Concrete is a heavy, rough material often used in construction. Often confused with cement, concrete contains cement, water, sand, gravel that is mixed together and spread or poured into molds. Concrete plays a major role in construction being commonly used for building foundations, floor construction, exterior surfaces and much more. However, concrete has not always been a factor in construction. So how did concrete become the staple that it is today? Like most creations, concrete went through thousands of years of change and advancement.
Concrete Before Concrete
The earliest concrete-like structures can be dated back to around 5600 BCE by an ancient civilization called the Nabatea. The territory that these people occupied had rich deposits of silica sand. They discovered that silica sand, when mixed with groundwater, created a sandy, volcanic ash material which they mixed with lime and heated to create the concrete like mixture that they used for floors and buildings.
The Ancient Egyptians used gypsum mixed with lime mortars to build the pyramids. Although mortar and concrete are different, these early advancements would eventually lead to the mixture we use today.
The Romans made further improvements to the material used in construction. While it doesn’t have much in common with the materials we use today, it was like a cemented rubble that they would lay in between stones when building. Although this concrete would be considered weak if used today, the Romans managed to build groundbreaking structures like the Pantheon, the largest unreinforced concrete dome ever built.
While having its place in early history, concrete construction lost its popularity during the middle ages after the fall of the Roman empire. However, concrete began to be used more frequently again around the 1700s when Roman scripts were found explaining the concrete forming process. It wasn’t until 1824 when a man from England named Joseph Aspdin invented Portland cement, the most common form used today. One of the reasons Portland cement has stuck around is because of its consistent process and simple recipe. Unlike natural cement which has properties that vary widely, Portland cement was manufactured by heating a mixture of limestone and clay in a kiln at around 1300°C and 1500°C. This level of concrete innovation led to several building feats such as the first concrete street in the U.S in 1891. The first concrete high rise building was constructed in 1904 in Cincinnati Ohio.
Modern Concrete Process
The process of making concrete starts with the manufacturing of Portland cement. The process has not changed much except for advancements in kilns for heating and the speed of manufacturing. Once the Portland cement is ready it is mixed with aggregates, most commonly being sand or gravel, chemical additives and any fibers and water. The concrete is then shipped to the job site by way of cement truck or pumping. You can find our articles about how cement trucks work on our blog as well!
The Future of Concrete
After all of the advancements made since ancient times, concrete has remained the same in more recent years. The mixture we have today works well and is utilized for countless projects. But one may ask, will it stay this way forever? The world today is full of innovation and with technology advancing at the pace it is, the potential for new concrete manufacturing processes could always be around the corner.