China’s total construction steel accounts for about 20% ~ 25% of all steel production, developed countries accounted for more than 30%. Such as the United States and Japan, the indicators have been more than 50%. In our country,
the steel is mainly used in construction steel structure in construction, reinforced concrete with steel bar, steel wire, steel wire, doors and Windows, etc., of which accounts for only around 10%, one hundred million tons of steel
production only 200 ~ 3 million tons used for steel structure in China .

According to some data from the US metal building industry , the development and the basic situation of the United States of metal construction industry: in the 20th century, 50,60, 70,80 and 90 years, with annual sales in millions
of dollars of / in tons In terms of processing capacity was 150 / 30,300 / 65,1200 / 110,1500 / 125 and 2200/190. As can be seen, the United States, sales increased rapidly with a metal building, estimated to now more than 2.5 billion
US dollars, the annual processing capacity has reached more than 2 million tons.

Large-span steel structure
Large span and more large span mainly used steel structure or “membrane”, but the inflatable membrane due to some disadvantages is seldom used in recent years, the tension membrane is also needs the support of wire rope and steel rod.
Large-span steel structure used for multi-purpose stadiums, convention and exhibition center, exhibition hall, lounge, hangars, etc. The earliest largest flat truss span is the 1960s American University of California, Los Angeles Coliseum (91m × 122m Pyramid). Shell is the largest double network in the 1970s in the United States built the dome universe Houston (Astrodome, diameter 196m) and the New Orleans Superdome (Superdome, diameter 207m). 1990s in Nagoya, Japan has built the world’s largest single-span reticulated shell construction diameter 229.6m, structure diameter 187.2m, with three to grid node is able to withstand the axial force and moment rigidity node. The world’s largest indoor stadium in the United States 1996 Olympic main stadium Atlanta Stadium (quasi-elliptic plane, 186m × 235m), uses a roof tensegrity system, mainly by cable, rod, film composition, is the most promising a new spatial structure. Fukuoka, Japan, in 1993 built the stadium, the diameter of 222m, is today the largest steel roof opening and closing, leaving in 1989 to build the Toronto Sky Dome (Skydome, diameter 203m) down to the second span of the opening and closing of the world’s largest structure. 300m over the entire roof structure using steel plate and steel composition is not the optimal solution, recent studies are more successful hybrid (mixed) structure, that rod, cable, membrane mix.

The most typical project is the Millennium Dome (TheMilleniumDome) at the turn of the century, the museum is located in the south bank of the Thames in Greenwich, London, UK, is the world’s largest span roof, dome cool like a flying saucer, diameter 320m. Of course, from a theoretical perspective, and then a big span structure is possible to achieve, can be achieved in reality should be further studied, but in terms of the bridge, 1000m or so span has been achieved, the longest span cable-stayed bridge in the world The Tatara Bridge in Japan (total length 890m); Japan’s largest suspension bridge in the name of the Stone Bridge (1991m), the largest highway and railway dual-span bridge in Hong Kong’s Tsing Ma Bridge (suspension 1377m). The world’s first suspension hyperbolic paraboloid roof is a famous American mine in athletics hall.
Lower-level, multi-storey steel structure building and light steel structure
American Metal Building industry mainly distributed Industrial (production plants, warehouses and auxiliary facilities, etc.), commercial (shopping malls, hotels, exhibition halls, hospitals, office buildings, etc.), community (private and public buildings such as community centers and schools, stadiums, libraries, churches, etc.), and other aspects of the comprehensive, respectively, accounted for 46%, 31%, 14% and 9% share.

In the United States, the low-rise buildings used steel structure is very common ,the low-rise buildings which height lower than 18m , the number of story not more than five layers of workshop, warehouses, offices and other buildings, such as office and community.
High-rise and super high-rise steel structure buildingd due to the continuous improvement of human cultural life of the high-level, long-span construction requirements will be higher. The steel itself with light weight, high strength, fast construction and other unique advantages, so the high-level, long-span, especially the super-tall, large span steel structure is ideal. Currently the world’s tallest, the biggest structure are used in steel structure
and the venue of the Olympic Games to use steel structure. The world has built several pure steel building is the world’s tallest high-rise building currently.
They are:1931 built 102 floors, high 381m of the Empire State Building in New York; 1969 completed 110-story, 417m of the New York World Trade Center (the North-South two); in 1970 completed the 110-story, high-443m of Chicago Sears Adams House; 1996 built 450m high building and other petroleum Malaysia Twin Towers.

Light steel construction in some developed countries has been widely used in factories, warehouses, stadiums, exhibition halls, supermarkets and other buildings. Light steel structure is single color sheet used as wall and roof ,light-gauge steel used as purlin , welding H section as main beam , connected by bolt , welding or jointed
portal frame is the mainly building structure which together with parts, fasteners, doors and windows of the building to form a more perfect system, that light steel structure system. The system is fabricated in factory , on-site assemble. With light weight, short construction period, adaptable, beautiful appearance, low cost, easy maintenance.
Giant steel structure for top or super-tall building a new system, it is in order to satisfy the special function or comprehensive function. It has good adaptability and potential efficient structure performance is a development of the structure.
In addition, the Olympic Games, fairs and so can show the level of development of steel structures. As in 1972 in Munich, Germany (covering 74,800 m2 stadium cable net buildings), 1976 Montreal, Canada, 1980 Moscow, 1984 Los Angeles, 1988 Seoul, Korea (120m diameter and 93m in diameter gym are cable dome Fencing ), 1992 Barcelona, ??Spain to St. Joe Stadium (128m), 1996 US Atlanta Georgia Dome (186m × 235m cable dome), the main stadium in Sydney, Australia in 2000 (11 million, two 220m × 70m of hyperbolic paraboloid shells network ).
At present, the international community and our country in a popular wavy surfaces, as well as three-dimensional truss system supporting the tree directly intersection intersecting nodes. Looks magnificent and beautiful. Our Shenzhen Airport, Beijing Capital International Airport, Shanghai Pudong International Airport is a typical example.
Airport and hangar are all long-span structures are basically in engineering steel structure. Such as London Heathrow hangar (one, two) should be relatively large-scale projects. In recent years, the capital of China, built hangar (2-153m × 90m) uses three diagonal square pyramid grid node plate solder ball grid, its large-scale span, is among the best in the world. Airports steel roof on the building due to the requirements of relatively high, it is colorful. Hong Kong International Airport, Malaysia Airports are using a large area single network shell form.