Standard Prefabricated Panels for Building Construction

Standard prefabricated panels for building construction were commonly used as floor slabs in early 20th-century architecture. These are concrete prefabricated components manufactured and processed at a prefabrication yard and directly transported to the construction site for installation. The following provides a detailed introduction from multiple aspects:

Structural Dimensions: For residential use, the maximum span of prefabricated panels is 4.2 meters, without a fixed modulus; customization is required for spans exceeding this limit. In the southwest region, special load-bearing panels must be used. The width is predominantly 500mm and 600mm, with a splicing error not exceeding 5 millimeters. Narrow panels of 40 centimeters are sometimes used for secondary structures. Common thicknesses are 120mm and 150mm, with 12 centimeters being sufficient for ordinary floor slabs. The length generally follows a 300mm modulus, such as 3000, 3300, etc., with special lengths like 3800 and 4000 also available. The maximum length for ordinary panels is 4200.

Live Load Capacity Ratings: Generally, residential buildings use Grade 1 and Grade 2 panels. Grade 1 panels can withstand a live load of 1kN/m², while Grade 2 panels can withstand 2kN/m². In the southwest region, the minimum requirement is Grade 4 panels, which can withstand a live load of 4kN/m².

Classification: There are two types: solid and hollow. The hollow structure achieves lightweighting by reducing the non-load-bearing concrete portion. Hollow prefabricated panels are made by leaving the non-load-bearing areas empty to reduce weight and save costs. However, the use of prefabricated hollow panels is no longer advocated today, and cast-in-place structures are more commonly used in building construction.

Characteristics:

• Advantages: They can shorten the construction period, reduce costs, and offer fast and low-cost construction, making them suitable for rural house building.
• Disadvantages: Existing prefabricated panel houses generally have issues with weak earthquake resistance, poor sound and heat insulation, and a service life of approximately 30-50 years. Their earthquake resistance is inferior to that of cast-in-place slabs, and caution should be exercised when using them in high-rise buildings.

Application Scenarios: Originating in the early 20th century, they were mainly used for floor slabs and roof insulation layers. Residential buildings constructed in China before 1985 often adopted this type of structure. Additionally, they have a wide range of applications in construction, such as cement panels covering ditches beside highways and cement panels used as insulation layers on rooftops.