Multi-story Prefabricated Panel Buildings

Multi-story prefabricated panel buildings are a form of construction centered around prefabricated concrete components, primarily divided into two categories: prefabricated panel houses and prefabricated panel buildings, each with specific structural characteristics and historical application backgrounds.

Structure and Characteristics of Prefabricated Panel Houses

Prefabricated panel houses are constructed using prefabricated panels as the main components, built from factory-made cement elements (including solid or hollow structures). Hollow prefabricated panels achieve lightweighting by reducing non-load-bearing concrete, but due to insufficient structural integrity, existing prefabricated panel houses commonly face issues such as weak earthquake resistance and poor sound and thermal insulation, with a service life of approximately 30-50 years. This construction method originated in the early 20th century, and residential buildings constructed in China before 1985 often adopted this structure, which has now gradually been replaced by cast-in-place structures.

Structure and Limitations of Prefabricated Panel Buildings

Prefabricated panel buildings use prefabricated concrete floor slabs as the main floor components, commonly seen in urban residential buildings from the 1970s to 1990s, primarily featuring brick-concrete structures. Their core characteristics include:

1. Component Prefabrication and Assembly: Floor slabs and some walls are prefabricated in factories and then transported to the site for assembly, with walls mostly being brick or prefabricated concrete wall panels.
2. Limited Spatial Layout: Restricted by the dimensions of prefabricated panels (maximum span of 4.2 meters, width of 500/600mm, thickness of 120/150mm), the floor plan design is fixed, with small room spans (3-4 meters), poor north-south ventilation, and low ceiling heights (2.6-2.8 meters).
3. Structural Dependence on Load-Bearing Walls: Walls are mostly load-bearing, with floor slabs connected to the walls via prefabricated panels, making the overall structure dependent on the load-bearing capacity of the walls and offering limited flexibility for renovation.
4. Variations in Load-Bearing Grades: Residential prefabricated panels are classified into Grade I (1kN/m²) and Grade II (2kN/m²), with the southwestern region stipulating a minimum of Grade IV (4kN/m²), requiring selection based on the usage scenario.

General Characteristics and Current Status of Prefabricated Panels

In addition to being used for flooring, prefabricated panels can also serve as trench covers and roof insulation layers. Their advantages include shortened construction periods and reduced costs, but hollow prefabricated panels, due to insufficient integrity, have gradually been replaced by cast-in-place structures. Modern construction tends to favor cast-in-place techniques to enhance structural earthquake resistance and spatial flexibility.