Steel construction

 Steel structure building is a new type of building system, open up the industry boundaries between the

 real estate industry, construction industry and metallurgy industry, and set up a new industrial system,

 which is 

the steel structure building system that the industry is generally optimistic about.

Compared with traditional concrete buildings, steel structure buildings replace reinforced concrete with steel plates or sections, which has higher strength and better shock resistance. And because the components can be manufactured in the factory and installed on site, the construction period is greatly reduced. Due to the reusable steel, can greatly reduce construction waste, more green environmental protection, so it is widely used in the world, used in industrial buildings and civil buildings.

The application of steel structure buildings in high-rise and super high-rise buildings is becoming increasingly mature, and it has gradually become the mainstream construction technology, which is the development direction of future buildings.

Steel structure building is a building with a load-bearing structure composed of building steel. Beams, columns, trusses and other components, usually made of section steel and steel plates, constitute load-bearing structures. Together with the roof, floor and wall envelope, it forms an integrated building.

Building steel usually refers to hot rolled Angle steel, channel steel, I steel, H steel and steel pipe. A building whose components constitute a load-bearing structure is called a steel structure building. In addition, the L-shaped, U-shaped, Z-shaped and tubular thin-wall steel formed by the cold-rolled sheet steel, rolled or unrolled edge, as well as the load-bearing structure formed by the members made of small steel such as Angle steel, steel bars, etc., is generally called the light steel structure building. There are also suspension structure buildings using steel cables, which are also steel structure buildings.

The strength and elastic modulus of the steel is high, the material is uniform, the steel structure made of good plasticity and toughness, high accuracy, easy installation, high degree of industrialization, fast construction, but the corrosion resistance and fire resistance is poor, the need for frequent maintenance.

Advantage

1. Greatly save the construction time, the construction is not affected by the season

2. Increase the use area of residential space, reduce construction waste and environmental pollution

3. Building materials can be reused, driving the development of other new building materials industries

4. Good seismic performance, easy to transform in use, flexible and convenient, bring comfort and so on

5. High strength, light weight, high safety and wealth of components, reduce building costs

6. In line with the national sustainable development strategy, low-carbon, green, environmental protection and energy saving are key industries supported by the state

shortcoming

Due to the non-renewable land resources, the Ministry of Construction has ordered the ban on the use of traditional clay bricks, at the same time, China's steel production has reached 1 billion tons, the serious oversupply situation has forced iron and steel enterprises to find a new path, the introduction of foreign steel structure has been mature residential building system, while the construction industry and steel industry to find a new way out, so, Steel mills and building materials companies are at the forefront of steel structure housing.

1. Heat resistance, not fire resistance, need to be coated with fireproof paint

2. Vulnerable to corrosion, the surface needs to be coated with anti-corrosion paint to reduce or avoid corrosion and improve durability

Living example

Compared with brick-concrete structure, steel structure building has obvious advantages in environmental protection, energy saving, high efficiency and factory production. Shenzhen 325 meters high Diwang building, Shanghai Pudong 421 meters high Jin MAO Building, Beijing's Beijing-Guangzhou Center, Bird's Nest, CCTV new building, Water Cube and other large buildings have used steel structure, Beijing, Shanghai, Shandong, Liaoning, Inner Mongolia and other provinces and cities have begun to carry out steel structure residential pilot, of which, Beijing Jin Chen apartment has been listed as the Ministry of Construction residential steel structure system demonstration project. It is expected that the 21st century is the century of metal structure, and steel structure will become the backbone of the new architectural era. Humans began to use pig iron in the 1770s, and began to use wrought iron to build Bridges and houses in the early 19th century. The development history of steel structure has a long history than that of reinforced concrete structure, and its vitality is getting stronger and stronger. In the United States, more than 70% of the market for low-rise buildings such as non-residential buildings below two storeys is made of construction metal. Among the 101 super tall buildings that have been completed in the world, 16 are reinforced concrete structures, 59 are pure steel structures, and 27 are mixed steel concrete structures in different forms. It can be seen that the development of steel structure will certainly promote the rapid development of the construction industry, metallurgy industry, machinery industry, automobile industry, agriculture, petroleum industry, commerce, and transportation industry.

