Steel Application- Infrastructure
According to the UN's population forecast from July 2015, world population will reach 8.5 billion in 2030 and 9.7 billion in 20501 accompanied by rapid urbanisation. As the need for buildings and infrastructure continues to grow worldwide reducing consumption of natural resources and emissions will be crucial for future sustainability.2
Steel is affordable, readily available and sturdier than other metal alternatives (like aluminum) due to its high strength and durability. Steelmakers around the world are finding construction solutions through steel that allow for energy-efficient and carbon-neutral buildings. These solutions reduce the environmental impact over the structure's life cycle. New designs also account for the end of the structure's life- allowing parts of buildings to be recycled and reused after demolition. While buildings currently account for about 20% of global greenhouse gas emissions, they also present many opportunities for reducing emissions and mitigating climate change.3
Due to its aforementioned strength and affordability, steel can also provide the solution to infrastructure and construction needs in developing countries and in places that are prone to experiencing extreme weather. Many protective coastal and wind-resistant structures are constructed with steel.
How Steel is Used in Buildings and Infrastructure
The possibilities for using steel in buildings and infrastructure are limitless. The most common applications are listed below4 .
● Structural sections: these provide a strong, stiff frame for the building and make up 25% of the steel use in buildings.
● Reinforcing bars: these add tensile strength and stiffness to concrete and make up 44% of steel use in buildings. Steel is used because it binds well to concrete, has a similar thermal expansion coefficient and is strong and relatively cost-effective. Reinforced concrete is also used to provide deep foundations and basements and is currently the world’s primary building material.
● Sheet products: 31% is in sheet products such as roofing, purlins, internal walls, ceilings, cladding, and insulating panels for exterior walls.
● Non-structural steel: steel is also found in many non-structural applications in buildings, such as heating and cooling equipment and interior ducting.
● Internal fixtures and fittings such as rails, shelving and stairs are also made of steel.
For Infrastructure
● Transport networks: steel is required for bridges, tunnels, rail track and in constructing buildings such as fueling stations, train stations, ports and airports. About 60% of steel use in this application is as rebar and the rest is sections, plates and rail track.
● Utilities (fuel, water, power): over 50% of the steel used for this application is in underground pipelines to distribute water to and from housing, and to distribute gas. The rest is mainly rebar for power stations and pumping houses.