Specification Requirements for Prefabricated House Beams

The specification requirements for prefabricated house beams cover multiple aspects such as deflection, dimensions, materials, dimensional tolerances, and quality, as detailed below:

Deflection of Pre-tensioned Prefabricated Beam Slab Beams: According to the "Code for Construction of Concrete Structures" GB50666, the deflection of beams on pre-tensioned beds must be strictly controlled, with a maximum allowable value not exceeding 2mm. This requirement ensures that the beams do not undergo excessive deformation under load, which could affect structural safety, and is a key indicator for ensuring the quality of prefabricated components.

Dimensional Requirements for Prefabricated Beams:

• Length: Typically ranges from 6 to 12 meters, with specific values determined based on the span of the building structure and design requirements to meet the load-bearing needs of different scenarios.
• Width: Generally ranges from 0.5 to 1 meter. Wider beams provide a larger load-bearing area, but material costs and installation difficulty must be considered to avoid over-design.
• Height: The standard range is 0.3 to 0.6 meters, requiring a balance between load-bearing capacity and space utilization to prevent reduced load-bearing capacity due to insufficient height or space wastage and safety hazards due to excessive height.

Material Requirements for Prefabricated Beams:

• Reinforcing Bars: Must use national standard HRB335 and HRB400 high-strength reinforcing bars, with cold bending tests required for bars with a diameter ≤ 25mm to ensure their plasticity and toughness meet requirements.
• Concrete: The strength grade should be C30 to C50 to meet the compressive and durability requirements of the beams.
• Embedded Parts: Must comply with relevant standards and specifications to ensure reliable connection with the main structure.

Dimensional Tolerance Requirements for Prefabricated Beams:

• Length Tolerance: An allowable deviation of ±10mm is permitted, as exceeding this range may affect the installation accuracy of components.
• Beam End Section Width Tolerance: Must not exceed ±5mm to ensure uniform structural loading.
• Height Tolerance: An allowable value of ±10mm is permitted to avoid reduced load-bearing capacity due to height deviations.
• Geometric Dimensions: Must strictly comply with design drawing requirements, with deviations not exceeding the design allowable range to ensure overall structural stability.

Quality Requirements for Prefabricated Beams:

• Surface Quality: Should be smooth and flat, without obvious scratches, unevenness, or cracking, with color and gloss meeting design requirements to enhance building aesthetics.
• Shape Dimensions and Deformation: Longitudinal and transverse deformations must be controlled within specified limits to prevent excessive deformation from affecting structural safety and functionality.