In recent years, prefabricated concrete structures have rapidly advanced in China.
Building standardization rates abroad are already very high, especially in the United States, where the standardization rate has reached 100%. In 2017, Sichuan Province planned to complete 5 million square meters of prefabricated buildings across five pilot cities, including Chengdu and Leshan, achieving an assembly rate of 30%. This included 3 million square meters of new construction in Chengdu alone.
The Sichuan Provincial Department of Housing and Urban Rural Development emphasized that government-funded projects should actively adopt prefabricated buildings. A certain percentage of prefabricated buildings must be incorporated into the annual construction land supply, with this proportion increasing year by year. Additionally, for construction land using prefabricated buildings, land transfer fees can be paid in installments.
Projects with a prefabrication rate above 30% may use an invitation-to-bid method after approval, where specific legal entities or organizations are invited to bid. Other prefabricated building projects generally adopt the engineering general contracting bidding model.
Today, we will explore the key points of prefabricated assembly construction technology for your reference.
1. Key Points for Installing Prefabricated Stacked Balcony Panels
(1) Prefabricated balconies are lifted using four lifting rings embedded in the panels.
(2) When hoisting the balcony panel, pause approximately 500mm above the working surface to adjust position before proceeding slowly with installation.
(3) After aligning the control line and placing the panel, make fine adjustments to ensure it is level, then use a U-shaped bracket to adjust elevation.
(4) Once installed, calibrate the balcony carefully to ensure quality.
2. Installation and Construction of Prefabricated Composite Panels
(5) Use modular lifting beams when hoisting composite panels to ensure slow, stable lifting.
(6) Pause about 300mm above the working layer during lifting to adjust panel direction. Avoid collisions and lower steadily to maintain panel integrity.
(7) Install temporary supports beneath the panels with 150cm spacing between points, setting 2-3 rows of supports per bay.
(8) For structural layer construction, double-layer supports should be used. Supports can only be removed after the cast-in-place concrete reaches at least 70% of the design strength.
3. Key Points for Hoisting Prefabricated Wall Panels
(9) To save time replacing lifting points on steel wire ropes during hoisting, the lifting beam has two lifting points on one side. The other side has lifting points numbered according to component needs.
(10) Use modular lifting beams and connect steel wire ropes to the panel’s reserved lifting rings with shackles. Lift the exterior wall panel to 500mm above ground, then check component quality and lifting ring connections before continuing.
(11) Nail a 500mm-wide, full-length multilayer board to the outer corner of the wall panel before lifting. Lift slowly and evenly to avoid damaging the panel edges.
(12) When hoisting wall panels, the tower crane should raise them about 600mm above the working layer. Construction personnel then hook the panels with sliding ropes and gently lower them into place.
4. Key Points for Installing Prefabricated Bay Windows
(13) Bay windows are lifted using lifting ears, bolts, and reserved nuts embedded in the structure.
(14) After connection, slowly move the bay window to about 300mm from the work surface following position lines. Adjust bolts to align with through-wall holes, then use a customized U-shaped horizontal interlocking measure set and sliding ropes to guide the bolts into the wall panel connection holes.
5. Key Points for Prefabricated Beam and Slab Construction
(15) Prepare prefabricated pedestals as required, paying attention to anti-arch settings.
(16) Pour concrete normally, ensuring thorough vibration compaction and applying isolation agents to formwork.
(17) Perform prestressing and tensioning after wet curing, once concrete reaches 80% strength.
(18) Tension symmetrically, verifying with stress-controlled elongation values.
(19) Follow the tensioning procedure: start at 0 → initial stress → over-tension by 5% hold for 2 minutes → anchoring.
(20) Grout promptly, usually with cement slurry or mortar, maintaining a grouting pressure of 0.5–0.7 MPa.
6. Installation and Construction of Prefabricated Staircase Boards
(21) When installing prefabricated stair treads, pause about 500mm above the work surface to adjust their orientation. Move slowly to avoid damage from vibrations. Once roughly in place, use a pry bar for fine adjustments based on control lines, then weld and secure.
Thank you for reading. If you have any thoughts or questions, please feel free to leave a message. The Engineering Cost Big Data Network looks forward to collaborating with you to advance the domestic construction industry’s application level.
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