The area of newly-started prefabricated buildings in Hubei Province in the first 9 months increased by 115.7% year-on-year

Prefabricated stair component-chip embedded point

The industrialization of building construction makes housing construction less polluting and more energy-efficient. On October 13th, it was learned from Hubei Province's new-type building industrialization and intelligent construction publicity training and on-site observation exchange activities that in the first nine months of this year, 16 cities and prefectures in Hubei Province except Shennongjia Forest Region have started a total of 628 new prefabricated construction projects, covering an area of 17.3 million square meters, a year-on-year increase of 115.7%.

Prefabricated buildings refer to buildings that are prefabricated and produced in the factory for building components and accessories, and assembled and installed on-site through reliable connections at the construction site. Since the beginning of this year, the prefabricated construction projects of different structural types in Hubei Province have been advancing steadily. From January to September, newly-started prefabricated concrete structure buildings were 9,313,900 square meters, a year-on-year increase of 85.5%, accounting for 53.8% of newly-started prefabricated buildings. Fabricated steel structure buildings amounted to 7,066.3 thousand square meters, a year-on-year increase of 154.9%; timber structure, light steel structure and other structural types were 919,900 square meters, a year-on-year increase of 302.2%.

According to reports, taking the prefabricated concrete construction project as an example, compared with traditional construction methods, it can reduce construction waste by 70%, water consumption by 25%, and save wood by 60% and cement mortar by 55% during the construction process.

It is reported that in 2017 and 2020, Wuhan, Yichang, and Jingmen were approved as national prefabricated building demonstration (example) cities. Tuanfeng Economic Development Zone in Huanggang City was approved as a national prefabricated building demonstration park, and 13 enterprises including China Construction Third Engineering Bureau and Hubei Guangsheng were approved as a national prefabricated building industrial base.

Prefabricated laminated panels-component identification

Industrialized housing construction is good and fast-the total construction period of labor has been reduced by more than 30%

Entering the prefabricated exhibition area, a prefabricated laminated board is marked with component identification on the upper left. "In the design phase, the assembled components are disassembled through BIM (Building Information Modeling) technology, and after the production is completed according to the established size, they are transported to the corresponding location for hoisting according to the component identification." The on-site staff introduced.

According to reports, the project uses three types of prefabricated components: prefabricated balconies, prefabricated stairs, and prefabricated laminated panels. Due to the small number of prefabricated components and the high degree of standardization, the production cost of components is effectively reduced. Compared with traditional construction methods, the total labor for prefabricated construction is reduced by more than 30%, and construction safety risks are greatly reduced. At the same time, the production of prefabricated components can be synchronized with the on-site construction. The pipeline pre-embedding and other processes are completed at one time in the factory. The construction is less affected by the weather, and the overall overall construction period is shortened by more than 30%.

The relevant person in charge of Hubei Guangsheng, Kuang Ling, said that for this project, the same 34-storey Building 3 and Building 7 are selected for carbon emission comparison. Building 3 adopts a prefabricated construction technique with an assembly rate of 50%, and Building 7 adopts a cast-in-place technique. According to statistics, No. 3 building reduced 4165 man-days during the construction phase; material saving was 5.5% in the main structure phase. The decoration stage saves 11% of materials, reduces 126 tons of construction waste, and reduces carbon dioxide emissions by 494.2 tons, accounting for about 10.37% of the construction stage. As the assembly rate increases, carbon emissions will be further reduced.

Is the construction time-saving and labor-saving, and is the cost higher?

"For projects with more than 100,000 square meters, the EPC (design, procurement, construction) project general contracting mode is adopted, integrated construction is implemented, and the design plan is optimized. Even if the assembly rate reaches 100%, the cost will not increase." Kuang Ling said that the company's 160,000-square-meter affordable housing project under construction has an assembly rate of 100%. According to estimates, the cost is slightly lower than that of traditional buildings.

Measured robot

The quality of industrial buildings is more assured

Next to the prefabricated stair components, technicians are holding a scanning gun at the "chip embedded point", and information such as the type of steel bar, concrete strength, operator, and use items is immediately displayed on the screen. "Every concrete precast component product used in the project has relevant information loaded into the embedded data chip, realizing the life-long traceability of the quality of the whole process."

"The entire production process of the pre-components is completed by automatic mechanical operations in the factory's assembly line, and the quality and dimensional errors of the finished components are far superior to traditional construction techniques." The on-site technicians said that the pre-component mechanized operation from production to hoisting is fully covered by quality supervision, which greatly reduces the impact of factors such as worker quality and technical ability on quality.

In the model room, a technician issued a scanning instruction through the "Measured Robot" mobile phone APP. One minute later, a flat view of the room scene appeared on the display of the triangle laser scanner in the house. "The measured robot is mainly used for civil construction delivery, hardcover, and house delivery acceptance. Through the laser 360-degree measurement of the whole wall value, the wall flatness, verticality, the squareness of the yin and yang angles, and the height and width of the door opening are automatically recorded in the intelligent management system. Avoid manual measurement and recording errors, data accuracy is higher, more accurate, and quality is more reliable. "The technician told the reporter that the project traditionally requires more than 3 full-time surveyors, and only 1 person is required to complete the corresponding work in combination with the actual survey robot.

Affected by the cross-construction of different work types such as masonry and window installation, as well as the quality of operators and quality inspectors, the leakage of external walls and external windows in traditional construction techniques has long plagued the owners. The relevant person in charge of the real estate of the project construction party said that the use of new technology combining fabricated components, ALC lightweight partition board, gypsum mortar and thin plastering, has reached the standard of free or thin plastering on the wall. It can greatly reduce the probability of hollow cracking of the wall surface, reduce the probability of leakage by 20 to 25%, and use a larger area.

The relevant person in charge of the Yichang Housing and Urban-rural Construction Bureau stated that the current implementation ratio of prefabricated buildings in new projects in Yichang City has reached 45%, and strives to achieve 100% of the prefabricated buildings in new projects in the urban area by the end of 2022.