Prefabricated Column for Prefabricated Houses

The production and installation of prefabricated columns for prefabricated houses involve multiple key steps, requiring strict adherence to process specifications to ensure quality and safety.

Production Process

1. Mold Preparation and Concrete Pouring
   Before concrete pouring, rubber strips should be inserted into the gaps between the mold and the steel reinforcement to prevent slurry leakage. During pouring, a gantry crane with a hopper is used to evenly inject concrete into the mold. While pouring, a vibrating rod is employed to compact the concrete thoroughly, and an iron trowel is used to smooth the surface, paying special attention to the flatness around embedded parts.

2. Curing and Demolding
   During the curing stage, the fixtures for the embedded parts should be removed first. Then, the mold table is covered with an oxygen-enrichment棚 (oxygen-enrichment shed, here it might be better to use a more standard term like 'curing shed' if applicable in context, but for direct translation we keep it as is for now) to accelerate the growth of concrete strength through steam curing. After steam curing is complete, the steam pipes are removed, and the strength of the component is checked to ensure it meets the standards. For demolding, an electric wrench is used to remove the mold bolts, and rubber hammers and crowbars are used to separate the mold from the component. The molds are then stacked and categorized.

3. Quality Inspection and Storage
   Before storage, tools such as a protective layer thickness gauge and a tape measure are used to inspect the protruding length of the steel reinforcement, the position of embedded parts, and the dimensions of the component to ensure compliance with acceptance specifications. The concrete surface should be free of severe depressions, and dimensional deviations of various parts should be controlled within allowable limits.

Installation Process

1. Construction Surface Cleaning and Elevation Control
   Before hoisting the column, residual debris and oil stains on the concrete and steel reinforcement surfaces should be cleaned to prevent the formation of an isolation layer after grouting. For the first-floor column, the elevation is adjusted using shims placed at three or four points under the column, with the elevation set at the design value + 20mm. For upper floors, bolts are used for control, and the height and verticality of the column are adjusted by tightening or loosening the bolts.

2. Hoisting and Positioning
   Special lifting fixtures and steel wires are used to connect to the pre-embedded lifting points at the top of the column. Collisions should be avoided during hoisting. When the bottom edge of the column rises to 30cm above the ground, hoisting is paused, and a chain block is used to level the column and check the firmness of the lifting. When it reaches 60cm from the working layer, hoisting is paused again. Construction personnel hold the column to control its direction, and it is slowly lowered into place when the bottom sleeve aligns with the pre-embedded steel reinforcement on the ground.

3. Adjustment and Fixing
   During installation, a 2m level is used to straighten the column. Temporary fixing is achieved using adjustable diagonal support rods, with at least two rods in each direction. The support points should be no less than two-thirds of the column height from the bottom of the column. The verticality, levelness, and elevation are corrected using the adjustable rods on the support rods. Only after meeting the specification requirements can the temporary supports be removed.

Technical Case Study

In the Shanghang Environmental Protection Science and Technology Industrial Park project, technologies such as beam-column joint clamping-type corbels and prefabricated double-column cup-mouth rapid installation were applied, replacing traditional support systems. This significantly reduced overall costs, with solid waste emissions during the construction phase reduced by over 90%, demonstrating remarkable energy-saving and emission-reduction effects.