FEATURES OF THE USE OF СOR-TEN STEEL IN ARCHITECTURE AND CONSTRUCTION

ОСОБЕННОСТИ ИСПОЛЬЗОВАНИЯ СТАЛИ КОРТЕН В АРХИТЕКТУРЕ И СТРОИТЕЛЬСТВЕ

Пахомов Михаил Геннадьевич

студент, Национальный Исследовательский Московский Государственный Строительный Университет,

РФ, г. Москва

Карантиров Александр Владимирович

студент,

Национальный Исследовательский Московский Государственный Строительный Университет,

РФ, г. Москва

Быкова Татьяна Алексеевна

студент, Национальный Исследовательский Московский Государственный Строительный Университет,

РФ, г. Москва

Юдина Ирина Ивановна

преподаватель, Национальный Исследовательский Московский Государственный Строительный Университет,

РФ, г. Москва

ABSTRACT

This article discusses the features of using COR-TEN steel in architecture and construction of buildings and structures for various purposes; it identifies the advantages and disadvantages of this material, and it describes the prospects for the use of COR-TEN steel resistant to atmospheric corrosion in construction in the future.

АННОТАЦИЯ

В данной статье рассматриваются особенности использования стали кортен в архитектуре и строительстве зданий и сооружений различного предназначения; определяются преимущества и недостатки этого материала, а также описываются перспективы использования кортеновской стали, устойчивой к атмосферной коррозии в строительстве в будущем.

Keywords: COR-TEN steel, protection, durability, construction, art-design.

Ключевые слова: кортеновская сталь, защищенность, долговечность, строительство, арт-дизайн.

COR-TEN steel is a very durable, unpretentious, almost indestructible material. US Steel was developed this steel in 1930s. It gets its name from the fusion of the words "corrosion" and "tense", which indicates the ability to sustainably withstand environmental influences without the need for additional protection. COR-TEN is often called "eternal" steel with a velvety texture: its dense oxide film (rust) prevents further penetration of water to the metal, thus, patina-coated steel retains its brownish color forever.

Due to the special composition of alloying additives made of copper, chromium, nickel and phosphorus, under the influence of weather conditions, a uniform layer of rust forms on the surface of the steel, which subsequently protects the alloy from further penetration of corrosion inside, since the resulting patina becomes impermeable to oxygen and water. To obtain a good protective layer, COR-TEN must be exposed to atmospheric conditions with repeated alternation of wet and dry cycles.

The rate of change and final color depends on the ambient atmospheric conditions, as well as on the presence of pollutants in the air – sulfur will accelerate the oxidation process and give the patina a darker color. Frequent change of dry and wet cycles will also accelerate oxidation. In the first 10 years, due to the formation of a corrosive layer, the thickness of the sheet may decrease by several millimeters. In the future, the intensity of corrosion decreases significantly and tends to zero. It turns out that the rust itself does not allow the metal to oxidize further and ensures its durability. Speaking of durability: steel with a thickness of only 1 millimeter will last 250 years. At the same time, ordinary carbon steel of the same thickness will last only about 2 years on average.

Typically, this steel is commonly used in bridge construction, shipbuilding, power line construction, as well as in industrial and civil engineering as a material that does not require painting or other anti-corrosion treatment.  Due to the original and uniform shade of patina, steel has become widespread as a decorative material in the creation of sculptures and other art objects, and sometimes even in interior design. This combination of qualities makes it popular among both professional architects and private developers. COR-TEN harmoniously combines strength and stability with irresistible aesthetics, which allows you to create original and impressive architectural solutions. Thanks to the efforts of architects and industrial designers, the material resembling ordinary rusty steel on abandoned buildings has become an element of the decorative design of buildings specially designed taking into account its decorative properties.

It is also worth noting that in the marine atmosphere, which is saturated with salt aerosols, in seawater and in the atmosphere near some industry containing various corrosive agents up to strong acids, COR-TEN loses its anticorrosive properties and begins to rust in depth, after which the structure will be destroyed.

COR-TEN is divided into 2 types — A and B:

• COR-TEN A is usually a cold—rolled material. The thickness ranges from 0.5 millimeters to 3 millimeters. You can also hear that this type of COR-TEN is called “phosphoric". It is this type that is more often used for decorative and architectural purposes. It has a high resistance to weathering; the range of possibilities is 5-8 times greater than the potential of carbon steel. Externally, it looks like galvanized steel.
• COR-TEN B is a hot—rolled material in the form of rolled and thick-rolled products. This type of COR-TEN is usually called “vanadium". It is usually used for high-load structures (bridges, power lines, retaining walls, etc.). This type of COR-TEN is 4 times more weather-resistant than carbon steel. Externally, it can be distinguished from COR-TEN by the presence of scale, which gives the sheet a dark gray color. Usually, to remove stains and remove rolling scale, hot-rolled COR-TEN is sandblasted or acid treated.

