Steel structure is divided into construction steel structure, bridge steel structure, compared with the reinforced concrete structure is widely used at present in building field, has the advantages of high strength, light weight, low construction cost, short construction period and manufacturing advantages, so many advantages are widely attention and quick development, the use of steel structure into widespread use steel structure from the major engineering, iconic, showing a thriving scene has never been.
A steel structure, application status
The heavy steel structure 1 high-rise
High-rise steel structure building is often regarded as a city landmark. Since the 80's have been built and the high-rise steel structure more than 100 buildings, a total area of about 8000000 square meters, the amount of steel about 800000 tons.
Beijing, Shanghai under construction and newly built high-rise steel structure building reached more than 10. Such as: Shanghai Center Tower (built in, 632 meters), the Shanghai World Financial Center (101 floors, 492 meters high, steel capacity of 65000 tons); Beijing TV Center (construction area of 183000 square meters, height of 41 layers, 227.05m, steel capacity of 38000 tons); China World Trade Center Center of the three period (construction area of 540000 square meters, height 330m); the new CCTV building (such as a building area of 50000 square meters, height 234m, weight of steel 128000 tons). 200-300 million square meters of high-rise steel structure construction in China every year, about 450000 tons of steel consumption.
2 large span space steel structure
In recent years, the spatial structure in a grid and shell as the representative of a large number of development not only continue, used in the civil construction, but also for industrial plants, warehouses, terminals, gymnasium, exhibition center, Grand Theater, museum, etc.. Industrial workshop steel structure with large amount of such as steel base in Caofeidian, Shanghai Jiangnan Shipbuilding Base, representative venues such as the 2008 Beijing Olympic National Stadium (Hall), 2010 Shanghai World Expo venue (the amount of steel structure of about 300000 tons), 2010 Asian Games (Guangzhou), Ji'nan National Games, Universiade in Shenzhen and the Nanyang national peasant movement will build the city stadium. According to the China Steel Structure Association Branch of Statistics: the spatial structure of grid and shell production in recent years has been in the trend stationary state, every year 1500, about 2500000 square meters, with about 70000 tons of steel, steel structure the steel present characteristics of varieties, specifications of complex, large dosage, high strength, the main varieties are: Q235C, Q345C, 390D (for pile underground embedded), Q345GJ, Q420, Q460 etc..
With the promotion of research and development of deep drawing structure of suspension and the film Zhang and engineering application. Prestressed space structure has applied. Hangzhou pagoda, Hainan Millennium Tower, Guangzhou new TV Tower (610 meters high, steel capacity of 40000 tons) and Kunming Expo Park Art Square membrane structure such as a large number of new steel structure buildings and structures are constantly emerging. Cable and membrane structure is currently in the development stage, small amount of domestic membrane structure engineering company, design and construction to undertake many stadiums, airports, parks and street landscape. The current high school block membrane materials still need to import (PTFE, ETFE).
3 light steel structure
Light steel structure is relative to the heavy steel structure, the types of portal frame, corrugated steel arch roof structure, mainly used for light industrial plant cotton and grain warehouse, wharf and bonded warehouse, agricultural products, building materials, furniture and other types of trading market, stadiums, exhibition halls and housing activity, add layer architecture etc.. The amount of steel in general 30-40kg / square meters or so (not including the reinforcements dosage). The annual new lightweight steel housing 8000000 square meters, about 200000 tons of steel.
4 steel - concrete composite structure
Steel - concrete composite structure is to give full play to their respective advantages of steel and concrete, the reasonable combination of two kinds of materials, not only has excellent static and dynamic performance, work, but also can save lots of steel, reduce project cost and accelerate the construction progress, less pollution to the environment, in line with the development direction of building structure in china. In China's development is very rapid, has been widely used in metallurgy, shipbuilding, electric power, transportation and other sectors of the construction, and the rapid momentum into the bridge engineering and high-rise and super high-rise buildings.
In the high-rise buildings, built by all the composite structure of the high-rise building -- Shenzhen Saige square building, high 291.6m, is the world's highest steel - concrete composite structure. Have been built across the country by the combined structure of high-rise buildings more than 40 buildings of. Combined structure of arch bridge has been completed and has been more than 300 seat.
