Where did Vanke's prefabricated housing industrialization go?

It's called assembling a house. When it comes to the "residential industrialization" of prefabricated houses, people often think that developed countries such as Japan, Europe and America use cranes to build houses like building blocks: all components that can be decomposed on the construction site are prepared in advance according to unified standards on the production line of the workshop, and then transported to the construction site to be assembled like building blocks. Buy a small villa, wait for 20 days, at most three months, and you can live in it, and you don't have to worry about the deformation of the house, the wall cracking and water leakage. This part of the prefabricated components, called "PC components", is the abbreviation of English precast concrete components, that is, the abbreviation of "precast residential concrete components", which is an important way to realize the industrialization of housing. When assembling a house, the site construction personnel first determine the position of PC components by setting out, and then lift the components with tower cranes. When hoisting, a special steel pole is used, which is connected with the component through steel wire rope and lifting ring, and is lifted at a uniform speed by the lifting arm and slowly rotated to the floor. After reaching the floor, the installer installs the components in place through the wind rope and adjusting bolts. The hoisting of a PC bay window takes about 5- 20 minutes, and it requires a conductor and three hoisting workers. Assembled houses reduce the links of steel bar binding, formwork support and concrete pouring in traditional construction sites, reduce potential safety hazards and reduce dusty situations. Previously, in the PC component laboratory, we saw the manufacturing process of these PC components: using a metal mold to open the mold on the "mold processing line", and then pouring concrete into the mold on the "PC processing line" to complete the casting. This technology is also used in landscape architecture. Outside the laboratory workshop, we saw precast blocks made of concrete, some imitating marble and some imitating wood grain. According to the engineer, domestic 3D printing partners have found them before and want to "customize" components for them, and the cost is relatively low. As a result, the finished product is very rough and completely unusable. Standardized aluminum alloy formwork: make your wall smoother. In the traditional building construction process, the formwork for the main structure construction is made of wood. With the development of technology, aluminum alloy formwork and steel formwork have been used by developers. The traditional wood pattern construction technology relies more on the skills of workers, and its accuracy and stability are poor. Through systematic die matching and on-site standardization, aluminum dies for prefabricated houses can achieve higher accuracy and ensure stable quality. The most important thing is that the traditional wooden model is easy to expand and leak slurry when pouring concrete, and the vertical leveling accuracy of the structure is poor. In the later stage, a thick plastering layer is needed for leveling, which is prone to the quality hidden danger of hollowing and cracking. The assembled aluminum alloy formwork for houses has high strength and precision, which can save the plastering and leveling process and reduce the situation of hollowing and cracking. Aluminum molds also have limitations. When the apartment structure of a building can't meet the same standard, the wooden formwork can be cut and processed on site, but the aluminum formwork can't. In this regard, the field engineer explained: "Our standardized units are all investigated and analyzed, considering the performance of building ventilation, lighting and heat preservation. And combined with the needs of customers, repeatedly demonstrate and modify, and provide customers with satisfactory products as much as possible. " Precast indoor partition: make construction easy and environmentally friendly. On the way to the house to see the "prefabricated indoor partition", the field engineer compared the construction site with "clean kitchen": "We also want to provide a safe and comfortable environment for the workers on the construction site in a safe, clean and tidy environment, which can also promote the construction quality." The prefabricated interior partition wall is prefabricated by the factory and assembled on site, that is, the plates are arranged according to the house type. After the factory is finished, they are transported to the site and put together one by one. What are the benefits? According to the field engineer, first of all, the vertical flatness accuracy of wallboard is high, and the error is about 3 mm The improvement of accuracy can save the process of plastering and leveling, thus reducing the quality hidden dangers such as hollowing and cracking of the wall. Moreover, the wallboard is light and high strength, which is convenient for construction. Only two workers are needed to operate during construction, so the work efficiency is high and the construction period can be shortened by about half. Secondly, the assembled interior partition wall also meets the requirements of national standards in terms of earthquake resistance, fire prevention and sound insulation; Thirdly, lightweight wallboard uses part of construction waste, which belongs to green materials. What standards does China refer to when assembling a house? China's construction industry began to adopt multi-storey assembled shear wall structure (commonly known as large plate structure) 0 years ago. However, due to the immature prefabrication and assembly technology at that time, the standard of building materials was low, the sound insulation effect was poor, the external wall leaked during use, and the criticism of poor seismic performance was exposed completely during the Tangshan earthquake. Since 1980s, prefabricated houses in Beijing have been gradually replaced by cast-in-place concrete. Japan has also had a painful lesson of earthquake casualties. After the Kobe earthquake in 995, modular housing construction began to be popularized. At that time, Hyogo Prefecture, the epicenter of the earthquake, implemented the "immortal bird" plan, requiring buildings to survive in moderate earthquakes, and the Japanese government also proposed the "zero death" plan. Later, various advanced seismic measures such as lightweight materials with excellent seismic performance were widely used. In 200 1 year, Japan suffered the highest earthquake in the history of human observation, accompanied by a devastating tsunami. Facts have proved that Japanese architecture has withstood the test of 9-degree earthquake. It is worth noting that xu teacher said that whether the building meets the seismic performance target is completed in the drawing design stage, and then an expert group with the qualification of construction drawing review will conduct the drawing review. After