Main technical content of steel structure:

      (1) High rise steel structure technology.According to the building height and design requirements, the frame, frame support, tube and mega frame structure are used respectively, and the components can be steel, reinforced concrete or concrete-filled steel tube.The steel members have good light ductility, and can be welded or rolled steel, which is suitable for ultra-high buildings; the reinforced concrete members with high rigidity and good fire resistance are suitable for medium and high-rise buildings or substructures; the concrete-filled steel tube construction is simple, which is only used for column structures.

      (2) Space steel structure technology.The space steel structure has the advantages of light self weight, large rigidity, beautiful shape and fast construction speed.The spherical joint plate grid, multi-layer variable cross section grid and grid shell with steel tube as member are the structural types with large amount of space steel structure in China.It has the advantages of large space rigidity and low steel consumption. It can provide complete CAD in design, construction and inspection procedures.In addition to the grid structure, the spatial structure still has long-span suspension structure, cable membrane structure and so on.

      (3) Light steel structure technology.Along with the light color steel plate made of wall and roof enclosure structure of the new structure form.The light steel structure system is composed of large section thin-walled H-shaped steel wall beam and roof purlin welded or rolled by more than 5mm steel plate, flexible support system made of round steel and high-strength bolt connection. The column spacing can be from 6m to 9m, the span can be 30 m or more, the height can be up to 10 meters, and light crane four can be set.The steel consumption is 20-30kg / m2.At present, there are standardized design procedures and specialized production enterprises, with good product quality, fast installation speed, light weight, less investment, no seasonal restrictions on construction, which are suitable for various light industrial plants.

      (4) Steel concrete composite structure technology.The load-bearing structure of beam and column, which is composed of steel or steel management and concrete components, is a steel-concrete composite structure. In recent years, its application scope is expanding day by day.The composite structure has the advantages of both steel and concrete. The overall strength is large, the rigidity is good, and the seismic performance is good.Generally, the steel consumption of composite structural members can be reduced by 15-20%.Composite floor and concrete-filled steel tubular members also have the advantages of less formwork or no formwork, convenient and fast construction, and great potential for promotion.It is suitable for frame beams, columns and floors of multi-storey or high-rise buildings with large load, industrial building columns and floors, etc.

       (5) High strength bolt connection and welding technology.High strength bolt transfers stress through friction, which is composed of bolt, nut and washer.High strength bolt connection has the advantages of simple construction, flexible removal, high bearing capacity, good fatigue resistance, self-locking and high safety. It has replaced riveting and partial welding in the project and become the main connection means in the production and installation of steel structure.For the steel members manufactured in the workshop, the thick plate shall adopt automatic multi wire arc submerged welding, and the box column diaphragm shall adopt the welding technology such as melting tip electroslag welding.Semi automatic welding technology, gas shielded flux cored wire and self shielded flux cored wire technology shall be adopted in the field installation and construction.

       (6) Steel structure protection technology.The protection of steel structure includes fire protection, corrosion protection and rust prevention. Generally, it is not necessary to conduct rust prevention treatment after the treatment of fire retardant coating, but it is still necessary to conduct corrosion prevention treatment in buildings with corrosive gas.There are many kinds of fireproof coatings in China, such as TN series, mc-10, etc., among which mc-10 fireproof coatings include alkyd enamel paint, chlorinated rubber paint, fluororubber paint and chlorosulfon a ted paint.In the construction, appropriate coating and coating thickness shall be selected according to the steel structure type, fire resistance rating requirements and environmental requirements.