It is worth noting that weather-resistant COR-TEN does not instantly change color to rusty. At first it looks gray, like galvanized steel, but over time, under the influence of weather conditions, it begins to become covered with a protective rust-colored patina. A layer of patina, if it forms naturally, usually appears after 2-3 years and over time begins to acquire an increasingly saturated dark color. For those who want to purchase COR-TEN immediately of a "rusty" color, manufacturers subject the metal to artificial oxidation. In order to stop the color change at a certain shade and prevent "rusty" stains, it is enough to cover the product made of COR-TEN with a colorless varnish.

• Despite the increased popularity of COR-TEN in world architecture and design over the past ten years, the fashion for rusty steel is still gaining momentum in Russia. Sculptors were among the first to use this material in their works, and architects followed them. This is how the facades of the following buildings appeared:
• BC «Ferrum» in St. Petersburg (TCHOBAN VOSS Architekten)
• RC « Zilart» in Moscow (Sergey Skuratov)
• Restaurant «Zoo Beer&Grill» in Moscow (Natalia Belonogova)
• Rzhevsky Memorial to the Soviet Soldier (sculptor Andrey Korobtsov architect Konstantin Fomin)
• BC «Aurora» in Yekaterinburg (Bureau R1)
• BC «Tovarishestvo Ryabovskoy Manufakturi» in Moscow (Mikhail Balko)

Now there are several analogues of COR-TEN, such as, for example, A606 steel, a metal with a unique composition including chromium, phosphorus and copper.

All conventional methods can be used to weld COR-TEN. To ensure a weather-resistant weld, the seam must contain the same metal alloy as the base metal.

Let us consider the main advantages of COR-TEN:

1. Weather resistance. This steel is capable of withstanding extreme weather conditions, including high humidity, heavy rains and snowfalls, as well as strong winds. This makes COR-TEN an ideal choice for construction in regions where weather conditions are a particular challenge
2. Aesthetic appeal. Its characteristic orange-brown patina gives buildings and structures a special uniqueness
3. Durability and reliability. It has a high degree of resistance to mechanical influences, including shocks and vibrations. Due to these properties, weather-resistant steel does not require high maintenance and repair costs, which makes it a cost-effective solution on a long-term basis

However, as with any material, COR-TEN has its drawbacks:

1. One of the main disadvantages of this material is its cost. COR-TEN is a relatively expensive material, especially compared to traditional building materials such as conventional steel or aluminum. This can significantly affect the cost of the project and limit its availability to some customers
2. It is also worth mentioning that for the first six months or a year, a layer of apatite can stain everything that touches it. But after this period of time, the rust will no longer leave traces
3. Another disadvantage of using COR-TEN is the need for proper installation and handling. Improper installation or operation can lead to premature wear or deformation

In conclusion, it should be noted that COR-TEN is a unique material that has a unique combination of properties. Its strength, durability and aesthetic appeal make it an integral part of modern architecture. Unsurprisingly, this material continues to win the hearts of both professionals and ordinary people, and is becoming increasingly popular in the construction industry.

References:

1. Weatherproof steel – COR-TEN. [Electronic resource]. URL:https://emk24.ru/wiki/spetsialnye_stali/atmosferostoykie_stali_corten_7082947/
2. COR-TEN steel. [Electronic resource]. URL:https://ru.wikipedia.org/wiki/%D0%9A%D0%BE%D1%80%D1%82%D0%B5%D0%BD%D0%BE%D0%B2%D1%81%D0%BA%D0%B0%D1%8F_%D1%81%D1%82%D0%B0%D0%BB%D1%8C
3. COR-TEN steel. Natural beauty. [Electronic resource]. URL:https://www.ssab.com/ru-kz/brands-and-products/cor-ten
4. COR-TEN steel. Interview with the manufacturer. [Electronic resource]. URL:https://youtu.be/yM7mhB0MHOc?si=uwgsxTNt3VXpY6ip
5. COR-TEN steel in architecture, construction, art. [Electronic resource]. URL:https://archiprofi.ru/journal/detail/modnaya-rzhavchina-stal-cor-ten-v-arkhitekture-stroitelstve-iskusstve_b916093/
6. COR-TEN “A”, “B”. What is the difference? [Electronic resource]. URL:https://steelmasters.ru/cor-ten-a-b-c-v-chjom-zhe-raznica/