Illustrated Guide to Reinforcing Prefabricated Slab Houses

Reinforcing prefabricated slab houses can be achieved through various methods, and the appropriate solution should be selected based on the house's structure, extent of damage, and reinforcement needs. Below are common reinforcement methods and their operational key points:

Reinforcement for Openings in Prefabricated Floor Slabs

If openings need to be made in prefabricated floor slabs, targeted reinforcement measures should be taken based on the location of the openings. When openings are made in the mid-span: Carbon fiber sheets of equal strength should be pasted on both sides and the ends of the opening to compensate for the loss of flexural bearing capacity caused by the opening. Before operation, a detector should be used to locate the position of the steel bars to avoid accidentally cutting them during the process, which could affect structural safety. When openings are made at the edge of supports: Polymer mortar should be filled in to enhance the local shear bearing capacity and prevent cracks caused by stress concentration at the support due to the opening.

Reinforcement of Old-style Rural Prefabricated Slab Houses

Old-style rural prefabricated slab houses often require reinforcement due to structural aging or increased loads. Reinforcement with I-beam Crossbeams: The spacing of the crossbeams should be determined based on the specifications of the profile. For example, three 20# steel beams can be spaced out and intersect with the prefabricated slabs in a '+' shape. The ends should be supported and fixed to the walls with I-beam columns to form an overall load-bearing frame. Reinforcement by Adding Concrete Layers: If the floor slab's bearing capacity is severely insufficient, some prefabricated slabs can be removed to add crossbeams. Vertical beams can be added on the crossbeams to form a '+' beam system, and then a concrete layer of no less than 40mm thick can be poured. At the same time, the walls should be reinforced with columns to disperse the pressure from the floor slab on the walls and prevent cracking due to excessive local stress.

Reinforcement of Prefabricated Hollow Slabs

The reinforcement method for prefabricated hollow slabs should be selected based on the extent of the increased load. When the load increase is minor: Carbon fiber sheets can be directly pasted on the bottom of the slab to enhance the tensile capacity of the slab bottom using the high strength of the carbon fiber. During operation, ensure that the carbon fiber sheets are firmly bonded to the slab bottom without any voids. When the load increase is significant: Steel beams can be added to the bottom of the slab to transfer the load to the walls or columns, changing the original load-bearing mode of the hollow slab and reducing the risk of stress concentration in the slab body.

Common Reinforcement Methods for Prefabricated Slabs

Section Enlargement Reinforcement Method: A reinforced concrete structural layer of no less than 40mm thick is added to the top or bottom of the slab to increase the bearing capacity by increasing the cross-sectional dimensions. This method is suitable for cases where the concrete on the slab body is aging or the reinforcement is insufficient. Reinforcement with Pasted Carbon Fiber Sheets: This method is suitable for scenarios where the tensile capacity at the slab bottom is insufficient. Carbon fiber sheets are pasted to the slab bottom with epoxy resin to form a composite load-bearing layer and enhance the flexural performance. Reinforcement by Changing the Structural Load Transfer Path: By adding supports, crossbeams, or steel frames, the load is transferred to more stable structural parts. This method is suitable for cases where the local load is excessive or the structural layout is unreasonable.