As a construction material, concrete is very popular. The reasons for its widespread use is easy to understand. It is a cost effective, durable material that is created using readily accessible materials. It’s strong under compression, fireproof and water resistant. These qualities make it a good choice for building walls and foundations because of the amount of weight that it can carry when installed and cured properly. Another advantage is that it can be molded into any shape that the architect desires. One downside is that concrete itself is only strong during compression, not tension. This can cause it to crack and break under tension if there is no steel reinforcing using rebar or welded wire. For instance, concrete alone is not strong enough for constructing columns or horizontal beams. It is, however, when used steel, rebar or wire mesh.
Another advantage of reinforced concrete is that construction elements or sections can be fabricated offsite and delivered to the construction site to be assembled. This is helpful, for instance, when building bridges. At times, buildings will be erected using precast elements with those created on site.
By using concrete with steel reinforcing, a material is created that functions well under both compression and tension. During construction, rebar is tied together to create a cage. The rebar has nodes on it which allows it to securely bond with the concrete. Typically, steel is used in rebar because it expands and contracts during changing temperatures at roughly the same rate as the surrounding concrete. This prevents cracks from developing that would allow water is seep in causing the rebar to rust. To further strengthen reinforced concrete elements, it is sometimes put through a process to prestress them. In this method, the rebar is put under tension. As the concrete is applied and begins to set, it compresses and results in a stronger product. Post-stressing is similar but tension is applied after the concrete begins to harden.
As a building material, reinforced concrete is a cost-effective material. It is no wonder why it is so popular.