What's the difference between an assembled builder and a civil builder?

China's existing construction technology path (called traditional technology) is formed in 1982, that is, reinforced concrete cast-in-place system, also known as wet operation. Objectively speaking, although it has contributed a lot to the rapid development of urban and rural construction, its disadvantages are also very prominent: first, it is extensive and the waste of steel and cement is serious; Second, the water consumption is too large; Third, the construction site is dirty, chaotic and poor, which is often an important pollution source of inhalable particulate matter in cities; Fourth, the quality common fault is serious, and the problem of crack and leakage is outstanding; Fifth, the labor cost has soared, making it difficult to recruit workers, manage workers and control the quality of workers. This shows that the traditional technology should be changed, and with the requirements of energy saving and emission reduction, it is necessary to speed up the transformation and vigorously develop factory-built prefabricated buildings.

The difference between prefabricated buildings and traditional buildings

Traditional technology is the mainstream construction mode of on-site pouring in China's construction industry at present, that is, the operation mode from erecting scaffolding, formwork support, binding steel bars to on-site pouring concrete. The difference between prefabricated concrete buildings and cast-in-place reinforced concrete buildings lies in the different design, production, transportation and construction methods. Because of the need of field splicing, the design method and construction method of components and joints have changed. Compared with the two technologies, the biggest feature is the change of production mode, which is mainly reflected in five aspects: standardization of architectural design, factory production of parts, assembly of on-site construction, integration of structural decoration and informatization of construction process. Its main advantages are improving the efficiency and quality of engineering construction, ensuring construction safety, improving economic benefits, low carbon and energy saving, saving resources and realizing sustainable development.

The main features of prefabricated buildings are as follows:

(1) Assembled construction requires less materials to be processed on site, thus reducing environmental pollution;

(2)PC components are produced by mechanized numerical control equipment in the factory, which improves the accuracy of PC components, thus ensuring the quality of assembled construction projects;

(3) Heavy machinery and equipment are put into the site to reduce the labor force, which can effectively reduce the project cost;

(4) In the production process of 4)PC prefabricated components, integrated production can be adopted, such as the combination of external wall insulation materials and reinforced concrete. New technology can reduce construction procedures, improve overall efficiency and ensure project quality.

Compared with the traditional wet operation, the prefabricated building construction:

(1) The number of on-site workers will be greatly reduced, and the professional requirements of workers will be improved. Assembled building construction does not need a series of processes such as formwork support and pouring, and the corresponding number of workers will be greatly reduced. Compared with buildings with the same volume, the number of modern prefabricated buildings is reduced by about 50% compared with traditional cast-in-place construction. Of course, the professional technical ability of the component hoisting workers required for the construction of prefabricated buildings is higher than that of traditional construction workers, and professional prefabricated construction workers need to undergo a series of theoretical and practical training before taking up their posts.

(2) The efficiency, quality and safety of engineering construction have been effectively improved. A large number of components are produced in the factory, which reduces the long construction period under the traditional mode and effectively improves the efficiency of engineering construction. For example, the Changsha "Xiaotian City" built by Yuanda Science and Technology Company, a subsidiary of Hunan Yuanda Science and Technology Group, has a height of more than 200 meters and a construction area of 1.8 million square meters. It took only 57 days to build the main floor of 1.9, which attracted wide attention from professionals and media at home and abroad. Similarly, because the components are prefabricated in the factory, the quality of wall columns, beams and slabs can be more effectively controlled, and there is no longer a scene in which workers work around cast-in-place components or tie rolled steel bars on ultra-high columns, so the construction safety is more guaranteed.

(3) Reduce resource consumption and make the construction site more tidy and orderly. According to the data released by the National Development and Reform Commission on 20 12, the per capita freshwater resources in China are about 2 100 cubic meters, which is only 28% of the world average. At present, about two thirds of cities in China are short of water, and about one quarter of cities are seriously short of water. The shortage of water resources has become one of the important factors restricting the sustainable development of economy and society. After changing from the traditional cast-in-place construction mode (wet operation) to the prefabricated construction mode (dry operation), the consumption of water resources is obviously reduced, which is of great significance to the sustainable development of China's construction industry. In addition, the use of traditional wooden formwork in construction site is greatly reduced, while the steel formwork used more in component prefabrication plant can be recycled for a long time. At the same time, the orderly stacking of components on the construction site and the reasonable distribution of lifting points will also make the construction site more tidy and orderly, which will help to change everyone's impression of the messy construction site.

(4) changes in jobs and types of work. With the change of technical and management requirements for relevant personnel in the design, manufacture and construction stages of prefabricated buildings, new technical and management positions have emerged in prefabricated buildings.

Table of new posts and related resource requirements arising from prefabricated building construction

The transformation of prefabricated buildings can be summarized as the following five major changes: the mode of production has changed from "manual" to "mechanical"; The site is changed from "construction site" to "factory"; The practice has changed from "construction" to "final assembly"; Factory production personnel changed from "skilled workers" to "operating workers"; Migrant workers have changed from "migrant workers" to "industrial workers". Minimize the constraints of human factors (people at the operational level). Because of this change, during the construction of prefabricated buildings, the contents of some traditional jobs have also changed.