Reinforcement of Ceilings in Prefabricated Slab Houses

The following methods can be used for reinforcing the ceilings of prefabricated slab houses, and an appropriate plan should be selected based on the house structure, load requirements, and construction conditions:

I. Reinforcement of Prefabricated Slab Ceilings

If the ceiling is a prefabricated slab ceiling structure, a dual reinforcement method using wooden strips and screws can be employed. During specific operations, wooden beams (such as 40mm×60mm wooden strips) should be fixed first to ensure a flat and firm contact surface with the prefabricated slabs. Subsequently, expansion screws should be driven into the wooden beams, with a recommended screw spacing of 30-50cm, forming a grid-like reinforcement system. This method is suitable for scenarios with minimal load increase and no obvious cracks in the ceiling, effectively enhancing the overall stability of the ceiling and preventing the risk of detachment due to vibration or slight deformation.

II. Bottom Plate Reinforcement Techniques

1. Carbon Fiber Adhesion Method: When the house load increases slightly (such as adding lightweight equipment), carbon fiber cloth can be directly adhered to the bottom of the prefabricated slabs. The carbon fiber should be fully laid along the span direction of the slabs, with an overlap length of no less than 20cm, and fixed with special adhesive. This method can enhance the tensile strength of the bottom plate, with a short construction period and minimal damage to the original structure.
2. Adding Steel Beams Method: If the load increases significantly (such as renovating into storage space), steel beams (such as H-beams or I-beams) can be added to the bottom of the slabs. The steel beams should be fixed to the walls using chemical anchors or expansion bolts, with spacing determined by calculations (usually 1.5-2m). The steel beams can change the load-bearing mode of the hollow slabs, converting dispersed loads into concentrated loads, significantly enhancing the load-bearing capacity.

III. Reinforcement of Old Rural Prefabricated Slab Houses

1. "I"-Beam Crossbeam Reinforcement: Use "I"-beams as crossbeams, determining the layout density based on the steel specifications (such as 20# I-beams, e.g., 3 beams per room, crossing the prefabricated slabs in an "X" shape). The ends of the crossbeams should be supported by "I"-beam columns, with the column bottom connected to the wall via embedded steel plates and the top welded to the crossbeams. This method is suitable for houses with large spans and strong wall load-bearing capacity, forming a frame-like support system.
2. Adding Concrete Layer: Pour a new layer of concrete (recommended thickness of 5-8cm) on the prefabricated slabs. Before construction, one prefabricated slab should be removed to serve as a crossbeam, and vertical beams should be added to the crossbeam (forming an "X"-beam structure). The new concrete layer should be connected to the original prefabricated slabs using rebar planting or shear keys to ensure integrity. This method can increase the floor thickness but requires simultaneous reinforcement of the walls (such as adding structural columns) to prevent wall cracking due to increased loads.

IV. Reinforcement for Hole Drilling and Pipe Penetration

If holes need to be drilled in the prefabricated slab floor for pipe penetration, and the hole location is in the mid-span of the floor (a weak load-bearing area), equal-strength carbon fiber cloth should be adhered to both sides of the hole. The width of the carbon fiber cloth should cover at least 20cm of the hole edge, and the length should extend 1-1.5m along the span direction of the slabs to compensate for the loss of flexural load-bearing capacity. Before construction, dust around the hole should be cleaned to ensure the penetration effect of the adhesive.