The optimisation of construction materials, including the size reduction of structural system components, is fundamental in the modern construction of high-rise buildings. Composite structural components consisting of concrete and steel are a sustainable solution. This research paper investigates the use of composite mega columns, with hot-rolled steel sections fixed in concrete, as vertical structural systems. Tests were conducted to explore maximum capacity, displacements, stress distribution, ductility, and stiffness, culminating in suggested simplified design methods based on European, Chinese, and American codes.

Paper abstract

“Steel reinforced concrete (SRC) columns are widely used in high-rise buildings, since they provide larger bearing capacity and better ductility than traditional reinforced concrete (RC) columns. This type of structural system is not currently explicitly addressed in the actual design codes. The paper aims at presenting the behaviour of a new configuration of mega columns - isolated steel reinforced concrete (ISRC) columns. A two-phase test was conducted on scaled ISRC columns designed based on a typical mega column of a super high-rise building. Phase 1 of the study includes six 1/4-scaled ISRC columns under static loads: every two of the specimens are loaded statically with the eccentricity ratio of 0, 10%, and 15%, respectively. Phase 2 of the study includes four 1/6-scaled ISRC columns under quasi-static loads: every two of the specimens were loaded under simulated seismic loads with the equivalent eccentricity ratios of 10% and 15%, respectively. A finite element analysis (FEA) was conducted as a supplement to the physical tests to provide a deeper insight into the behaviour of “mega columns”. An extended Plastic Distribution Method is defined to evaluate the capacity of the specimens. The method is based on simplifications similar to those proposed in EC4 [1]. The scope of this latter standard is limited to the consideration of one single steel profile. The method is validated by comparisons with experimental and with numerical simulation results using advanced finite element programs, showing a good accuracy in results.”

Research paper, abstract, and images: © Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin
Intro: Constructalia

Related link(s)

Performance and capacity of composite mega columns with encased hot rolled steel sections

Headlines throughout the world reveal that a global energy transition is underway. Oil and gas and electricity companies are announcing massive investments and strategic moves that embrace renewable energy.

Steel: a key material in a less carbon-intensive world

Renewable energy, which includes solar, wind, geothermal, hydro, and others, is at the centre of the transition to a less carbon-intensive society, which also puts steel at the centre of the conversation.

“Steel is required by each of these markets. Without steel, none of the renewable energy sources would be possible. Every renewable energy structure – a wind turbine, a solar panel - requires steel,” says Johannes De Schrijver, CEO of ArcelorMittal Projects.

An expansion of renewable power capacity

According to the International Energy Agency, renewable power capacity is set to expand by 50% between 2019 and 2024. This increase of 1200 GW is equivalent to the current total power capacity of the United States. Solar is expected to account for nearly 60% of the anticipated growth and onshore wind 25%.

Steel will play an important role in all renewables, including and especially solar and wind. Each new MW of solar power requires between 35 to 45 tons of steel, and each new MW of wind power requires 120 to 180 tons of steel.

The solar market

The solar market is divided into two areas. The first are smaller-scale rooftop panels mounted on homes, museums, and stadiums. The second is utility-scale projects, which are larger consumers of steel. These plants produce a standard 100 to 300 MW of energy while some in development are approaching 1000 MW.

Johannes De Schrijver notes: “These are basically small power plants, football fields full of solar panels. If you consider that each new MW requires 35 to 45 tons of steel, that’s a tremendous opportunity for us. This is an area that has our attention.”

Solar technologies

Solar power plants use three technologies, all of which use steel in the structure on which the PV modules or mirrors are attached:

• Solar Photovoltaic (PV) – panels are mounted on a fixed or moving structure that allows the panel to be optimally oriented to the sun throughout the day; the moving structure is gaining ground on the fixed structure with tracker technology accounting for half of all PV structures by 2025.
• Concentrated Solar Power (CSP) - panels with lenses that focus the sun’s ray on a small cell with a much higher energy generation capacity.
• Concentrator Photovoltaics (CPV) - converts sunlight to electricity by PV cells made of semiconductor materials; usually the material is salt, which becomes liquid and generates steam to create electricity.

ArcelorMittal has been a key player in supplying steel to major solar projects around the world including the Beryl Solar Farm in Australia and Mohammed Bin Rashid Al Maktoum Solar Park in Dubai as well as solar farms in Chile, Egypt, France, Israel, and the United States. The company is also finalising agreements with power-generating companies on solar plants using CSP or CPV technologies. One is the first of its kind that combines both Solar PV and CSP for a revolutionary capacity of 950 MW of energy.

