Innovative work measures in Hefei, Anhui Province to promote the high-quality development of prefabricated buildings

August 25, 2021 is the National Low-Carbon Day, with the theme "Low-Carbon Life, Green Building for the Future".

As a large carbon emitter, the construction industry is closely related to people's lives. Accelerating the development of green buildings represented by prefabricated buildings and advancing the industrialization of buildings are an effective way for the construction industry to achieve the "dual carbon" goal.

During the "13th Five-Year Plan" period, Hefei City started construction of 17.57 million square meters of prefabricated buildings, with an average annual growth rate of nearly 50%. In the first half of this year, the city started construction of 3,777,800 square meters of prefabricated buildings, and the area of newly increased prefabricated buildings increased by more than 70% year-on-year. In August, the "Fourteenth Five-Year Plan for Prefabricated Building Development Plan (2021-2025)" of Hefei was officially approved. At the same time, Hefei is committed to implementing the prefabricated building in-plant supervision mode, and has issued the "Prefabricated Building In-plant Supervision Implementation Guide (Trial)", which is the country's first special guiding document in this field!

Facing the pain points of quality supervision and implementing the same source of construction supervision

Prefabricated buildings are strongly advocated by the state for their advantages such as conforming to the "four sections and one environmental protection", improving labor production efficiency and quality and safety levels, and promoting the resolution of excess production capacity. In the second phase of the Binhu International Convention and Exhibition Center, the application of such large-scale buildings has also continuously made breakthroughs, but some problems have also been encountered in the development process.

At present, the largest-span prefabricated steel structure exhibition building in China-Hefei Binhu International Convention and Exhibition Center Phase II

During the production of prefabricated components, affected by factors such as concrete ratio, raw material quality, hidden project quality control, construction technology, process control, etc., the finished product sometimes has quality defects such as poor flatness, deviation of component geometric dimensions, and inaccurate position of embedded parts. In the traditional production-delivery process, the construction party often finds these quality problems when the prefabricated components enter the site or during the quality inspection before installation. The contradiction caused by the rework of the project is prominent, which affects and restricts the release of the production capacity of the component enterprises, and raises the construction cost of the construction enterprise.

In order to improve the quality of prefabricated concrete components of prefabricated buildings and ensure the quality and safety of prefabricated buildings, the Hefei Urban and Rural Construction Bureau issued the "Guidelines for the Implementation of Hefei Prefabricated Building Supervision (Trial)" (hereinafter referred to as the "Guide") and emphasized that in the future, the construction unit should be responsible for organizing and coordinating the construction supervision work in the factory, that is, let the builders become the supervisors. This is a nationwide initiative that will effectively improve the pain points of the quality supervision of precast concrete components.

Clarify the responsibilities of manufacturing supervision personnel, and refine the implementation plan for manufacturing supervision

The construction unit participates in the production supervision work in the factory, clarifies the responsibilities of the production supervision personnel, and refines the implementation plan for the production supervision.

The "Guide" requires that the factory supervision personnel should have a professional technical title of construction engineering or above, 2 years or more of engineering practical experience, and the number should not be less than 2 in principle, and the person in charge of the factory supervision should be specified. The prefabricated component procurement contract should specify the content of the factory supervision work to clarify the responsibilities of the production and construction parties.

The "Guide" emphasizes that the factory supervisors need to review the prefabricated component design documents and change procedures, review the production plan, quality control plan, review the inspection conditions and capabilities of the manufacturer, and review the relevant inspection reports. It is not only necessary to check and accept the quality of the finished prefabricated components, review the quality certification documents of the factory, but also participate in the quality inspection of the production process and the first piece acceptance. During the entire manufacturing supervision process, the resident manufacturing supervision log shall be recorded, and the resident manufacturing supervision data shall be retained.

The "Guide" proposes that the resident manufacturing supervision agency should prepare a project resident manufacturing supervision implementation plan, and submit it to the construction unit for approval, clarifying the staffing, implementation scope, implementation procedures, measures and methods. The construction unit shall organize and carry out the resident supervision work including the general contracting unit (construction unit), design unit and production enterprise before the production of prefabricated components, and make relevant records.

At the same time, the "Guide" sets out specific requirements for implementation content and work depth from five aspects: raw materials and accessories acceptance, mold acceptance, concealed acceptance, finished product acceptance, and first article acceptance.

Strengthen component quality supervision and lead the construction of "green" transformation

The introduction of the "Hefei City Prefabricated Building Supervision Implementation Guidelines (Trial)" has effectively promoted the improvement of the construction industry's green supply chain, and explored a successful path for accelerating the green and low-carbon development in the field of prefabricated buildings.