In this article, we’ll categorize beams based on their construction materials, support configuration, and other unique aspects. Beams are structural members that undergo transverse loads, causing bending moments and shear forces along their length. They are utilized in various ways in structures. Let’s delve into each classification in greater detail.
Construction Materials
The categorization of beams based on the construction materials is discussed as follows: –
Concrete Beams
The materials used for this type of beam are cement concrete. There are different types of concrete beams constructed depending on their cross-section area and shape. These types of beams are mainly reinforced concrete beams used to carry the loads. Mainly, they can be categorized as rectangular beams and circular beams. In addition, there are other types of beams such as inverted T beams, flange beams, etc used in the construction.
Steel Beams
There are many types of steel beams that are considered as types of beams to carry the loads. Mainly, we identify the universal beam as the steel beam that carries the load. Further, it has a higher stiffness in the direction of bending. Further, there are beams like plate girders that are used to carry heavy loads. Steel pipes, C channels, Rectangular Hollow sections, Solid Pipes, etc. are also used as steel beams as applicable.
Timber Beams
Timber is a quite popular construction material in some parts of the world. Further, there are very large and tall structures constructed from the timer. Time beams are used as load-carrying elements in these structures. The treated timber is used in the construction as most of the time it is the concerned with the durability of the structures.
Composite Beams
The combination of two or more materials is used to form a composite material. This is done to enhance the stiffness of the beam. The use of steel and concrete is most common in this category. Steel and concrete composite beams are widely used in steel structures.
Based on The Types of Beam Support
Simply Supported Beam
There are two supports and they allow the rotation at the support. Thus, the edge of the beam is freed to rotate. The bending moment will be maximum at mid-span or near the mid-span based on the arrangement of the loads. The sheer force will be maximum at the supports.
Continuous Beam
When there are two or more supports, that beam is identified as a continuous beam. Depending on the boundary condition, there will be a bending moment in all supports. If the beam is designed assuming the knife-edge supports, there will be no bending moment at end supports.
If we are designing a concrete beam supported with concrete columns, the effect of the concrete columns or the stiffness of the concrete column shall be considered in the analysis. Analyzing knife-edge supports and column supports makes a considerable impact on the results.
Cantilever Beam
Whether the beam ends at the support or it continues to the other spans, the beam needs to be designed for the cantilever bending moment. No moment distribution can be made to the cantilever bending moment.
Other Special Types of Beams
Precast Beams
As the name says, they are types of beams that are cast separately and placed in the relevant location. This type of construction is now becoming more popular when there is a repetition of work. Beams can be cast in bulk and then they can be installed. This is a cost-effective method as well as saves time too.
The beam reinforcement could be the same as the normal beam. However, based on the boundary conditions, etc, there may be some adjustments in the reinforcement area. Special connecting details could be adopted based on the nature of the structure to maintain continuity.
Prestress Beams /Post Tension Beams
Prestress means, stressing of cables is done before the casting of the beam. In post-tension beam construction, we cast the beam first, and then the tensioning of cables is done. There are two stages in post-tension beam construction. That is the transfer stage and service stage. In the transfer stage, we design allowing for transportation. The service stage is the time at which we apply the load on the beam.
Post-tension and precast beams are widely used to support large spans. These beams are widely used in bridge construction. The article Bridge Design could be referred to get an idea about the design of post-tension beams.
Deep Beam
Supporting large spans, massive loads, etc. we construct the deep beams. Deep beams are more commonly observed in transfer floor construction. Column spacing is an increase in parking areas in multistoried buildings. Beyond that level, we place columns closely due to many reasons.
At this level, a deep beam is constructed to carry the load applied by the structure above the transfer floor. There are special procedures that need to be followed when the design of the deep beam.
Tapered Beam
Tapered beams are commonly constructed as architectural features. These types of beams are not widely constructed. Construction is much more difficult than the usual beam construction. Further, the arrangement of the reinforcements needs to be changed along the beam length. For, example, we have to make all the shear links in different sizes. However, these types of beams are more effective and economical in steel construction. We increase the depth of the section only where it is required.
In portal frame construction, this is practice. Further, the use of a tapered beam and column can bring the economy into the project. Beam Classification Based on Cross-Sectional Area based on cross-section, L shape, T shape, rectangular, There are types of beams such as “L” shape, “T” shape, etc constructed from different angle sections. Rectangular Hollow sections, Circular Hollow Sections, and solid sections of the rectangular and circular sections are also used as beam sections.
Also, read:
- Column Failure: Causes | Types | Prevention
- Stirrups: The Shear Reinforcement Bar
- Different Types of Foundation Used in Construction
