The evolution of concrete is a long and interesting story. Before the modern age, concrete was used for just about everything. It was used for floors, walls, slabs, foundations, dams, bridges, fireplaces, garages, and so on. In addition, it was also used in a wide variety of ways including being the main material used for masonry projects. From the looks of the material itself, one could instantly realize that concrete had some great strength and durability.
The evolution of concrete began when it was still being used for earthworks and as the primary material for masonry projects. As the use of concrete expanded across the Atlantic and into Central America, it became more durable and impervious to most types of environmental threats. Modern technology has played a large role in reinforcing the material. Some of the materials that were resistant to weather were replaced with polystyrene, aluminum, and polyurethane foam or polyisocyanurate.
The first few decades of concrete evolution were powered by the combination of steel reinforcement and additives that increasing the strength of the material. The first additives to concrete included iron, sulfur, and manganese-all designed to increase the strength and hardness of the material. These additives would often be mixed into the reinforcement or block form to help fortify the structure from within. While this approach worked well, the additive or blocks tend to break down over time and require repair.
A new approach that was tried for the evolution of concrete was the incorporation of polyethylene fibers into the concrete mix. The fibers are laid down as an add-on after the strengthening agents are mixed into the mix. By creating a surface with a fine grain structure, the top reinforcement occurs. This surface has increased strength and is far less subject to breaking, cracking, or shrinking. The added strength makes up for the reduction in natural beauty and sturdiness caused by the presence of polyethylene fibers.
Another important evolution of concrete that took place during the early years was the introduction of calcium for the reinforcement of concrete. Calcium chloride is mixed into the mixture as a means of lowering the amount of chloride needed to strengthen the mix. By lowering the amount of calcium in the mix, it is easier for the concrete to be formed quickly and with greater strength. Unfortunately, the calcium also reduced the aesthetic beauty of the finished product as it corrodes more easily. As a result, the use of calcium for the reinforcement of concrete was discontinued.
In addition to calcium for the reinforcement of concrete, it was discovered that adding aluminum to cement could produce stronger and tougher particles that were resistant to corrosion. The aluminum contained halide crystals that had been introduced to the cement mixture through an electric arc. The crystals formed when heated with an electrical current, which cooled the cement to below freezing point. The crystals provided a smooth surface for the year to be applied to, which was essential in ensuring that the bars would have a consistent and quality finish.
A number of different alloys were used to strengthen the concrete. Prior to World War II, steel became one of the most commonly used reinforcement substances. The steel used in the concrete mixture not only provided superior strength and tensile strength, but also was fire resistant and could be made stiff enough to withstand the stresses of bombardment. The introduction of aluminum as a second reinforcement substance provided a third option for strengthening concrete.
Although steel and aluminum alloys provide an alternative method for strengthening the concrete, they still relied on one fundamental concept. All three forms of reinforcements must be combined together in order to produce a final strength that will withstand any type of pressure or weathering that may occur. Once this is done, the builder should expect the concrete to withstand any stress that may occur over its lifetime, including natural wear and tear, years of repeated use, and even the ultimate failure. By properly combining all three forms of reinforcing steel with the right type of alloy, the result is a building that can withstand anything that Mother Nature throws at it and still remains structurally sound and intact for centuries.