Steel in the wind energy market

Steel is also a major contributor to wind energy, which can be grouped into three key markets:

• Onshore wind farms - relatively small and produce between 2 and 3 MW of power per turbine. A variety of steels is used for the structural tower itself, the house of the turbine, the turbine blades, plus electrical steels for electricity generation
• Offshore wind farms - much larger, with recent turbines producing 5 to 8 MW of energy. Offshore wind consumes more steel than onshore and is an area of interest among investors. Offshore has two advantages: the ability to go much higher with no obstructions and the free flow of wind. Offshore requires a combination of steels to support the huge foundations that are anchored to the sea bed. Steel is also found in the structural tower itself and the blades, which are much thicker and longer.
• New generation wind farms – these wind farms go the distance, literally. These farms will be built even further from shore, requiring a floating structure. Each turbine will produce 7 to 12 MW of energy.

ArcelorMittal: supplying steel to windfarms

ArcelorMittal has been a supplier of steel to some of the world’s largest windfarms, including:

• BorWin3, a 900 MW offshore wind grid connection in the German North Sea.
• East Anglia One, a 714 MW wind farm in the North Sea off the coast of England.
• Greater Changhua, a 2.4 GW wind farm in the Taiwan Strait.

ArcelorMittal Global R&D plays an important role in supporting this market through the development of new steel products and solutions:

• Magnelis®, a breakthrough corrosion resistant steel product, has enjoyed much success in the solar energy market. Magnelis® is the industry’s reference product for ground mounted structures and the product of choice in harsh outdoor and indoor environments.
• A-motion is a new steel solution for solar panels created by ArcelorMittal. A-Motion is a single-row, self-powered, and wireless solar tracker which features a wind-friendly design dimensioned to be safe in any position with no stow position required. With a limited number of components, a global supply chain with possibilities of local content and reduced O&M, the product answers the market’s needs.

“The future of steel in the energy transition is exciting,” says Johannes De Schrijver. “As the world’s largest steel producer with extensive downstream capabilities and fabrication and construction knowledge, we are in an excellent position to provide safe, sustainable steel for the future of energy.”

Text: ArcelorMittal
Images: ArcelorMittal

Related link(s)

East Anglia One wind farm

Mohammed Bin Rashid Al Maktoum solar park

BorWin3 offshore wind farm grid connection

From 21 September to 11 October 2020, all eyes will be on the French Open / Roland-Garros tournament. While encouraging Novak, Serena, Rafael, or Roger, we invite you to admire the new retractable roof of the central court! Thanks to ArcelorMittal Rodange rails, your favourite players will be protected from the rain.

Premium rails provided in record time for the French sports monument

The Rodange site produced the 44 crane rails used for the construction of the retractable roof of the court. The A150 rails are the largest in our DIN range and were produced in 110CrV of superior quality. This shade has long been exclusively developed by ArcelorMittal with special straightening to ensure perfect track alignment.

The rails were mainly produced for the Philippe Chatrier central court roof. Once the rails were manufactured, the finishing operations were managed and organised in Yutz, France for:

• Cutting: The rails were cut to length according to customer specifications, including 45° corner cuts while respecting the required lengths with a tolerance of +/- 1mm.
• Hardness: The A150 are the highest quality in the range.
• Handling: Made with textile straps only, without magnets or chains, despite the size of the rails (the A150 are the largest rails in the range of crane rails produced in Rodange).
• Fast delivery

In total, it took only two months between ordering and shipments to provide the end customer with completely finished rails - from production to delivery. Thanks to good internal cooperation, we were able to provide the customer with a complete solution.

The revival of an iconic tennis court

Built in 1928, the Philippe Chatrier central court has undergone a complete renovation to modernise the stands and build a retractable roof.

This roof will not only allow the organisation of night games, but will also protect players from the rain in case of bad weather. It is composed of 11 panels of 100 metres and 350 tonnes each which slide on our rails. Thanks to our high quality products, this 3850-tonne roof will open and close in 12 minutes.

Click here to see the construction of the retractable roof.

Text: ArcelorMittal Luxembourg, Constructalia
Images: ArcelorMittal Europe
Video: Roland-Garros

Related link(s)

Philippe Chatrier Central Court at the Roland-Garros / French Open

Équerre d'argent 2019 winners: A special jury prize for the Roland Garros Stadium

Retractable roof of the Philippe Chatrier central court at the Roland-Garros Stadium

Retractable roof mechanism of the Philippe Chatrier central court at the Roland-Garros Stadium

Philippe Chatrier central court at the Roland-Garros Stadium

When it comes to choosing materials, steel, because of its exceptional physical and mechanical characteristics, is the most popular amongst designers. It can be used to rapidly build economical, durable, and safe structures. The steel used to make hot-rolled sections, which can themselves be indefinitely recycled, is made from recycled scrap. It is particularly suitable for machining and shaping. However, it tends to react with agents in the atmosphere to form stable thermodynamic bonds – ferrous oxides and/or salts.

The ability of steel to revert to its natural or original state is called corrosion. In layman’s terms: steel rusts!

Suitable corrosion protection for long-lasting steel

The primary quality of steel - i.e. its ability to retain its physical and mechanical strength, or in the case of a steel structure, its load bearing capacity - is generally long-lasting and is only compromised when corrosion reduces its cross section to such a degree that safety is adversely affected.

