Prefabricated architecture is a new architectural pattern symbol appearing in the construction market. This paper systematically introduces the development of prefabricated buildings in recent years, mainly discusses the advantages, construction difficulties, key construction technologies and technological processes of prefabricated buildings, and points out that prefabricated buildings are an important breakthrough field in the future construction industry, and the long-term, sustained and rapid development of the construction market can be promoted through the improvement of the technical level and large-scale development of prefabricated buildings.
The construction market is an important part of the national economy and is of great significance to the stable development of the national economy. During the "Twelfth Five-Year Plan" period, China's GDP grew at an average annual rate of about 7%, and the construction market economy also maintained a high growth rate. The rapid rise of the construction industry is accompanied by the shortage of resources and labor, and the construction technology level can not fully meet the requirements of economic development. Construction units and construction units are increasingly demanding to improve construction technology to alleviate the problems of resources and labor. In this context, it is particularly important to improve the mechanization level of building construction and improve the management system of building construction.
In recent years, with the introduction of preferential policies related to prefabricated buildings, the government's support for prefabricated buildings has increased, and new prefabricated technologies and high-quality application cases have emerged in the construction industry. It can be said that prefabricated buildings are in an important stage of transformation and development, and may be an important field in the future construction industry market. Prefabricated buildings can be optimized according to the requirements of architectural design units, including area, structure, materials, decoration and other links. In order to promote the development of prefabricated buildings, studying and analyzing the seismic stress system of prefabricated building structures can provide owners with safe and reliable prefabricated building products. Compared with the traditional building structure, the prefabricated building embodies the importance of design, production, construction and management, and the whole process requires standardization, scale, construction and intensification. Under the industrialized building system, the construction unit should constantly strengthen the coordination of design standards, solve practical problems such as the backward level of traditional production technology through the improvement of mechanization level, and promote the long-term, sustained and rapid development of the construction market through the improvement of technical level and the large-scale development of prefabricated buildings.
1 Advantages of prefabricated buildings
1. 1 saving building resources consumes a lot of building materials and power fuel in the process of building construction. According to incomplete statistics, the energy consumption of China's construction industry is about 3 to 5 times that of other developed countries, and most buildings are still extensive production methods, which cannot meet the basic requirements of building energy conservation. Basic consumables such as cement and ore in the process of building construction belong to non-renewable resources, and it is difficult to form a recycling system for construction waste removed after building service. However, the assembled building adopts the way of centralized production and processing in the factory, and through reasonable structural safety design, the loss of building materials such as steel mold, wood, concrete and thermal insulation materials can be reduced. At the same time, compared with the field operation, the intensive construction operation in the factory can reduce the consumption of water and electricity. After the single building is demolished, the assembled building can be reassembled and spliced, which can realize the recycling of resources and greatly reduce the pollution to the environment.
1.2 Shorten the construction period
Precast external wall panels and other components used in prefabricated buildings will be reserved with slots for installing other components. After the structure is capped, the building can be protected and enclosed, which greatly reduces the consumption of working hours compared with the traditional protective support. Secondly, the assembly building adopts the factory intensive production mode, and the components of the single building have fixed production and processing workshops. The working procedures of each workshop are orderly, and the prefabricated components can be quickly poured, protected, insulated and painted, which greatly shortens the construction time of component prefabrication while improving the construction quality. In the component assembly stage of prefabricated buildings, the building can be raised within 1 ~ 2 weeks by using large cranes for on-site assembly, thus reducing the impact of on-site construction on the surrounding environment.
1.3 Reducing the project cost Because the components of prefabricated buildings are intensively produced in the factory, on the basis of improving the proficiency of employees, strengthening management arrangements can greatly increase the labor cost in the prefabrication stage. With the improvement of mechanization level, the production efficiency of related prefabricated components will be greatly improved. In addition, the standardized prefabrication construction of prefabricated buildings will strictly control the amount of materials, avoid material loss and reduce related costs to some extent. In the assembly and construction stage of prefabricated buildings, the number of installation workers needed is not too much, and the construction period is short. Generally speaking, the engineering cost of prefabricated buildings is much lower than that of traditional buildings.
1.4 Guarantee of engineering quality As the prefabricated buildings are intensively produced, the quantity and quality of concrete, steel bars and sandstone related components are strictly controlled, and the components are distributed in different workshops, thus ensuring the standardized production procedures of the prefabricated buildings. In the design stage of prefabricated buildings, the design unit will consider the structural safety, material control, section design and other factors of the building, and avoid possible quality problems in advance before prefabrication and assembly of prefabricated building components. In the assembly process of prefabricated buildings, the assembly process is carried out by skilled operators, which can ensure the improvement of the overall quality of prefabricated buildings.
