures, does the problem not last that long? Rather, how long will it last? If these structures are any indication, the answer is: Much longer than everyone expected.
