Steel fabrication for infrastructure

Steel fabrication contributes significantly to the development of various infrastructural components, ensuring safety, durability, and strength in different sectors like construction, transportation, utilities, and renewable energy.

Processes involved in steel fabrication

Cutting and shaping: this step involves cutting the steel into the desired shapes and sizes. Techniques such as sawing, shearing, or using Computerised Numerical Control (CNC) (computerised systems operate and control machine tools) are employed to cut and shape the steel according to the required specifications.

Welding and assembly: once the steel pieces are cut and shaped, they're assembled together using welding techniques. Welding helps join different parts of steel to form the desired structure or component. This process requires expertise in different welding methods like arc welding, metal inert gas welding, tungsten inert gas welding, etc.

Surface treatment and finishing: after the welding and assembly, the fabricated steel might undergo surface treatments and finishing processes to improve its appearance, durability, and resistance to corrosion. This can involve processes such as sandblasting (a stream of abrasive particles is propelled at high velocity against a surface to remove contaminants, or prepare it for coating), painting, galvanising (coating with a protective layer of zinc), powder coating, or applying other protective coatings (like polyurethane, epoxy etc.) to enhance abrasion as well as corrosion resistance.

Types of steel used in fabrication for infrastructure

Steel fabrication for infrastructure involves various types of steel, each chosen for specific properties and purposes. Here are some common types:

Carbon steel: this is the most widely used type due to its affordability and versatility. It contains varying percentages of carbon depending on the requirements and end applications, making it strong and suitable for a range of applications like bridges, pipelines, and buildings.

Structural steel: specifically designed for structural components, it offers high strength and excellent weldability. It's commonly used in beams, columns, plates, and angles of buildings and bridges.

Rebar (reinforcing steel): used to reinforce concrete in infrastructure projects like bridges, highways, and buildings. It adds ductility and tensile strength to RCC structures, enhancing their durability and load-bearing capacity.

Stainless steel: infrastructure elements exposed to very low or high extreme temperatures or corrosive environments often incorporate stainless steel, such as in bridges, handrails, and architectural elements.

Alloy steel: comprising various alloying elements like chromium, nickel, or manganese, alloy steels are engineered to exhibit specific properties like enhanced strength, fatigue strength, wear & tear resistance, toughness, or corrosion resistance. They find applications in critical infrastructure components, including pipelines and structural supports.

Tool steel: designed for tool manufacturing due to their high hardness, heat resistance, shape stability and durability. Though not as common in general infrastructure, they're essential in specialised construction equipment and tools.

Where is steel fabrication used in infrastructure?

Bridges: steel fabrication forms the backbone of bridge construction. Beams, girders, trusses, and structural elements of bridges are often made of fabricated steel due to its strength, durability, and flexibility. Steel enables the creation of long spans, allowing for innovative bridge designs and efficient load-bearing capabilities.

Buildings and skyscrapers: in modern construction, steel fabrication is integral to creating the framework of high-rise buildings and skyscrapers. Structural steel beams and columns provide the necessary support for these tall structures, offering strength and flexibility while allowing for open and customisable interior spaces.

Highways and transportation: steel fabrication is utilised in transportation infrastructure for constructing support structures, guardrails, signposts, and other components along highways, roads, and railways. Steel's durability ensures these elements withstand constant exposure to environmental factors and heavy traffic.

Tunnels and underground structures: in tunnel construction, fabricated steel is used for structural supports, reinforcement, and lining systems. Its strength and adaptability make it suitable for ensuring the stability and safety of underground passages.

Offshore structures: steel fabrication is crucial in the construction of offshore platforms, rigs, and marine structures. These demand durable materials that can withstand harsh marine conditions, making steel an ideal choice due to its corrosion resistance and strength.

Aerospace and aviation infrastructure: specialised alloy steels are crucial in the aerospace industry for constructing aircraft hangars, runways, and support structures. These steels offer high strength-to-weight ratios, critical for aircraft components and infrastructure.

Waterfront structures: stainless steel is often used in waterfront developments for constructing features like piers, balustrades, and architectural elements due to its resistance to corrosion from saltwater exposure.

Power and energy infrastructure: from power plants to transmission towers, steel fabrication is essential for the construction of infrastructure in the energy sector. Steel supports the creation of reliable and durable structures necessary for power generation, transmission, and distribution.

The choice of steel type depends on the specific demands and environmental conditions of each infrastructure project. Engineers and fabricators select the appropriate steel grades to ensure the safety, longevity, and functionality of the structures being built.