A reinforced beam is typically a concrete beam that is reinforced by steel and supports large weight loads on a vertical scale. These are generally used in large buildings for longitudinal support. They add stability to a structure and are used in areas, like floors and ceilings, to withstand large amounts of stress.
These beams are commonly used to add extra support to buildings located within an earthquake zone. They transfer the weight they bear to nearby support columns, which also act to support and strengthen the building. For example, many structures throughout China are constructed using reinforced beams due to the country’s frequent earthquakes.
A reinforced beam experiences a certain amount of yield when pressure is applied to it. These beams are usually divided into two separate zones, a compression zone and a tension zone. Steel reinforcements in these two pressure zones ensure that the concrete of the beam does not crumble beneath its applied weight load. Since steel is stronger than concrete, the two substances act together to bear these heavy loads.
Such a beam may be singly or doubly reinforced. These designations refer to the types of pressure that can be applied to the beams. A reinforced beam that has steel supports in the tension zone is known as singly reinforced. A beam with steal supports in both the compression and tension zones is generally referred to as doubly reinforced. Doubly reinforced beams are typically easier to construct and allow the beam to remain thinner than the singly reinforced kind. When weight is applied to the beam, the steel will provide yield without creating the need for a large beam, while the concrete ensures that the steel does not, in turn, snap under the pressure.
Beams may be reinforced diagonally as well as in a perpendicular manner. This helps avoid an excess of joints during construction and allows a more streamlined appearance in the architecture of the building. These diagonal reinforcements are equally secure when providing support during an earthquake.
Commercial buildings generally contain a large amount of reinforced beams. They are typically certified by building inspectors prior to the completion of construction and use of the structure. Most countries have set regulations for commercial construction that apply to the assembly and weight-bearing capabilities of reinforced beams. If a beam is improperly reinforced or not reinforced at all, it cannot bear the vertical weight of additional stories in a building, and has a high probability of collapse when stress is put on it.