The concrete mixer is an integral part of the architecture we know today, but it is also one of the key components that played a role in the longevity of historical landmarks. Concrete mixers offered a myriad of building techniques, which enabled architects and engineers to build things as grand as the Colosseum and as memorable as the Pyramids. It is quite literally the foundation that built the Statue of Liberty and allows it to still stand tall today.
These are some of the world’s greatest wonders, and their magnitude and designs are striking. Interestingly enough, the way concrete was used in the various eras of these historical landmarks is still employed in the methods and forms of concrete mixers we use today. The fascinating journey of concrete’s influence on architectural design will be unpacked in this article.
We’ll take a deep dive into the history and methods used to build and design monuments that last for centuries, and how we built upon the lessons and techniques of these forerunners in construction.
The History Of Concrete
Although the history of concrete may seem like an uninteresting topic, it is far from it. Concrete has an interesting chronicle, starting with its ingredients; the mixing of lime, seawater and volcanic ash. The Roman Empire is associated with the inventors of this concrete mixer, but they weren’t the first to create a concrete mixer. The first evidence of concrete’s precursor, mortar, was first mentioned at the Mehrgarh of Balochistan in what is known as modern-day Pakistan.
The first mixture of mortar was created by mixing mud or clay and straw, because of their accessibility and low cost. The ancient Egyptians then built upon this mixture by adding gypsum as a lubricant for large stones and eventually started using limestone as it would harden with age. That’s what led us to the Romans’ mixture of lime and volcanic ash, known as pozzolan. Pozzolan and lime mortar became common practice in Rome up until the 19th Century, which then turned into Portland cement mixture, the cement we know and use to this day.
The Invention Of Concrete Mixer
Not only is the ingredient’s progression interesting, but the way cement is used in modern concrete mixture is a technological wonder. A typical concrete mixer uses a revolving drum to mix cement and aggregates such as crushed gravel, stone and sand. The first portable concrete mixer was patented by Richard Bodlaender, a German inventor, in 1904. This version of the concrete mixer was horse-drawn, with the front wheels replaced by a drum containing paddles to churn the concrete whilst the horse pulled the cart.
However, this method was slow due to the weight of the machine – causing the horse to carry too heavy a load. The first motorised concrete mixer was created by Stephen Stepanian, an Armenian-American inventor, as a better alternative. Stepanian’s invention is seen as the predecessor to Gebhardt Jaeger, a German-Columbian, and his invention of the industrialised concrete mixer. In 1928 this was patented as a truck mixer, much like the ones you see on construction sites today.
These technological advancements have made concrete the most man-made material on the planet, with six billion cubic metres being made each year. Additionally, there is more than 2 billion tons of concrete produced every year. We have the ancient Romans, Egyptians and Middle Easterners to thank, as they laid the foundations for our architectural structures.
The Colosseum And The Pantheon
Ancient Rome’s constructions with mortar, concrete’s prototype, have produced some of the most historically notable structures. By 200 BC Romans were successfully building with mortar and concrete, with 95% of their architecture consisting of limestone mortar. The Colosseum in ancient Rome is one of these infamous lasting structures created with these mixtures. The architects combined stone and concrete to build the Colosseum’s arches to increase its strength.
Additionally, every underground passage was lined with heavy concrete blocks. The upper section used lighter concrete in addition to bricks and wood. No aspect or corner of the Colosseum’s engineering was not influenced by concrete. The materials enabled the colosseums to be built not only with durability but also aesthetically. The Romans were able to shape arches, vaults and domes through the use of their concrete mixture.
Romans did not only build the Colosseum with these materials, but also the Pantheon which is still the world’s largest unreinforced concrete dome. It consists of 16 large and structurally sound concrete pillars, with a chamber between them. The Pantheon is an anomaly, surviving earthquakes and centuries worth of weathering, but the structure’s pillars are still intact with no signs of falling. The fact that the Pantheon is made entirely of concrete with no steel reinforcement makes the dome a 2000-year-old marvel.
