Prefabricated Panel Roof Reinforcement

Reinforcing the roof of a prefabricated panel house can be achieved by pouring a reinforced concrete 'composite layer' on top of the prefabricated panels. The specific operations and principles are as follows:

I. Construction Steps

1. Surface Cleaning: Thoroughly remove floating dust, oil stains, and loose particles from the surface of the prefabricated panels to ensure a flat and solid base. If there are cracks or damages, repair and polish them in advance to meet the requirements, providing a good bonding foundation for subsequent construction.
2. Steel Bar Mesh Installation: Use steel bars with a diameter of 6 millimeters, woven into a square grid structure at 20-centimeter intervals. The steel bar mesh should maintain a gap of 3-5 millimeters from the surface of the prefabricated panels and be fixed with short steel bars or iron wires to prevent displacement during pouring. The role of the steel bar mesh is to connect the scattered prefabricated panels into a whole through its tensile action, enhancing crack resistance.
3. Concrete Pouring: Select fine aggregate concrete with a grade not lower than C25 (aggregate particle size ≤ 15 millimeters), with a thickness controlled between 5-8 centimeters. During pouring, it is necessary to vibrate and compact in layers to avoid defects such as honeycombs and pockmarks. Secondary troweling before the initial setting of the concrete can reduce surface shrinkage cracks.

II. Reinforcement Principle
Through the mechanical interlocking of the steel bar mesh and the chemical bonding of the concrete, the originally independent prefabricated panels are transformed into an integral load-bearing structure. The steel bar mesh bears tensile stress, while the concrete bears compressive stress. Their collaborative work can significantly enhance the roof's bending and shear resistance. At the same time, the composite layer increases the cross-sectional height of the roof, improving overall stiffness and effectively suppressing deformation.

III. Precautions

1. Before construction, check whether the prefabricated panels have severe aging or damage. If the load-bearing capacity is insufficient, reinforcement treatment should be carried out first.
2. The lap length of the steel bar mesh should be ≥ 200 millimeters, and the ends should be hooked and fixed to ensure continuous force transmission.
3. Concrete curing is crucial. Cover and maintain moisture within 12 hours after pouring, with a curing time of no less than 7 days to prevent cracking due to drying shrinkage.
4. This method is suitable for roof reinforcement with minor load increases or slight settlement. If there is structural damage, it should be combined with other reinforcement measures (such as adding supports, external prestressing, etc.) for comprehensive treatment.