The service life of a structure depends on the rate of reaction between the steel and its environment. These reactions depend on the nature and concentration of the corrosive agents present.

Corrosion protection of structures must therefore be considered as intervening in this process in order to prevent the reaction or greatly reduce the rate.

Large numbers of steel structures, some of them a hundred years old, which have benefited from the combination of a suitable corrosion protection treatment and regular maintenance, show impressively the potential of steel. However, these types of structures, requiring high maintenance costs, are no longer acceptable today.

New requirements govern the design of the steel structures of the twenty-first century:

•    Environmental protection policies enforced at both the national and international level have led to a considerable reduction in the amount of corrosive load in the atmosphere over the last twenty years. This has resulted in a noticeable drop in the average corrosion rate of steel and zinc as well as improved resistance of coating systems.

•    The design of steel structures is substantially improved through the effectiveness of welding procedures and the vast range of rolled sections available thus contributing positively to ensure that corrosion protection systems have long service lives. Maintenance and renovation costs continue to fall because the amount of exposed surface area has been greatly reduced and ease of access improved. The ability of new coatings to resist the stresses in their surroundings has been increased considerably. New inexpensive coating methods are employed in fabrication shops and on construction sites.

•    Zinc baths have sufficient capacity and are large enough to allow widespread hot-dip galvanisation of steel structures involving large components.

•    Combining the hot-dip galvanisation technique with adapted paint systems for zinc coatings - so called duplex systems – renders maintenance unnecessary with, in most cases, the corrosion protection not requiring any attention for the entire service life of the structure.

•    Corrosion protection is becoming an integral part of the fabrication process for steel structures.

Text: ArcelorMittal Commercial Sections
Images: ArcelorMittal Europe - Long Products, ArcelorMittal, ArcelorMittal Europe - Flat Products

Related link(s)

Corrosion protection of rolled steel sections using hot-dip galvanization

Corrosion Protection: Hot-dip Galvanizing of Structural Steel

Corrosion Protection: Hot-dip Galvanizing of Structural Steel

We value our partners. We are proud to cooperate with the companies and institutions that count on ArcelorMittal's technical know-how and expertise in their mission to create innovative, sustainable, and value-added solutions for their key markets. As our partnerships continue to grow, so has our newest Constructalia section – Partners.

Steel for construction

Our high quality steels are the perfect base for the creation of elements or finished products for use in a wide scope of the construction market. From heavy plates to organic or metallic coated coils, our production portfolio meets the highest demands in terms of resistance, corrosion protection, and aesthetics.

Meet our partners utilising our extensive Granite® range or corrosion resistant Magnelis®: Blachdom Plus, Budmat, and Regamet in their roofing solutions; BUCON for their steel tanks; Metpol with their plasterboard solutions; Meteor Systems and Zimmermann in their horticultural and agricultural systems; and InQuik for their innovative bridges.

Discover: Metal Union’s application of our metallic coated steels in their profiles, Gagnepark’s usage of sections and Cofraplus® for their multi-storey car parks, and Matière’s patented bridges with our heavy plates.

Steel promotion

From partnerships with associations promoting steel as a building material to new technologies and construction solutions with steel – and everything in between – we work closely with our partners to disseminate knowledge about steel in construction.

A new addition to our Partners section is ConstruirAcier, who inform and advise architects, engineering offices, and investors on the economic and environmental challenges faced by steel in architecture.

Text: Constructalia
Images: Blachdom Plus, BUCON, ConstuirAcier, Gagnepark, Matière, Meteor Systems, Metpol

ArcelorMittal has been recognised as a Steel Sustainability Champion for the third year running by the World Steel Association (worldsteel).

A perfect run

The accolade for 2019 maintains ArcelorMittal’s perfect run as a Steel Sustainability Champion since the programme was launched in 2017. Being named a Sustainability Champion distinguishes the steel companies who, like ArcelorMittal, are leading by example in creating a truly sustainable steel industry. The programme seeks to encourage other steel companies to increase their efforts, set higher standards, and demonstrate a strong commitment to sustainable development and the circular economy.

Dedication to sustainability

This designation reflects ArcelorMittal’s dedication to worldsteel’s sustainable development charter; the company’s regular and transparent reporting on its environmental, social and economic performance; our commitment to providing a safe and healthy work environment for steelworkers; and our success in 2019’s Steelie Awards, where the ‘Excellence in sustainability’ category was won for our Climate Action Report.

Worldsteel represents steelmakers in every major steel-producing country, as well as national and regional steel industry associations and steel research institutes.

Inventing smarter steels for a better world

Brian Aranha, executive vice president, head of strategy, CTO, R&D, CCM, global automotive, communications and corporate responsibility, ArcelorMittal said, “As the world’s leading steel company, we are inventing smarter steels for a better world because we recognise that sustainability sits at the heart of securing our license to operate, into the future. Extending our sustainability champion status for the third straight year is a confirmation of our dedication to making sustainable development a priority for our business.”

Text: ArcelorMittal Corporate Communications
Logo: worldsteel