How to Make Prefabricated House Beams

The production of prefabricated house beams requires a rigorous process, covering design, processing, pouring, curing, and installation. The specific steps are as follows:

I. Construction Preparation and Foundation Construction

1. Site Planning: The site needs to be leveled and functional areas divided, including a steel bar processing yard, beam prefabrication area, and finished product storage area. The prefabricated pedestal should be designed according to the beam size. The foundation can adopt a concrete strip foundation or a reinforced concrete enlarged foundation. The pedestal surface should have high strength and reserve a clearance (such as 50cm) to facilitate the insertion of locking tie rods and ensure pedestal stability.
2. Material and Equipment Preparation: Materials such as steel bars, steel strands, and cement need to be inspected and qualified. Mixers, gantry cranes, tensioning equipment, etc., need to be overhauled and calibrated to ensure construction accuracy.

II. Steel Bar Processing and Binding

1. Steel Bar Processing: Cut and bend steel bars according to the design drawings to ensure the dimensions meet the requirements. For example, the web stirrups need to be precisely bent to the specified angle, and the positioning steel bars for the prestressed ducts need to be processed into a '#' shape.
2. Binding Sequence: Bind in layers on a dedicated pedestal in the following order: bottom plate bottom-layer steel bars → web stirrups → prestressed duct layout → top plate steel bars. The prestressed ducts should be fixed with positioning steel bars and sealed at both ends with sealing tape to prevent concrete infiltration.
3. Embedded Part Installation: Fix anchor plates, reserved holes, etc., in the steel bar framework. Strictly follow the drawings for positioning, with the error controlled within the allowable range.

III. Formwork Installation and Fixing

1. Formwork Treatment: Clean the formwork and apply a release agent before installation to ensure a smooth concrete surface.
2. Step-by-Step Installation:
   • Bottom Formwork: Adjust the position and elevation to ensure flatness.
   • Side Formwork: Lift it with a gantry crane and connect it firmly to the bottom formwork, with a verticality deviation of ≤2mm.
   • Internal Formwork: Assemble it in sections and then lift it as a whole. The bottom is supported on steel bar stools, the side plates are positioned with steel bars, and a pressure bar is set on the upper side to prevent floating.

IV. Concrete Pouring and Vibration

1. Mixing and Transportation: Mix the concrete strictly according to the mix ratio, with a slump controlled between 160-200mm. The transportation vehicle should travel at a constant speed to prevent segregation.
2. Pouring Sequence: Pour from one end in layers, first the bottom plate, then the web (longitudinally segmented and horizontally layered), and finally the top plate to avoid cold joints.
3. Vibration Method: Use high-frequency attached vibrators as the main method and immersion vibrators as the auxiliary method. Narrow areas such as the web should be compacted with a 30mm diameter vibrating rod to ensure no air bubbles.

V. Curing, Formwork Removal, and Installation

1. Curing: After pouring, cover with plastic film for moist curing for at least 7 days to prevent cracking.
2. Formwork Removal: Remove the formwork after the strength reaches 75% of the design value to avoid damaging the edges and corners.
3. Transportation and Installation: Transport with a dedicated beam transport vehicle and install on-site using a gantry crane or truck crane to ensure accurate positioning and firm connection.

By following the above steps, the production of prefabricated beams can be systematically completed, ensuring structural safety and durability.