5 steel structure residence
Constructed of steel structure residence weight of reinforced concrete residential is about 1/2, which can meet the demand of residential large standard width of a room, the use of the area ratio of the reinforced concrete residential increase about 4%. The steel can be recycled, construction and demolition of the environmental pollution is less, conforms to promote the industrialization of residential development of energy-efficient type of residential national policy.
China is now the largest construction market, the average annual housing construction of about 2000000000 square meters (2009 housing construction area of 3200000000 square meters), which the steel is about 2-3%, the vast majority are reinforced concrete structure and brick concrete structure, and a small amount of timber structure, brick structure and adobe house. Nearly 800000000 square meters / year of urban residential so. Steel structure building in our country the construction industry accounted for less than 5%, and the developed countries has reached more than 50%, the potential development space steel structure residence is very big. At present, in Beijing, Shanghai, Tianjin, Hebei, Wuhan, Qingdao to build a low layer, multilayer structure, Gao Cenggang residential pilot demonstration project, has built about 5000000 square meters, with about 200000 of t steel. Baosteel invested large amounts of funds and researchers in the industrialization of steel structure residence, in Wuhan, Shenyang and other places of design and construction of multiple steel structure residential project demonstration, built in 2007 to steel structure residential projects -- cyber Park demonstration of affordable housing in the area of Wuhan Hanyang District, up to the requirements of the World Steel Association about "international civil construction steel project" technology. In addition, according to the Sichuan earthquake disaster area to provide as a transitional period of resettlement housing more than 60 sets of housing activity, Baosteel completed a pilot project board material utilization.
6 bridge steel structure
Each big city will bridge the traffic infrastructure construction as an important basis for economic development. The use of steel structure are the main part of the cable-stayed bridge, steel box, cable, tower, big bridge 600 meters above for the steel structure bridge? "Eleven five" three years before the average new bridge 30000 / year, the average annual steel capacity of 13000000 tons. According to statistics, the implementation of the switch to steel structure bridge 3480 is currently under construction of highway concrete bridge, switch to the steel structure will be a net increase of 5460000 tons of steel consumption. By the end of 2008, the country's 590000 bridge bridge steel structure is less than 1%. With 600000 bridges of steel structure bridge American accounted for 33%, Japan 130000 bridge steel structure bridge compared to the larger gap accounted for 41%. Chinese first full steel structure tower bridge is the Nanjing bridge, the amount of steel pylon with only reached 14400 tons? Stonecutters bridge in Hongkong (1018 meters long) and the Su Tongchang River Bridge (1088 meters long) to occupy the world's largest cable-stayed bridge in the top two, to 2015, Chinese to build 5 Cross Strait Bridge the total amount of steel, 6250000 tons.
Two, steel structure industry gaps and future trends
At present, the industry of steel structure in our country steel accounted for only about 4% of the total amount of steel across the country, there is a big gap with developed countries is about 10% percentage. The domestic steel products can basically meet the needs of steel structure processing, but with foreign countries than there are gaps in the specific variety of specifications and performance, such as high strength large size ultra thick H steel, high strength ultra thick plate etc.. At present, Japan in the building, promotion of the use of strength grade Q690 steel bridge, and has been mature by Q960 machinery steel.
The steel structure development and constantly promote the development of high performance steel, is currently in the revision of national standard "steel structure design specification", Q390, Q420, Q460 will included in the specification, long-term changes to Q235, Q345 as the main structural steel situation.
The output of steel structure in China is about 23000000 tons, the output value of more than 300000000000 yuan, the total amount of steel structure will keep the 9%-10% annual growth rate, to 2015, achieve doubled, to reach 5000-6500 million tons, accounting for 10% of the national total production of crude steel, steel structure building construction of total housing accounted for about 15-20%.
A period in the future, the domestic steel varieties, specifications, quality not only to meet the needs of domestic and international steel structure development, pertaining to the field of application and development of high performance steel international leading; steel structure products, accessories and ancillary product technology reached the international advanced level. Highlight the large volume, the proportion of output value in the industry to highlight the status of the steel structure housing, bridge steel structure and non - standard, complete sets of equipment manufacturing (including new energy wind power, nuclear power, smart grid, three steel structure net ocean engineering, sea) potential market for technology development and independent innovation, promote the comprehensive improve the construction quality of steel structure housing, improve the building use period and the actual life is more advanced, improve related products, parts of the perfect, and gradually make the steel structure industry has become China's strategic emerging industry, iron and steel, steel structure has the preliminary power target.
