Over the course of history, buildings have been made from a variety of materials including wood, stone, and brick, but the most popular remains steel, used for everything from creating extremely strong structural framework to external cladding to protect against harsh elements. The World Steel Association – which represents over 160 steel producers – estimates more than half of the steel produced on the planet is used in construction.
From bridges to buildings, structural steel is extremely durable, and has a high strength-to-weight ratio, making it ideal for massive structures such as city skyscrapers. With the ability to be manufactured in an array of shapes, steel is produced to client specifications, which enables structures to be completed quickly. And unlike many other products, steel scrap can be melted and re-made over and over again, benefiting the environment. In fact, about 30 percent of the new steel on the market today is made from recycled content.
From Tokyo to Toronto and London to Lagos, steel remains the building material of choice. Able to withstand hurricanes, earthquakes, floods and other natural disasters, steel plays an integral role in reinforcing bars, columns, studs and joists, and sheet products such as internal walls and ceilings. And with the population of the planet expected to increase by 2050 to 9.8 billion – and more of us living in large metropolitans – the need for steel structures continues to grow.
A valuable commodity
With an increase in the use of steel for residential buildings in the years following World War II, the material gained considerable momentum in the 1950s and 1960s for commercial buildings, which required materials that were non-combustible and strong enough for tall structures. Today, the Steel Framing Association estimates 30 to 35 percent of all non-residential structures across America are made with cold-formed structural steel and non-structural framing.
In terms of crude steel production, China still holds the number one position, with an annual tonnage of 831.7 – over half of the world’s total steel production – followed by Japan at 104.7, India at 101.4, the United States at 81.6, and Russia in fifth place with a yearly tonnage of 71.3. Other top steel-producing nations include South Korea, Germany, Turkey, Brazil, and Italy. Led by companies such as ArcelorMittal, the China Baowu Group, the NSSMC Group, the HBIS Group, and POSCO, the market for structural steel shows no signs of significant slowdown.
Today, the largest importer of steel is the United States which, in 2018, imported 16.2 million metric tons. According to the U.S. Department of Commerce, American imports for 2017 represented approximately nine percent of all steel imported globally, and this was “more than 25 percent larger than that of the world’s second-largest importer, Germany.”
For the United States and the construction industry, steel is big business. Importing steel from over 85 countries – led by Canada, Brazil, and Mexico – the U.S. received over 760 thousand metric tons from each country, and has seen steel import growth of 192 percent in the past decade; over half of the steel produced in Canada and Mexico is exported to the U.S. And while import levels have fluctuated historically, falling 12 percent in 2015 and 15 percent in 2016, the amounts of steel coming into America steadily rise, and represent $15.4 billion U.S. as of September, 2018. And while these figures represent a variety of steel types, including stainless, pipe and tube, semi-finished and others, much of it finds its way into building applications.
Vital to the construction sector, steel continues to be a formidable economic driver. With a history going back over 160 years, the American Iron and Steel Institute (AISI) states that the industry in the U.S. accounts for over $520 billion in economic output, and almost two million jobs, including direct, indirect (supplier), and induced impacts, as of 2017. “These workers earned over $130 billion in wages and benefits. All told, the industry generated $56 billion in federal, state and local taxes,” stated the AISI in a recent summary.
Of course, it is impossible to discuss steel without raising the issue of tariffs imposed under the Presidency of Donald Trump, which began with solar panels and washing machines, extending to steel and aluminum at 25 percent and 10 percent about a year ago. While some economists and business leaders criticized the move, the AISI stated this February the steel tariffs are working. “The Administration’s trade actions and tax and regulatory reform policies, in addition to the strong economic climate enabled by those policies, have allowed the American steel industry to begin to recover after more than a decade of low capacity utilization and weaker earnings due to repeated surges in imports fuelled by global steel overcapacity,” stated Thomas J. Gibson, AISI President and Chief Executive Officer in a release. “Capacity utilization at existing mills has increased in recent months to over 80 percent – levels not seen in the last ten years. Some shuttered plants are being re-opened, laid-off workers are going back to work and companies are making investments in new steel production facilities.”
Although optimistic about the future of steel, Gibson cautioned recent progress will disappear if tariffs are ended prematurely, stating Section 232 tariffs on imports of steel and aluminum are “critical to ensuring steel remains a vital asset for our national and economic security,” especially with China producing record-breaking amounts of steel and potentially flooding the market.
Touching the sky
With many major cities worldwide experiencing construction booms, steel structures are being built in record-breaking numbers. Pushing the limits of architecture and engineering means even taller skyscrapers. In Melbourne, the capital of the Australian state of Victoria, recent years have seen controversy over the increasing height of buildings. One recent project called for a massive, 356 metre (1,168) foot tall building, which has drawn considerable controversy, as the tower would become the tallest in Southbank, an inner city suburb.
Despite some naysayers, there is no denying steel’s integral role in construction. With ‘steel skyscrapers’ classified by the U.S.-based Council on Tall Buildings and Urban Habitat as structures “where the main construction vertical and lateral structure elements and floor systems are constructed from steel,” many of the world’s largest buildings are composed mainly of steel. Many in the Top 10 are iconic and instantly recognizable for their glimmering reflective exteriors and unique structural skeletons, such as the 73-storey U.S. Bank Tower in Los Angeles, the timeless Art Deco design of New York’s Chrysler Building at 319 metres (1,047 feet), and Chicago’s 88-storey Aon Center, the third largest steel building in existence.
While other building materials certainly have their place, the use of steel for building massive skyscrapers in major cities worldwide cannot be denied. Respected for its durability, adaptability, cost-effectiveness, design flexibility, fire and earthquake resistance, strength and beauty and ability to be recycled over and over, steel will continue to play a role in urban construction for years to come.