Driven by the need to produce stiffer and more durable resources for construction, humans have been turning to composites materials since ancient times. Reliable construction materials where needed for erecting walls for protection, for the laying of strong foundations for residential complexes, for transporting water long distances, and many other vital construction projects that have brought human civilization to what it is today. Clearly, without composite materials, we would be much less technologically advanced and our lives would be much different altogether.
About 10,000 years ago, man started engineering walls made up of mud and straw. These were essentially long slabs of mud and water mixed with the only readily available fiber at the time- straw. The slabs were dried in the sun and the end result would be blocks of hardened earth that could be stacked upon each other to form walls. Over time, the massive slabs reduced in size until they reached the standard sized bricks that we are accustomed to today.
These types of bricks were even strong enough to build housing units several stories high as seen in the medieval city of Shibam located in Yemen. This “skyscraper” walled city is often referred as the “Manhattan of the Dessert” as it boasts over 500 buildings that reach up to 11 stories in height. The city still maintains a population of about 7,000 residents to this day.
Sun dried bricks could only take mankind so far in regards to construction. Natural phenomenon such as earthquakes and floods could easily decimate entire cities composed of these types of bricks. They also required regular maintenance to repair cracks and chips in the bricks themselves. A new alternative to these bricks was needed and it came in the form of cement.
Cement is essentially a material that binds other composite materials together when hardened. Cement hardened so well in fact, that it is still widely used as a basic construction material today. The origin of cement traces all the way back to ancient times in which the Babylonians, Egyptians, and Assyrians used different materials such as mortar, sand, burnt brick, and gypsum to create a material that was much more superior than its mud brick counterpart. However, it wasn’t until Roman engineers stepped in and perfected ancient cement which would eventually be used in massive building projects like the Pantheon and the Baths of Caracalla, both of which are standing strong to this day.
Roman engineers found that if they started out with locally quarried limestone and heated in in a kiln until it becomes red hot, it ended up losing a lot of weight and it became what is called quicklime. This would be crushed and water would be added to the fire-treated rock. The new paste like substance called “slick-lime” would be mixed with sand and this would form mortar. In the past, this mortar would then be mixed with flint or other rocks, but the Romans found a substance that would turn cement into a fast-drying material that would not only set by itself, but it would also work underwater. That substance was volcanic ash. The newly discovered process would prove to be extremely effective for building everything from roads, to the aqueducts, to giant monuments to the Gods.
Aside from the heavy-duty materials such as brick and concrete used throughout history, other types of composite materials were used in various construction projects as well.
Plywood dates all the way back to 3400 BC in ancient Mesopotamia. This primitive form of plywood was created by gluing pieces of wood at different angles together which proved to be more durable than natural wood alone. Other plants like bamboo, palms, and woody plants all contain natural composites that were widely used as scaffolding and for other construction purposes.
We owe a great deal of gratitude to ancient engineers that discovered, invented, and perfected composite materials used for construction. Everywhere you look today, composites play an absolute vital role in every major construction project going on around us. In more modern times, composites have evolved into lighter, stronger, and more useful materials than ever before. In fact, the next big breakthrough for composite construction materials just might be around the next corner.