Prefabricated Assembly House Construction
Prefabricated assembly house construction involves transferring a significant amount of traditional on-site work to factories, where components are manufactured and then transported to the site for assembly and installation. Taking the construction of prefabricated residential buildings in Shenzhen as an example, the process and key points are as follows:
Initiation of the Construction Process: After the completion of the cast-in-place main structures of the basement, podium, and the first two floors above ground, the standard floor assembly construction phase begins. During this stage, it is essential to monitor real-time information about the components throughout their design, production, transportation, and construction processes, enabling full-process information sharing and collaborative work. Mobile terminals are used in conjunction with BIM information platforms to guide on-site component installation, manage construction progress, and conduct three-dimensional simulations and visualizations of construction plans and site layouts.
Component Production and Transportation: Components are produced automatically according to component drawings and transported to the site as per the component arrival plan. During transportation, attention must be paid to protecting finished products and ordering components correctly. Prefabricated components can only be installed after passing on-site inspections.
On-Site Installation Operations: After surveying and setting out, special steel bar positioning inspection tools are used to verify the positioning and perpendicularity of reserved steel bars. Steel shims are placed, and the elevation is checked with a level. When the component is 1 meter above the floor level, it is manually guided down slowly. A mirror is used to observe whether the reserved steel bars align correctly. Once aligned, the component is slowly lowered into place. Subsequently, diagonal braces and 7-shaped brackets are installed. After correcting the wall positioning and perpendicularity, the hooks are removed, and other wall panels are installed in sequence. Dry hard cement mortar grout is used for sealing and compartmentalization. After sealing the gaps, grouting operations are carried out, including mixing the grout, testing its fluidity, sealing the lower injection holes, inserting the injection pipes for grouting, etc. When the grout emerges in a columnar shape from the upper opening, the upper injection holes are sealed one by one, and the injection pipe nozzles are withdrawn and the injection holes are sealed.
External Scaffolding and Interspersed Construction: Starting from the third floor, integrated self-lifting scaffolding is used. The scaffolding is attached to the prefabricated shear walls through embedded sleeves and connected to the scaffolding guide seats via scaffolding attachment components. While the exterior walls are being hoisted, interspersed work such as steel bar binding for the cast-in-place interior wall sections and installation and reinforcement of aluminum alloy formwork for the cast-in-place sections are carried out. When installing exterior wall panels, the supports for the composite beams and slabs are installed first. The composite beams and slabs are then hoisted to their designated positions in sequence, with interspersed steel bar binding and reservation and embedding of water and electricity pipelines.
Installation of Other Components: The standard floor construction process for prefabricated assembly buildings also includes the installation of prefabricated bay windows, prefabricated balconies, and other components. These installation processes also involve steel bar binding at the bottom of the floor slab, reservation and embedding of water and electricity pipelines, concrete pouring of the floor slab, and precision leveling of the cast-in-place floor surface.
