Specifications of Old-Style Prefabricated Panels for Houses

The specifications of old-style prefabricated panels for houses (mostly prestressed hollow slabs used in the 1980s and 1990s) mainly include thickness, width, length, and hole structure, as detailed below:

1. Thickness
Old-style prefabricated panels typically come in two thicknesses: 120mm and 180mm. The 120mm-thick panels are mostly used in rooms with smaller spans, such as kitchens and bathrooms, to bear lighter loads; while the 180mm-thick panels are used in larger-span areas like living rooms and bedrooms, which need to withstand greater live loads and self-weight. Some special scenarios may use thicker or thinner specifications, but the above two are the most common.

2. Width
The standard widths are primarily 500mm, 600mm, 900mm, and 1200mm, with 600mm and 900mm being the most widely used. For example, a 600mm-wide panel often has a four-hole structure, while a 900mm-wide panel usually has a six-hole structure. Additionally, in some regions, there are colloquial terms like 50-centimeter (500mm) five-hole panels and 60-centimeter (600mm) four-hole panels, which actually refer to the same or similar specifications.

3. Length
The length is customized according to the room's width and depth, ranging from 2.1 meters to 6.6 meters, with a common modulus of 300mm (e.g., 3.3 meters, 3.6 meters, 4.2 meters, etc.). In residential buildings, 4.2 meters is the longest standard specification used, and lengths exceeding this require custom production. The length selection should consider the structural load-bearing requirements of the building to avoid insufficient load-bearing capacity due to excessive spans.

4. Hole Structure
Old-style prefabricated panels are hollow, with holes that are circular or elliptical in shape. The hole diameter is usually 60-80mm, and the number of holes is adjusted according to the panel width. For example, a 500mm-wide panel may have five holes, a 600mm-wide panel may have four holes, and a 900mm-wide panel may have six holes. The main purposes of the hole design are to reduce self-weight, save concrete materials, and improve sound insulation through the air layer. Some special specifications, such as panels with dimensions of 360×50×6 (in millimeters) or 400×80×6, may correspond to non-standard hole numbers or sizes and need to be confirmed based on specific production standards.

Summary: The selection of specifications for old-style prefabricated panels should comprehensively consider room functions, span requirements, and material properties. Their standardized design not only met the demand for rapid construction at the time but also reflected a balance between structure and economy.