Why are prefabricated buildings of light steel the best for characteristic town and ecological manor?
Author： Date：2017-12-30 From： Hits：14
First, an overview
█ With the basic characteristics of
The cold-formed thin-walled steel members are taken as the basic structural skeleton, and the new structural plank as the structural system, with other thermal insulation and decoration materials, and the building construction system integrated by factory and on-site assembly.
The system uses the cold-formed steel structure, has the characteristics of small size of section, light self weight, increased by 5 to 10% compared with the traditional building area, significantly reducing the cost base; load-bearing system unique architectural style, the rich light movement, improve indoor layout flexibility; low carbon environment-friendly building materials the construction, durability, structure safety, with the earthquake, fire, thermal and sound insulation performance is good, is a kind of efficient energy-saving green building system.
█ The scope for
Ultra light steel residential system suitable for 1 to 6 layers (excluding basement, eaves height should be no more than 12m) construction, renovation and expansion of buildings. But the number of structures of the mixed structure of cold - formed thin - walled steel frame and steel structure and reinforced concrete structure is not limited by this limit.
Two. Performance indicators
Durability: more than 70 years of service life;
Snow resistant performance: basic snow pressure 1.55kN/ square meters;
Seismic performance: 9 degree fortification (basic earthquake acceleration 0.4g);
Wind resistance: basic wind pressure 0.85kN/ square meters, 209km/hr wind speed
Sound insulation performance: the sound insulation of outer wall sound insulation (200mm thick wall) is 65dB, and the inner wall (double-layer double layer 9.5mm plasterboard, 181mm wall) is 44dB;
Ventilation performance: the combination of natural ventilation and air supply ensures that the indoor air is clean and clean, and the new air volume is more than 15%.
The impact resistance of the exterior wall: the concentrated impact load of 250kg;
Insulation resistance: 200mm thick wall is 4.24K - /W square meters, its insulation performance is 2 times that of 490mm thick porous brick.
Three. Normative reference files
The following standard provisions are quoted. When the standard is revised, the reference standard of the latest version is used:
"Code for building structure load" GB50009-2012
"Code for design of concrete structure" GB50010-2010
"Code for aseismic design of buildings" GBSOOll-2010
"Code for fire protection of architectural design" GB50016-2014
"Code for design of steel structure" GB50017-2003
"Code for design of cold formed thin-walled steel structure" GB50018-2002
"Unified standard for design of reliability of building structure" GB50068-2001
"Technical specification for low level cold-formed thin-walled steel buildings" JGJ227-2011
"Cement fiber flat" JC/T412.1-2006
"Fiber reinforced calcium silicate board" JC/T564.1-2008
"Standard for acceptance of quality of construction of steel structure engineering" GB50205-2001
Carbon structural steel GB/T700-2006
"Technical conditions for cold bending steel" GB6725-2008
"Low alloy and high strength structural steel" GB/T1591-2008
"Quality inspection and evaluation standard for steel structure engineering" GB50221-2001
The current relevant technical specifications and regulations of other countries or industries.
Four, the seven advantages of the light steel housing system
█ For safety
Compared with wood structure, the fireproof performance and anti termite performance of steel structure are much better than that of wood structure building. The emergence and development of ultra light steel structure in North America is mainly due to the poor fire protection performance and termite resistance of wood structure. Therefore, ultra light steel structure system has been developed on the basis of light wood structure.
Compared with the traditional brick concrete structure, the steel structure system itself has more ductility and elasticity than the brick concrete structure. Ultra light steel structure system belongs to the plate rib structure, which is formed by the light steel keel and Ousong board wall and floor as a load-bearing structure, which belongs to statically indeterminate structure, not destroy single light steel keel or Ousong board immediately lead to the overall structural damage, is conducive to building evacuation. At the same time, light weight steel structure is more favorable for resisting horizontal load when earthquake. The horizontal load is the product of the self weight and horizontal acceleration of the building, and the smaller the building the smaller the load is, the smaller the horizontal load is. Therefore, in Japan and Taiwan, where there are many earthquakes, the lower buildings are mostly light wood and steel structures with lighter weight.
█ For convenience
Compared with the traditional brick concrete structure, the transportation of steel structure with light weight is less than that of brick concrete structure. It is conducive to the construction of areas where transportation is inconvenient, such as islands and mountains. Ultra light steel building can also complete partial assembly work in factories according to the needs of the project, form a whole wall and floor, reduce field workload and speed up on-site installation, which is suitable for projects with poor construction conditions and short construction period.
█ For environmental protection
Light gauge steel residential system products used in the building materials are green environmental protection material to meet the national standards, the use of light steel keel after 70 years can be recycled, the scene in the process of the construction of the extensive use of finished product component installation, construction of water demand, the whole construction process than brick structure greatly reduces the waste water, waste dust and solid waste emissions to protect the local environment. The material loss of the light steel housing system is reduced by 60%, the waste in the field is reduced by 80%, the recoverable material is 80%, and the energy saving of the building is raised by 50%.
█ For energy saving
The outer wall of light steel residence system is a double-layer thermal insulation structure. It is composed of gypsum board, light steel keel, R19 centrifugal glass fiber cotton, OSB (Ou Songban), breathing paper, Extrusion board and exterior wall facing layer from inside to outside. Because the wall adopts R19 centrifugal glass fiber cotton and 25mm thick board double insulation material, thermal insulation wall system for 4.24K value can reach /W square meters, its insulation performance is 2 times that of 490mm thick porous brick wall.
Building roofs from inside to outside are: plasterboard, R30 centrifuge glass fiber cotton, light steel keel, OSB (oozing plate), waterproof roll and roof decoration. Bargeboard porous structure, the roof ventilation ventilation, air circulation can mold can also play a role in insulation, the entire roof system is 5.284K - /W thermal resistance value is 120mm square meters, thick concrete roof (thermal resistance value of 0.07K - /W square meters) 75 times.
█ For practical
The thickness of the double layer thermal insulation decoration of the light steel housing system is only 180mm, which is smaller than that of the masonry wall (generally 240mm) that does not contain the heat preservation decoration.
According to the calculation of the project, the housing rate of the light steel housing system should be increased by 5%-10% than that of the ordinary brick concrete structure. At the same time as the beam column steel structure by the wall and floor stress rather than the traditional force, so the light steel building indoor almost without Liang pillar, higher space utilization.
█ For fast
The light steel housing system adopts the factory components, and does not need maintenance, so the construction speed is improved by 30%-50% than that of the ordinary brick concrete structure. The whole construction process is divided into eight steps: foundation construction, wall installation, roof installation, structural seal plate, exterior wall insulation, interior decoration, outdoor decoration and completion. The construction period of the blank room without foundation construction is 1-2 months, and the construction period of the intensive repair room is 2-3 months.
A set of 100 square meters of super light steel structure installation time is only 4-5 days, the overall construction period is less than 1/2 time of the traditional construction.
█ With good comprehensive economic benefits
A. construction cycle is short, early production early benefit;
B. Increased effective use of the area;
C. investment is allocated reasonably, its value is worth, and the ground and underground engineering fees are allocated 90:10;
D. materials and labor cost allocation 60:40;
Therefore, the comprehensive economic benefit of the light steel housing system is better than that of the reinforced concrete structure.
