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Wood frame structure is the most popular structure system in North America. In North America, wood frame structure has a history of more than 100 years. In most parts of the United States and Canada, we can still find civil and commercial buildings built more than 100 years ago today. According to statistics, in 1997, about 1.138 million new single villa buildings were built in the United States, 90% of which were built with wood structure. In addition, the vast majority of 338000 multi-storey houses were built with wood structure.
In recent years, the new concept of green environmental protection and energy conservation has been vigorously advocated in China's construction field, and wood frame structure has been well developed by virtue of its own advantages. In early 2004, the Ministry of construction of China and the General Administration of quality supervision, inspection and Quarantine issued the code for design of wood structure (gb50005-2003), which provides the basis for design of wood structure in China.
Wood structure has the following advantages:
·The construction period is short. The construction period of wood structure house is about 1 / 2 of that of traditional house. The construction period of traditional house is 6-10 months, while the construction period of wood structure house is 3-4 months, which greatly shortens the time for developers to withdraw funds and reduces the operation cost. When the traditional house is completed, it is only a rough house, while the wooden house structure is basically finished with decoration, so it only needs personalized decoration to move in.
·Diversified design style, interior layout and decoration flexibility. Wood structure not only applies to a wide range of external architectural styles, but also provides a considerable degree of freedom in interior layout and decoration, which can give full play to the imagination of designers and meet the individual needs of consumers.
·Heat preservation and sound insulation, energy saving. Wood is a good electrical insulator with low conductivity. In addition, wood structure uses the principle of sandwich heat preservation and air barrier, which makes wood structure have good heat preservation and heat insulation performance, less energy consumption, and greatly saves energy cost for consumers. The results show that the thermal insulation performance of 150 mm thick wood wall is equivalent to 610 mm thick brick wall. Compared with brick concrete structure, wood structure can save 50-70% energy (5-8% higher room yield). The gypsum board installed on the wall and ceiling, as well as the thermal insulation materials placed in the floor and wall, can well reduce the sound transmission.
·Fire protection is up to standard. For light wood structure, fire-resistant gypsum board is used as the protective layer of wood structure to achieve a fire resistance rating of 1 to 2 hours; for medium-sized wood structure, the carbonization effect of wood can be used; when wood is burned, a carbonization layer will be formed on the surface, and its low thermal conductivity can effectively prevent the external flame from spreading inward, so as to ensure that the whole structure will not be damaged in a short time (steel structure in case of fire The steel beam will be rapidly heated, softened and dropped, resulting in dangerous consequences).
·The earthquake resistance is the best. Wood structure has very high strength - light weight, high toughness, strong resistance to instantaneous impact load and periodic fatigue failure, and has the best seismic performance in all structures, which has been fully proved in many large earthquake areas. In 1995, the Kobe earthquake in Japan, wood structure because of its own advantages, resulting in little harm, which is one of the reasons for the rapid development of wood structure in Japan.
·There is no water condensation. In areas with distinct seasons or large temperature difference between cold and hot, the steel structure will produce condensation steam due to the internal and external temperature difference, so that the water will corrode other insulation layers and other materials. Over time, it will have a bad impact on the whole structure. This is also one of the reasons why the United States, Japan and other developed countries rarely use steel structure as residential housing, while the wood structure does not have this hidden danger. The balance of wood structure itself is worried about other structures. After treatment, the physical properties of wood are stable, and it will not easily deform or react with chemicals.
·Moth and moth proof. The modern wood structure houses are protected from termites by cleaning the site, using the barrier system, and using the chemical pressure anti-corrosion treatment materials in the contact with the soil. The experiment shows that the building materials treated by pressure anticorrosion can resist termite erosion for a long time.
·Clean and safe construction. Compared with the steel structure, the construction period of wood structure is short, the construction is clean and simple, there is no waste water, iron scraps and other construction wastes, and there is no big noise, which will not cause much impact on the surrounding environment. No electric welding operation, relatively safe.
·Green environmental protection, comfortable living. Wood is the only renewable building material. Wood structure houses do not pollute the environment in the process of construction. The natural affinity of wood structure houses is beneficial to the health of residents, which is incomparable to other structure houses, and is also strongly advocated by China and other countries around the world.