1.5 Reduce the impact on the environment. The components of prefabricated buildings are carried out by skilled operators from production to assembly, especially in the on-site assembly process of prefabricated buildings, which does not require large-scale on-site concrete mixing and other processes, and the environmental noise is small; There is basically no floating dust and wastewater discharge at the site. Due to the short period of building assembly, it has little impact on the lives of surrounding residents.
2 prefabricated building construction technology
2. 1 construction difficulties and measures 1) During the pouring of prefabricated building precast slabs, the number and position of connecting steel bars should be consistent, and the accuracy of docking should be ensured when splicing different precast slabs. After taking certain measures to complete the reinforcement connection of precast slab beam, the relevant design and construction scheme should be made public. 2) When fixing the position of specific components, it is necessary to consider the layout of electromechanical pipelines to avoid secondary damage to electromechanical pipelines during the fixing process. Generally speaking, when fixing components, it is necessary to compare the layout of remote pipelines. 3) Due to the centralized production of prefabricated building components in the factory, accurate component dimensions are required. In the construction process, it is necessary to carry out fine construction according to the size of components to avoid incomplete closed combination of components in the construction process. It is not only necessary for operators to standardize the construction and production of components in strict accordance with the design requirements of drawings, but also to consider the practical problems that may occur in the process of on-site building combination in the design stage. 4) During the hoisting operation of prefabricated buildings, relevant components shall be protected by packaging, so as to avoid damage to prefabricated building components during hoisting and transportation. At the same time, the operator should also consider personal safety protection, and keep a certain distance from relevant components during the hoisting process. According to the safety requirements of construction, all operators on duty must have corresponding professional qualifications.
2.2 Key construction technologies and technological processes Precast prefabricated concrete has been put into use since the end of the 20th century, but due to the rough production industry, unreliable installation and poor safety and stability, the large-scale promotion of prefabricated buildings has been restricted. At present, all prefabricated buildings put into production have corresponding standards and specifications, but the research on the construction technology and technology of prefabricated buildings needs further study. In prefabricated buildings, the outer and inner panels of structures are generally prefabricated in factories, and can be fixed by various horizontal and vertical connection methods in the process of building assembly and lap joint. Folding can be considered for key parts such as interior wall slab and concealed beam, and concealed beam can be poured on site, but the processes such as binding and fixing steel bars for concealed beam can be handled in advance in the factory.
Precast reinforcement at the bottom of the floor and on-site pouring can alleviate the problems of poor integrity and low seismic grade caused by integral splicing of buildings. At the same time, considering the relevant construction technology in advance can reduce the consumption of materials such as concrete and steel plate. The construction process of prefabricated buildings generally includes: building area positioning, arranging wall columns according to design drawings, laying protective grids, hoisting external plates, installing prefabricated building components, binding steel bars of beams and columns, antique decoration of internal plates, burying related electromechanical pipelines, supporting shear wall templates, lifting stairs, and cast-in-place concrete in relevant parts.
3 prefabricated building quality management
1) The factory prefabrication and on-site assembly of prefabricated building components require higher technical level of operators, and the construction unit needs to train relevant technicians in professional knowledge and skills. Mastering the construction difficulties of prefabricated building structures can improve the comprehensive business ability of technicians, reduce rework problems caused by quality problems and promote the improvement of building quality. 2) When the prefabricated building components leave the factory, the construction unit must identify the technical indicators of the corresponding components, and the relevant components can only leave the factory after passing the quality acceptance. In the process of component transportation, it is necessary to formulate a reasonable transportation plan in combination with transportation distance, transportation volume and other factors. For the parts whose corners are easy to wear, protect the relevant parts. When the components are transported to the designated construction site, certain guarantee management is also needed in the process of stacking and storage of components.
3) For the on-site assembly of prefabricated buildings, the design unit and the construction unit should optimize the design by combining the architectural characteristics, construction links and many other factors. While reducing complicated assembly procedures, we should ensure the integrity and structural safety of the building structure, constantly establish and improve the quality management system and supervision system of prefabricated buildings, and promote the improvement of acceptance technology of prefabricated buildings. 4) For the large-scale popularization and application of prefabricated buildings, the construction unit needs to adopt information management technology, and conduct comprehensive management from the aspects of owner's demand procurement, customized design, standardized construction and on-site construction, which can promote the rapid improvement of prefabricated building technology.
4 conclusion
Prefabricated building is an important development trend of the future construction industry. The improvement of the construction technology level of prefabricated buildings is conducive to the innovation and development of the construction market. Quality control of prefabricated buildings is the key to building level. Advanced and reasonable design process and assembly system are the reliable guarantee for the long-term stable development of prefabricated buildings. The improvement of the comprehensive level of relevant building management technicians can comprehensively promote the popularization and application of prefabricated buildings.
The above are collected and sorted by Zhong Da Consulting Company.
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