Over the course of time, materials used in constructing a building have changed as construction techniques evolved. From naturally occurring substances like clay, rocks, sand, and wood to man-made products such as concrete, cement composites, and brick, builders use all sorts of materials in construction. But the prominence of steel in building construction has remained unchanged as the major construction material to build modern structures.
The interesting fact about steel is that nobody had any idea how to incorporate it in constructing structures until the 19th century. If you go through the history of the skyscraper, you will see that some of the earliest iron-framed structures were constructed during the late 19th century. But why is steel so important in building construction and what are its uses? In this article, we will discuss everything.
The importance of steel in building construction
Ensuring the structural integrity of the building is the single most important aspect of using steel in construction. Steel has a high strength-to-weight and strength-to-size ratio. As a result, it is used for the structural framework of tall and large modern buildings where size and weight play a very important role.
But the main reason why steel is of utmost importance in building construction in Bangladesh is because of its ability to bond well with concrete. The high tensile strength of steel is utilized as a tension device in reinforced concrete to strengthen the solid and help the structure to hold everything together under strain. But steel has more usage in construction than just making bonds with the concrete.
Types of steel in building construction
There are different types of steel used in construction for different purposes. Some are used for load-bearing walls, some are used for reinforcement. Here are 4 types of steel that are commonly used in Bangladesh for different purposes.
Light gauge steel
This type of steel is mainly used in the facades of buildings, composite panels, and different cladding solutions. But they are amazing for load-bearing walls, purlins, and side rails. Light gauge steel products are known to offer a range of construction-related benefits most notably; the speed of construction, cost-effectiveness, and safety. They are also popular due to the products’ unique lightweight characteristics, making them easy and safe to handle during fabrication and construction.
Structural steel
As the name suggests, structural steel is used mainly to develop structures and build a building base. It is available in different specifications and sizes like- T-shape, Channel Sections, I-beam, Plate type, Bar or Rod-type, and so on. Structural steel has a high strength-to-size ratio that’s why they are also used in bridge construction. The main types of structural steel used in construction are usually resistant to water and corrosion. Structural steel is more environmentally friendly and highly recyclable.
Mild steel
This is carbon steel with only 0.04%-0.30% carbon content. This type of steel comes in different shapes and sizes ranging from flat sheets to structural beams. Mild steel is strong but most importantly it’s also very flexible, which prevents it from cracking when bent. This type of steel is very durable and can withstand great seismic movement, making it ideal for earthquake-prone areas. It is also very versatile and affordable compared to other types of steel.
Rebar steel
Rebar steel is also known as reinforcing steel, providing extra strength to concrete structures. It is a mesh of steel wire or steel bar used mainly in masonry structures. The surface of this type of steel is patterned to provide extra grip when bonding with other materials like concrete. Rebar is popularly used to reinforce concrete especially when you need to create a foundation for your building. Despite being strong in compression, concrete is weak in tension. But when rebar is cast into the concrete, the overall tensile strength increases, making it possible to carry heavy tensile loads.
Steel gradation
Now based on the physical properties and their compositions, there are 4 types of gradation available for steel-
> Stainless steel ( This type of steel contains a minimum of approximately 11% chromium )
>Carbon steel ( A combination of carbon and iron )
>Alloy steel ( This is basically carbon steel but in of other alloying elements )
>Tool steel ( This is also carbon steel but well suited for manufacturing tools )
Gradation helps when it comes to distinguishing each type of steel based on its distinctive properties including density, hardness, thermal conductivity, and so on.
Steel in building construction is one of the most essential materials. Unlike other man-made substances, steel can not be replaced with anything else when you are building a modern home. Cement is a major construction material but you can still build a modern multistoried home without it. But the same can not be said for steel. That is why it is important to have adequate knowledge about steel when building a house.