the drawings are reviewed, the design meets the standard, and then whether the construction is carried out according to the drawings or not, the construction process will be accepted by parts, such as concrete, wallboard, steel bar, decoration, water and electricity, fire protection, etc. After the acceptance of each part, all processes are completed through the general acceptance. Are these houses earthquake-resistant and waterproof? From the investigation of major earthquake disasters around the world, it can be found that more than 95% of casualties are caused by the damage or collapse of buildings, and the seismic performance of a house mainly depends on the load-bearing beams and columns. The prefabricated houses produced by our company adopt the system of "internal pouring and external hanging". Load-bearing shear walls and beams and columns are cast-in-place by traditional reinforced concrete, which can bear the internal forces caused by various loads and effectively control the horizontal forces of the structure. PC bay windows, prefabricated interior partitions, etc. are only non-structural components, which will not affect the bearing capacity of the building. Moreover, the prefabricated part and the cast-in-place part are connected with steel bars, and the whole is also very solid. The seismic requirements of prefabricated building structures are higher than those of traditional cast-in-place methods. At present, in the industry code, the seismic performance of the connection parts is required to be better than that of the traditional cast-in-place components. The waterproof problem of the gap between prefabricated parts is difficult to deal with. In this regard, Vanke engineers explained that the PC bay windows are connected by cast-in-place structure, the prefabricated parts have embedded steel bars, and the cast-in-place parts bite each other. The so-called "gap" has been covered by concrete liquid; The prefabricated interior wall is made of adhesive and treated by joint. As for the bathroom, it is also waterproof according to national standards, such as waterproof paint. How far has the prefabricated "housing industrialization" gone in China? At present, housing industrialization has reached a high penetration rate in developed countries, especially in Japan, where about 0% of housing is built in an industrialized way, and the prefabrication rate in Shandong reaches about%. In China's big cities, the prefabrication rate of houses can reach about 40-0%. Shanghai Pujiang Ruihe New Town's 50,000-square-meter affordable housing is the first residential project with high prefabrication rate in China, with a prefabrication rate of 50- 0%, which was completed last year. Beijing's first "housing industrialization" project-Majiqiao public rental housing in Tongzhou District will be delivered this year 10. About 0% of the whole project, such as laminated slabs, stairs, balcony slabs, and some internal and external walls, are industrialized prefabricated. According to statistics, the dust and muck in construction sites have decreased by 3% and 4% respectively. The cost and policy problems forced the process of housing industrialization in China to fade out with the demographic dividend, and the road for cheap migrant workers to build houses gradually narrowed. Since 1999 was formally put forward, it has entered the second decade. However, due to the low participation of housing enterprises, immature industrial chain, high cost, lack of strong policy support and constant market doubts, the process of housing industrialization in China is still slow. First of all, every item of housing industrialization will increase the cost. The price is determined by the market, and the increased cost can only be borne by the developers themselves. "If PC bay window, aluminum alloy touch panel and prefabricated interior partition are used together, the cost per square meter will increase by about 300-400 yuan, in which the cost increase of aluminum mold and prefabricated interior partition is relatively low, and the incremental cost of PC bay window is about 0 times of these two items." It is understood that due to cost reasons, most industrialization projects are also selectively adopted and have not been fully popularized and applied. At present, the process of housing industrialization in China is roughly equivalent to that in 1980s. The biggest obstacle is high cost and immature industrial chain. Especially for PC components, due to the small production scale, there is not only a small choice, but also the production value-added tax of components calculated by paint is more, and the products can only maintain a higher price. It is understood that although there are many factories producing PC components in the Pearl River Delta, they mainly supply Hong Kong and Japan. On the one hand, the degree of housing industrialization in these two areas is high and the demand is large. On the other hand, cities are more developed and offer more generously. Although for the sake of technological innovation, environmental protection and more practical shortening of the construction period, some developers expressed their willingness to do such a thing. For example, this month Vanke signed the Strategic Cooperation Framework Agreement with Beijing Housing Corporation and Beijing Residential Architecture Design and Research Institute to jointly develop residential industrialization, but more mainland developers are still waiting to see. Secondly, the national standards and policies related to assembling houses are not standardized. People in the industry have called for more than once to build a sound policy and institutional system. As the only unit in China that formulates technical standards for housing industrialization, experts from China Architectural Standards Design and Research Institute said that technical standards related to housing industrialization are already in the process of compilation, and some mature, perfect and appropriate standards will be combined. However, the policy subsidies and incentive mechanisms are still immature. At present, some awards have been given to the assembled houses in Beijing and Shanghai. For example, in 20 1 1 year, Beijing issued a policy to attract real estate enterprises to participate in the plot ratio and housing area incentives. Enterprises that actively promote the application of products and technologies certified by authoritative departments will be given preferential treatment and inclination in finance and financing. Shanghai issued a document in 2003, which turned individual housing into a hard target. In 2004, the proportion of "prefabricated house area" was increased to 30%, and special funds were given according to the prefabricated rate, and eligible PC commercial houses were also given rewards not exceeding 3% of the planned construction area. New residential land projects and government affordable housing in Shenzhen were built in the way of residential industrialization from 2000 to 2005, and 3% of the construction area was awarded for pre-selling the third floor in advance.