Analysis of Prefabricated Panel House Construction

Prefabricated panel houses are constructed using prefabricated panels as the main components. The following provides an analysis from the aspects of construction foundation, historical and current status, characteristics, and problem cases:

Construction Foundation

Prefabricated panels are cement components manufactured in factories. During production, a wooden mold is first nailed together, then steel bars are arranged and cement is poured to form the panel. There are two types: solid and hollow. The hollow structure achieves lightweighting and cost reduction by reducing the non-load-bearing concrete.

Historical and Current Status

Originating in the early 20th century, prefabricated panels were initially mainly used for floor slabs and roof insulation layers. In China, most residential buildings constructed before 1985 adopted this structure. With the development of building technology, cast-in-place concrete and prefabricated buildings have gradually replaced traditional prefabricated panel houses. Since 2022, China has implemented a policy of renovating old residential areas, focusing on repairing and renovating prefabricated panel houses and only demolishing those that meet the criteria for dangerous buildings. Existing prefabricated panel houses have many problems, such as weak earthquake resistance, poor sound and heat insulation, and a service life of about 30 - 50 years. Some regions have already started demolition work.

Construction Characteristics

• Dimensions and Specifications: For residential use, the maximum span is 4.2 meters, and customization is required for longer spans. The width is mostly 500mm and 600mm. Common thicknesses are 120mm and 150mm. The live load capacity is classified according to different situations. Generally, Grade 1 and Grade 2 panels are used for residential buildings, and in the southwest region, the minimum is specified as Grade 4. The length is generally based on a 300mm modulus, but there are also special sizes, and the width has different hole counts corresponding to different sizes.
• Structural Classification: There are two types: solid and hollow. Hollow prefabricated panels can reduce weight and save costs because the hollow positions do not bear loads, but end plugs need to be added at the panel ends, and there are corresponding regulations for the seams of YKB panels.
• Advantages: They can shorten the construction period and reduce costs.

Problem Cases

There is a two-and-a-half-story self-built house where the floor slab on the first floor uses prefabricated 5-hole panels. Although the construction is simple, fast, and cost-saving, the assembled floor slabs have visible gaps and significant light leakage. Moreover, the house does not have inter-story ring beams, so during an earthquake, the prefabricated panels placed on the walls may collapse and cause injuries. There is also a one-and-a-half-story house where the first floor uses 5-hole prefabricated panels placed on a pitched roof. To prevent sliding, a horizontal 5-hole prefabricated panel is installed at the end.