In the next decade will be the time for world steel industry structure adjust the pattern and further development and also critical period for China achieve the big and powerfull country of steel structure ,
when the Enterprises in the expansion of the scale , also should pay more attention to improve the control and technology innovation ability and adhere to the scientific outlook on development as guidance, transformation of the mode of development and expansion of field of vision, and promote China’s steel structure industry sustained, healthy and rapid development.
Our country should pay attention to the develop of steel structure
The development of steel structure should rise to the national strategy ,At present, the development of China’s steel structure industry is at the critical period, our country should continue to increase efforts to support the steel structure industry to increase R & D investment, stepping up the introduction of the implementation of tax and financial incentives to encourage and promote the steel structure building , strongly advocated in schools, hospitals, airports, railway stations, sports stadiums with steel structure and including the these building projects in the national reserve plans.
Our government give the opportunity to more steel structure related institutions and enterprises to display their abilities, so a lots of enterprises could participate in the construction of various types of steel structure ,
Steel Structure industry including the design and construction ,the design of steel structure in first , the key of steel structure design Steel structure design is the key to the correctly select the structure scheme , only select the correct structure scheme, they can better reflect the energy saving, material saving, economic, applicable, beautiful, and many other advantages of steel structure ,
Currently, a lot of steel structure building projects in China use foreign design ,where the structure of the many projects designed not to reasonable, which cause large amount of steel,much costly and a lots of trouble during installation .
The design of steel structure should follow the philosophy of less cost multi-use, with minimal configuration provides maximum structural bearing capacity,the designer use reasonable of steel as the display the highest design level,In the face of fierce international competition, to strengthen the overall design ability, including the introduction of international design team, the promotion enterprise’s design strength is particularly important.
Therefore, we should have international thinking, international perspective, international perspective. We hope that the country can set up as soon as possible with a world-class steel and Design Institute , in order to meet the needs of our steel structure industry, the rapid development of the green, low-carbon, saving steel structure design philosophy in the whole process of design.
In China the fire protection of steel structures mainly used fire retardant coating,foam fire retardant paint or outside coated Fire-proof layer and other method , For the exposed steel structure, such as stairs used Coating and paint ,using 10 ~ 40mm thick paint, fire resistance of up to 1.5 ~ 3h, and foam paint fire-resistant time is generally 0.5h ,for the hidden steel structure, perlite and vermiculite fireproof coating or fire prevention board is economic and effective method, 30 ~ 40 mm thick coating can achieve the fire resistance of 1.5 h and corrosion prevention.
The exposed steel structure commonly used corrosion resistant coating or paint, including the primer and topcoat , the anti-corrosion coating is valid for 10 to 20 years,galvanized steel deck itself has certain corrosion resistance, when used in floor anti-corrosion problems can be solved with the aid of fire-retardant coating, but even when used in roof and wall of coated with organic coating, increase its using life .
Multi-storey light steel structurebuilding fire and corrosion protection measures:
Multi-storey light steel structure building floor must have sufficient capacity, stiffness and integrity. using pressure plate laying on the beam, and then pouring 100 ~ 150mm concrete slab, that is profiled sheeting-concrete composite slab ,pressure plate and steel beams connected with pegs ,It may also be added with prestressed concrete thin layer or cast reinforced concrete floor , it should ensure reliable connection between floor and steel beams ,Consider the combination of the steel beam and slab design such as function, can significantly increase the bearing capacity of the beam and the overall stability, and effectively reduce the size of beam.
When connecting the main beam and secondary beams are generally simply supported contour connection sometimes made without high connections, such as the use of pressure plate combination floor, in order to facilitate the laying of the pressure plate, the top surface of the primary and secondary beams differential pressure type plate thickness , but also can increase the net height of the storey building.
Roofing system of multi-storey light steel structure Building
For multi-storey light steel structure building, traditional linoleum and asphalt roofing waterproof layer is not economic, now mostly use waterproof coiled material , Roof also gave up the traditional cement mortar screed-coat and cinder insulation layer, and the use of lightweight thermal insulation material, such as JQN board, polyethylene concrete board, etc.can make according to the variable thickness and cancel the roofing leveling layer. multi-storey light steel structure building foundation usually used under column independent foundation, strip foundation, cross foundation, sometimes raft foundation may be adopted.
when used under column independent foundation should attention to the relative uneven settlement of the foundation, foundation beams commonly used of cast-in-place or precast reinforced concrete structures,sometimes also can adopt steel base beam according to the requirement, but usually will be buried in the ground concrete column foot and steel beam outside coated concrete to solve the problem of corrosion.
Envelope of multi-layer light steel structure building
In order to reduce the weight of the multilayer light steel housing, building envelope more use of lightweight materials. Multi-wall facades made of lightweight filler material, such as hollow blocks, aerated concrete, and sometimes can be composite wall steel sheeting plus lightweight insulation layers, there are many beautiful houses facades made of lightweight glass facade structure. Lightweight infilled walls within walls can be hollow blocks, aerated concrete or light steel keel gypsum board, at present there is also an aluminum frame and glass partition.
Detail Connection of multi-layer light steel structure building
Multi-storey light steel structure building column usually used welding H shape or box sections. Because of H-section beam with thinner web plate , so the weak axis direction and the connection of beam is used more articulated, and strong axis adopt just answer form. Sometimes also can adopt semi-rigid connections, but its mechanical characteristics is complex, often through experiment to obtain more accurate design data. At the same time of multistoried building steel structure components are relatively thin, avoid site weld connection. In order to strengthen the overall structure stiffness, can the second beam to make the form of a continuous beam.