The Pyramids
The Ancient Egyptians used to mix mud and straw to form brick and included gypsum and lime mortars in the building of the pyramids. One of the pyramids in Giza, known as the Great Pyramid used 500,000 tons of mortar in its construction. Almost 90% of all the pyramids combined would have consisted of limestone. Their equivalent of the aggregates we know today, was geopolymer, a kind of clay called kaolinite, a fine silica and sodium carbonate.
Their unique casting is also what makes the Pyramids a marvel. The Egyptians would leave their materials for days or weeks at room temperature to turn the mixture into a rock-hard material that created a binder for limestone together into cast blocks. This is far from the modern-day Portland cement, but it is a phenomenal predecessor and innovator for concrete creations.
The Statue Of Liberty
The Statue of Liberty, although located in New York, was created in France and shipped piece by piece to the American harbour. It is an 83-precast concrete gift from France to America as a symbol of freedom. Each precast piece sits on a foundation of concrete grade beams installed into the foundations and piles of earth. Lower girders were also embedded into the walls of the Statue’s pedestal’s concrete, as this protected the statue against overturning forces as a result of the wind.
The monument has survived hurricanes and flooding for more than 100 years. Precast concrete became an innovative part of design and construction due to its durability, logistics, sustainability and resilience, being able to not only travel across the Pacific – but not falter and fall decades after its construction. The museum that was built to honour the statue uses the same materials and emphasises precast concrete in its own architectural design. The Statue of Liberty is another example of how concrete history inspired modern-day building designs.
Empire State Building
The Empire State Building’s construction in 1930 is unique in its era. The walls are made of thick, solid, composite masonry. Masonry is a type of mortar plastering, and the Empire State Building is bound by masonry bricks. These materials were ideal due to their strength, but also their concrete fireproof nature. Additionally, every column in the Empire State Building is made with cinder concrete and is encased in steel, also making the building more fireproof. In total, 62,000 cubic yards of concrete and 57,000 tons of steel columns were used in the skyscraper construction.
This was an impressive feat in engineering and inspired the rest of America’s architecture for years to come, with the Bank of America’s tower being cast and designed in the same way as the Empire State Building. The Empire State Building is a perfect example of how concrete has shaped a city and has the ability to create phenomenal lasting, yet beautiful, architecture.
Hoover Dam
The Hoover Dam is another feat of engineering. The dam is a concrete arch-gravity-type, on the border between Arizona and Nevada. It took 5 years to build, with 160,000 cubic yards of concrete being placed per month. By the end of the building process, 87.5 million cubic feet were used to construct the Hoover Dam. This is the equivalent of a four-foot-wide sidewalk that wraps along the equator of the earth. In 1936, at the time, the Hoover Dam was the largest structure to be built. They fitted steel pipes to allow the concrete to harden and cool in order to accelerate the building process. This was an innovative way to use concrete, as they could fill blocks with grout and add new layers on top of the hardened concrete to create what the structure is today.
Three Gorges Dam
Another monumental innovation in historical architectural design is the Three Gorges Dam. The project had 40 years worth of planning, surveying, researching, designing, and testing. Three Gorges Dam is located on China’s Yangtze River. It took 17 years to build and is one of the world’s largest concrete structures. It used a whopping 21 million cubic yards of concrete in its construction, using 10 times more concrete than the Hoover Dam.
The construction was unique with its use of a concrete mixer, as they had to cool aggregates, sand and other materials because high temperatures could cause problems and cracks in the concrete. Three Gorges Dam is a great example of the innovation that can be created with a concrete mixer, as the dam is able to control floods, generate power and create a more economic and environmental supplementary water migration. Concrete has played a role in changing the lives of millions in China through the architecture of the Three Gorges Dam.
In Conclusion
The concrete mixer is universally a marvel in historical architecture that has had an enormous impact on the way we design and engineer buildings today. We have learnt from the ancient Romans and Egyptians and progressed from the Middle East and Asia’s immeasurable impact. This allowed the West to benefit and create its own innovative buildings, skyscrapers and dams.
Concrete mixers have come a long way and can undoubtedly be a durable, reliable and sustainable building material. BS Power is a reliable provider of equipment that allows you to use concrete mixers in an easy and accessible way for your construction needs. We are specialists who can help you find the right concrete mixer for all your construction projects. As knowledgeable professionals in the field – we believe in our ability to help you create your own buildings and homes.