Asia's largest steel structure plant hall - On January 23, 2013, the plant hall of Qingdao International Horticultural Exhibition in China was capped with a leaf shape. Plant museum project is located in the north of Tianshui Road, Baiguoshan Forest Park, covers an area of 2.44 hectares, the total construction area of 22749 square meters, of which, the ground construction area of 13,522 square meters, the underground construction area of 9227 square meters, is one of the largest steel structure plant museum in Asia, the total cost of the project is 293 million yuan.

Because its shape is the shape of a leaf, a total of about 3,000 tons of steel structure is required, more than 14,000 bars are assembled, the total length of weld is more than 17,000 meters, and more than 15,000 pieces of special glass, so the construction is difficult and the process is extremely strict. The field splicing and welding task of the structure is particularly heavy, and the lifting difficulty is particularly large, and the total length of the weld seam of the steel structure on the site alone is more than 17,000 meters, which is equivalent to the welding amount of 10,000 tons of conventional steel structure engineering.

advantage

The "bulk weight to strength ratio" of steel is generally less than that of wood, concrete and masonry, so the steel structure is relatively light, 30% to 50% lighter than the reinforced concrete structure; In addition, the steel structure has a small section, which can increase the effective area of the building by about 8% compared with the reinforced concrete structure. The Songhua River steel truss Bridge, Yellow River Bridge and Shanghai International Hotel built in the early 20th century adopted steel structure. After the establishment of New China, the development speed of civil high-rise building steel structure has been further accelerated, and Beijing has accounted for six of the dozen high-rise steel structure buildings in the country: Jingguang Center (208 m high), Beijing Mansion (182 m high), International Trade Building (155.2 m high), Changfu Palace Hotel (90.9 m high), Shangri-La Hotel (82.7 m high), Industrial and Commercial Bank of China Head Office (48.3 m high), and the National Grand Theatre project under construction. Hundreds of large and small airports across the country will be designed with steel structures to speed up construction and increase space. It can be seen that the high-speed development of the economy needs steel structure.

Basic condition

The policy and technical conditions are in place. At the beginning of the year, the Ministry of Construction and the State Bureau of Metallurgical Industry jointly organized the construction steel Technical Coordination Group to formulate the National Construction steel Structure Industry "tenth Five-Year Plan and 2015 development plan Outline". The outline clearly states: The steel structure has a series of advantages such as high strength, light weight, good seismic performance, fast construction speed, provincial foundation costs, small footprint, high degree of industrialization, beautiful appearance, etc. In addition, the steel structure building also has a good sense of space, can be designed into a large number of open offices around the sky garden, central patio and reasonable elevator design can achieve the lowest energy consumption. Therefore, the steel structure is environmentally friendly and energy-saving building structure. Compared with the concrete structure, it is environmentally friendly and reusable, easy to industrialization of the structure, developed countries in the housing construction widely used steel structure. Financial Street is the most modern block in Beijing, in view of the steel structure housing has the above advantages, as the only high-end apartment on the financial street, in order to create a more comfortable sense of space and more energy saving, Jin Chen Apartment has been designed into a high-grade steel structure housing, and was named Beijing's first residential steel structure system demonstration project after the announcement of the outline. It is also the only small high-rise steel structure residential project in Beijing.

