Steel is a major component in bridge construction, which explains its ever-increasing usage in long, medium, and short span bridges, railway bridges, and even footbridges. Steel is known for its versatility, strength, and ductility, features that allow bridges to resist dead and dynamic loads effectively. So, what are the main types of steel used in bridges?
The main types of steel used in bridges include carbon steel, heat-treated carbon steel, stainless steel, and weathering steel. The steel used in bridges often depends on the bridge type. Steel’s versatility allows it to be used as a primary member or in safety components.
In this article, we’ll examine the main types of steel used in bridge construction while also discussing some of the benefits of using steel as a construction material. Continue reading.
Steel: A Brief Overview
Steel has been a mainstay in both large and small-scale construction due to its ductility and tensile strength, which allow it to deform and bend considerably before breaking. The higher the yield strength, the harder it will be for the steel to break.
1. Carbon Steel
Carbon steel is a type of steel with a higher concentration of carbon than other types of steel. As revealed by Monroe Engineering, carbon steel’s carbon content goes up to 2.5%, which is considerably higher than other types of steel whose carbon content ranges from 0.05-0.3%. While a 2.5% carbon content might sound insignificant, it furnishes carbon steel with several advantages.
Advantages of Using Carbon Steel in Bridges
Disadvantages of Using Carbon Steel in Bridges
2. Heat Treated Carbon Steel
Heat-treated carbon steel has incredible strength that’s derived from altering steel’s physical properties through strategic heating and cooling. This type of steel is widely used in bridge construction and other large projects due to its increased ductility and tensile strength.
Below are some of the types of heat treatments that carbon steel undergoes to alter its properties:
Advantages of Using Heat-Treated Carbon Steel in Bridges
3. Stainless Steel
Stainless steel is known for its strength, aesthetic appeal, and corrosion resistance properties. These features have played a pivotal role in the widespread use of stainless steel in bridges. Long-span bridges, highway bridges, pedestrian bridges, and even railroad bridges have become increasingly reliant on stainless steel.
The increased usage of stainless steel is due to its durability and ability to maintain a neat appearance despite long term usage.
Initially, stainless steel was primarily used on safety components such as handrails and guardrails. Over the years, the role of stainless steel in bridge construction has increased exponentially, which explains their use in structural components like decks, suspension systems, or tie-rods.Stainless steel is also used in bridges to fabricate bearings and other parts that are susceptible to corrosion. The main disadvantage of using stainless steel is its relatively high cost, which often limits its use in primary parts of the bridge.
Advantages of Using Stainless Steel in Bridges
Stainless steel has several advantages that allow for its usage in the construction of bridges. Below are some of the main advantages of stainless steel.
4. Weathering Steel
Weathering steel is a type of steel with enhanced resistance to elements of corrosion. This steel has a rustic appearance that allows it to blend seamlessly with the immediate environment. The impressive resistance to gradual corrosion and rust has seen the increased usage of weathering steel in bridges located in acidic or alkaline conditions.The use of weathering steel in the construction of bridges is tipped to continue increasing in the future, especially in saltwater environments where most metallic structures are prone to rust.
Advantages of Using Weathering Steel in Bridges
Bridge construction requires high-quality steel that can withstand corrosion, rust, and other forces that come into play once-dynamic loads are introduced. The most commonly used steel in bridges includes carbon steel, heat-treated carbon steel, stainless steel, and weathering steel.
Stainless steel and weathering steel bridges are ideal for bridges constructed in acidic or alkaline conditions as they’re corrosion and rust-resistant. Heat-treated carbon steel is also great for use on bridges, more so due to its moldability, durability, and strength.