A lot of folks think that the average building is constructed from just concrete and wood. Imagine their shock when they find out that apart from wood, rubber, electrical materials, etc., all go into constructing a building. Structural steel is one crucial element that holds up (literally) every building. The properties of structural steel make it ideal for specific kinds of buildings. If you are looking to build any structure, it might be essential to learn the properties of structural steel.
What is Structural Steel?
Structural steel is steel that has been shaped specifically for use during construction. It behooves the manufacturer to determine the composition of each structural steel. Invariably, the strength, composition, and size all depend on the need at that time.
Structural steel is a huge part of construction and is often used in constructing buildings, ships, etc.
Structural steel is described along three lines:
- Type and,
Composition of Steel
Structural steel suggests that the material contains some low carbon and manganese. In most cases, the carbon content can be as high as two percent. This works to increase the density of steel. If you want to increase the steel’s strength and ductility, you could do so by simply increasing its carbon content. However, this may depend on what you want to use the material for.
Some others may contain, although in insignificant amounts, aluminum.
Another significant element that makes up structural steel is iron.
Types of Structural Steel
Every structural steel contains carbon. However, the varying degrees of its content gives rise to the different types that exist. Below, you will find the different types of structural steel:
1. Carbon-manganese steel
This is also called mild structural steel. It is one of the strongest types of steel you’ll find. Thus, a lot of manufacturers prefer using it during construction.
2. High-strength, low-alloy steel
This type of steel is not quite popular. This is because it is a new entrant into the industry. It is also quite strong, although its strength comes from the chemical components that are added to it.
3. High strength, tempered steel
This is mostly used for structural construction.
Shapes of Structural Steel
In its basic definition, structural steel is steel shaped for construction. Hence, this ordinarily suggests that structural steel can come in different shapes. The most popular ones are:
This is a structural steel with a visible T-section.
This is a long piece of steel with a cross-section. It is typically rectangular.
This type of steel is either round or square-shaped.
This type of steel usually has an I-shaped cross-section. You will also notice flanges on either side of the steel. That is one quick identifier.
This has an L-shaped cross-section.
Advantages of Structural Steel
Some of the features which make structural steel a favorite for manufacturers include:
Generally, steel is very strong. (If you’ve stubbed your toe against one you must already know this.) Specifically, during construction, its strength comes into play.
The dead weight of steel is small compared to other materials in that category.
This makes structural steel great for high rise buildings like skyscrapers and the likes.
2. Possibility of Mass Production
You can fabricate steel materials quickly and without stress.
Furthermore, mass production is also possible. If you are looking to create multiple identical materials during construction, structural steel is ideal. A side benefit of this is that you get to save money.
Using structural steel to fabricate building materials is one of the least expensive routes to explore.
3. Capacity to be Restrengthened
You certainly do not want to have to pull down your building in a few years. Working with steel during construction makes sure that isn’t the case. This is because steel can be restrengthened every few years.
Simply put: at any point where you believe the material is getting weak, you can restrengthen. You would not have to dismantle, or pull down the building totally, to achieve this.
More so, you can reuse steel materials. You could even turn it into a different end product and use it.
Properties of Structural Steel
There are quite a number of properties structural steel possess. These characteristics determine the strength, durability, and usefulness of each product.
Hardness is the ability of a product to resist scratching. For steel materials, the results vary. Typically, you will have to use an indenter on the surface of the material during tests. The results will show you the hardness of the structural steel.
Using an indenter is one through which you carry out the test. The test in itself includes the Vickers hardness test and Rockwell hardness test.
2. Tensile Strength
Generally, structural steels are strong and durable. However, changing the chemical composition of each during production could affect its quality. For instance, adding either copper or nickel could improve the corrosion resistance of the metal. In the same vein, you can introduce sulfur and phosphorus to reduce the brittleness in any metal material.
To determine the strength of the steel, you have to conduct a tensile test. This would then let you know both the yield strength and ultimate strength of the material.
This feature is important because of a phenomenon known as fatigue failure. This is a situation where the steel fails due to cracks that form on its surface.
You may want to carry out fatigued tests to ascertain the stress compatibility of the product before use. You can explore any of the three: flexure test, rotating beam test, and axial-load test. For each of those, the material is introduced to various degrees of stress till it yields. At that point, you can then calculate the stress limit of the material.
4. Notch Toughness
The notch toughness of any steel material reveals whether the material will develop cracks easily or not. It is hardly possible to prevent the development of cracks —it is steel, after all. However, you can prevent the eventual collapse of your structure by choosing materials that develop cracks slowly.
5. Corrosion Resistance
Corrosion is the oxidation of a metallic material due to exposure to oxygen. Basically, it refers to the change you notice on steel and other metals when they are exposed to the air. The moisture in the atmosphere mixes with oxygen to cause changes to the metal.
In simple terms: corrosion is the same as rusting.
Corrosion is a natural phenomenon. It occurs more in areas that are close to saline water. Thus, if your property is on a beachfront, you have to be particularly mindful.
Under normal circumstances, structural steel has a low resistance to corrosion. However, you can take some steps to ramp up its resistance. For instance, you can coat each material with phosphorus, copper, and chromium, creating steel that is corrosion resistant.
An alternative is to use epoxy-coated reinforcement bars. However, this could compromise the material, resulting in disbanding.
Before venturing into construction, it might be helpful to get properly acquainted with what the process demands. One area that is of great importance is the quality and characteristics of the materials you intend to use. For huge buildings, especially, you cannot do without structural steel. Hence, learning about its properties puts you in an advantageous position.