Basics

The increase in steel products and construction steel varieties has laid a good foundation for the development of steel structures. China from 1996 steel production exceeded 100 million tons, has become the world's steel power, with the country in the 21st century to pay close attention to metallurgical science and technology progress, improve the technical level of China's steel industry and assembly level, by 2020 China is expected to become the world's steel power. H-shaped steel, which could not be produced for a long time in the past, can now be produced in "Masteel", "Laisteel" and the first rolling mill in Anshan. The maximum cross-section of H-shaped steel has reached 700mm, the annual production capacity can reach 1.4 million tons, the annual production capacity of color steel plates for light steel structures has reached 700-900,000 tons, and the annual production capacity of cold-formed steel is about 1.2 million tons. This laid the foundation for the development of steel structure buildings. The development goal of building steel structure during the "Tenth Five-Year Plan" period is to strive to achieve the annual construction steel structure steel accounted for 3% of the country's total steel production. The development goal of building steel structure in 2015 is to strive for the annual national building steel structure steel volume to reach 6% of the total steel. Thus, the development of China's construction steel structure will be on a new level. Efficient welding process and application of new welding and cutting equipment. For example, the double-sided forming single wire and multi-wire submerged arc welding of various reverse liner methods, the double-sided double-wire rapid welding production lines of the gantry I-beam, various CNC flame machines and laser cutting machines, create good conditions for the efficient production and production of high-quality products for steel structures. The use of high-efficiency welding materials, such as gas shielded welding and self-protected flux-cored wire and various high-efficiency welding rods, will account for about 40% of the total production of welding materials by 2005; Friction type strong bolts and the use of automatic torque control methods and anti-corrosion, fire prevention and other new technology, the development of new materials have created good conditions for the in-depth development of steel structure engineering.

Development mode

Energy saving, high efficiency, environmental protection and industrialization. In the last few years of the 20th century, China's urban housing construction with an annual completion area of 440 million square meters, the total output value of 600 billion yuan (about 9% of GDP), the construction of rapid development, housing industry has become a new growth point of the national economy in the new century. To realize the modernization of the housing industry and solve the problems in the housing construction, such as low level of industrialization, low rate of parts, low grade of residential materials, low life, high energy consumption of solid clay bricks, which is not conducive to environmental protection, has been listed as an urgent problem to be solved in the new century. China's construction industry requires the whole industry to study the new system of steel structure application in all kinds of buildings, expand its application scope, and develop multi-storey steel structure buildings. Internationally, American designers and structural engineers attach great importance to the study of metal structures and their durability, practicality and economy, and European experts have proposed that steel structures have the conditions of green buildings, that is, buildings that are conducive to protecting the environment and saving energy. They believe that metal structure buildings have a good sense of space, can achieve innovative planning and space design, architecture, not only living, use, but also consider creating a more comfortable space for people, saving energy space. Japan produced 59 million tons of steel in 1998, and the amount of steel used in building structures accounted for 13%, while the steel structure of residential buildings accounted for a considerable proportion of the steel used in building structures, and Hong Kong is more high-rise buildings everywhere. Taiwan earthquake, it is obvious that steel structure building is better than reinforced concrete building; From the point of view of the earthquake damage, the general multi-storey housing basically all collapsed to the ground, and the steel structure of the housing did not collapse, so the Taiwan authorities require that the multi-storey housing construction must use steel structure. China's multi-storey residential and small high-rise residential steel structure pilot, starting from Tianjin. Tianjin adopted three different structures, different wall materials, and different construction methods. Pilot projects covering more than 200,000 square meters will be launched. The first is the structure form of square concrete-filled steel tube column with large space; The second adopts steel truss structure form; The third is concrete-filled steel tube structure. The square meter steel used in the three structures is less than the steel used in the reinforced concrete structure. Qingdao, Shanghai and Xinjiang have listed a certain area of housing projects for pilot. Because China's "steel housing" has just started, many structures can not be mass-produced, therefore, steel structures will be more expensive than concrete structures. The construction unit of Beijing Jin Chen Apartment calculated that although the overall price of steel structure is relatively high, but due to the short construction period, low energy consumption, high utilization rate, and improved quality grade, the comprehensive cost is not high. At the same time, because this is the first steel structure residential demonstration project in Beijing, suppliers provide steel structure parts at the most favorable price. The total cost is similar to the concrete structure.