Table of Contents

• What is a steel girder?
• Advantages of steel girders
• Types of steel girder bridges

The most common usage of steel is in the construction. According to the World Steel Association, nearly 50% of steel produced globally is consumed by the construction industry. Right buildings to infrastructures, steel is found everywhere. Modern bridges are also constructed with the help of steel girders. Here is what a steel girder is, its features, advantages and applications. The article also answers some frequently asked questions.
 

What is a steel girder?

Steel girders are extensively used in construction. The primary function of a steel girder is to provide horizontal support to the structure. In other words, a steel girder is a horizontal beam. Therefore, it is the main support system for structures such as bridges, buildings, etc.

Difference between steel girder and steel beam

Steel girders and beams both make primary support for the structure. If girders and steel beams serve the same purpose, then what is the difference between the two? The main difference between the two is size. Girders are larger-sized beams, which then connect to smaller-sized beams and together they support the whole structure of a building or bridge.

Here are the key features of steel girders:
 

• Load-bearing capacity: Girders have a huge load-bearing capability. They can take a lot of weight. Hence, they are extensively used in infrastructure such as bridges, flyovers, etc.
• Corrosion resistance: Steel is a corrosion-resistant material. Although it can corrode in certain conditions, there are various ways to prevent steel corrosion. Therefore, steel girders do not catch rust and corrosion quickly.
• Weather resistance: Steel is capable of withstanding extreme weather conditions including rains, snow, low and high temperatures and so on.
• Fire resistance: Steel melts at around 1400°C or more. As a result, steel girders do not melt or deform quickly in case of fire.

Advantages of steel girders

• Durability: Since steel girders are corrosion, weather and fire resistant, they last for decades. Therefore, they become the right choice to be used in construction and infrastructure projects.
• Maintenance: Steel girders require less maintenance. As a result, maintenance mostly includes regular inspection and required repairs.
• Speed of construction: Building steel girders might be a time-consuming process. However, once steel girders are ready, structures can be erected quickly.
• Environment-friendliness: Steel is an environment-friendly material. Scrapped steel can be easily recycled.

Applications of steel girders

Due to their features and advantages, steel girders are extensively used in bridges. Pedestrians, vehicles, railways, and many more kinds of bridges are made with steel girders. Some of the other areas where steel girders are deployed are flyovers, buildings, etc.
 

Types of steel girder bridges

As mentioned before steel girders are mainly used for constructing bridges. Some of the common types of steel girder bridges include:
 

• Box girder bridges: Box girder bridges are mostly constructed for longer distances. These bridges are usually made from hollow steel box, which forms a girder. The advantage of a box steel girder is it is capable of bearing torsional forces.
• Plate girder bridges: Steel girders are welded or bolted together to make steel plate girder bridges. These types of bridges are ideal for covering shorter distances.
• Truss girder bridges: In these kinds of a bridge, a series of steel triangles form a girder.
• I-girder bridges: These kinds of bridges use girders that are in the shape of an alphabet I. Usually, these kinds of bridges are economical and easy to fabricate. They are commonly used for shorter distances.

Concluding note

Although steel girders are common in the construction of bridges, a lot of factors influence the choice of material. For example, steel may corrode in humid conditions. Therefore, it may not be the right decision to use steel girders in geographies where humid conditions prevail. It is best to consult the steel experts to understand what kind of steel girder should be used in the project.
 

Are steel girders and steel beams the same?

Yes. Steel girders and steel beams are essentially the same components. What sets them apart is their size. Steel girders are larger in size as compared to steel beams. However, they serve the same purpose as supporting the structure.

How are steel girders manufactured?

The manufacturing and fabrication depend on the type of girder required. Plate girders are manufactured by welding and bolting steel plates. The thickness of the steel plate is determined by project requirements.

What are some of the examples of steel girder bridges in India?

Howrah Bridge, Kolkata, Godavari Arch Bridge located on the Godavari river in Rajamundry, Andhra Pradesh, etc., are some examples of steel girder bridges constructed in India.