Reinforcement of Prefabricated Slabs in Rural Houses

The following methods can be used for reinforcing prefabricated slabs in rural houses, and the choice should be made based on the house structure, load requirements, and economic conditions:

1. Reinforcement with I-beams as crossbeams This method enhances the overall stiffness of the prefabricated slabs by adding a steel structure main frame. During specific operations, select the profile specifications (such as No. 20 steel) according to the load requirements. Evenly arrange three I-beam crossbeams along the span direction of the prefabricated slabs, crossing them with the slabs in a '+' shape. Add I-beam columns at both ends and fix them to the wall using chemical anchors or welding. This method has a short construction period and low cost, but it is necessary to ensure that the wall bearing capacity meets the reaction force requirements of the newly added steel structure, making it suitable for light-load scenarios.

2. Addition of a concrete composite layer Increase the load-bearing capacity by increasing the floor thickness. During construction, it is necessary to first remove local prefabricated slabs (such as in the mid-span area) to set up crossbeams, forming a '+' beam system, and then pour a 40-60 mm thick reinforced concrete composite layer to integrate the old and new structures. It is necessary to reinforce the walls simultaneously: For old brick walls, structural columns or ring beams need to be added to disperse the vertical loads transmitted from the floor and prevent local wall crushing. This method has a high safety factor, but it has a long construction period, high cost, and significantly increases the building's self-weight.

3. Adhesion of carbon fiber composite materials to the slab bottom Suitable for scenarios with a small increase in load (such as adding lightweight partition walls). High-strength carbon fiber cloth is adhered along the main reinforcement direction of the prefabricated slabs, transmitting stress through epoxy resin adhesive and increasing the flexural stiffness by 10%-30%. Construction points: Thoroughly remove the dust from the slab bottom, adhere it in 3-5 layers at a thickness of 0.1-0.2 mm, cure each layer for 12 hours, and make U-shaped anchoring at the ends to prevent peeling. This method has a small increase in self-weight, but its long-term durability requires regular inspection.

4. Addition of a steel beam system to the slab bottom Reduce the burden on the prefabricated slabs by changing the load transfer path. Add H-shaped steel or channel steel secondary beams to the slab bottom, with a spacing controlled at 1.2-1.5 meters, and connect both ends to the main structure through steel supports. Key control points: The steel beam specifications need to be determined through structural calculations (such as HN200×100 shaped steel). Reinforcing ribs need to be set at the supports to prevent local buckling, and shear connection treatment needs to be carried out at the contact surface with the prefabricated slabs. This method is suitable for large-span space renovations but requires a professional team for construction.

5. Enhancement treatment of slab joints For issues such as insufficient placement length of prefabricated slabs (<50 mm) or joint cracking, add L50×5 angle steel supports on both sides of the slab joints, drill holes at intervals of 300-500 mm, and connect them with M12 tie rods. Precautions: The tie rods need to apply a pre-tightening force of 50-60 N·m, the contact surface between the angle steel and the prefabricated slabs needs to be filled with structural adhesive to ensure joint work, and a 48-hour load test needs to be carried out after construction to verify the effect.