Roof Concrete Prefabricated Panels

Roof concrete prefabricated panels were commonly used floor slab components in early 20th-century architecture. They were processed and formed in factories and then transported to construction sites for installation, possessing specific structural characteristics and application scenarios. However, existing buildings have certain issues, and currently, repair and renovation are the primary approaches.

Structure and Manufacturing Process:
Concrete prefabricated panels come in two types: solid and hollow. The hollow structure achieves lightweighting by reducing the non-load-bearing concrete. During manufacturing, wooden planks are nailed together to form a hollow mold. Reinforcing bars are placed in the hollow section, and cement is poured in. After drying, the wooden planks are knocked off to form the prefabricated panel. In modern manufacturing processes, some prefabricated panels adopt pre-tensioning or post-tensioning techniques, combining steel strands with distribution bars to enhance structural strength. Some designs even incorporate foam materials to reduce weight and save on materials.

Application Scenarios:
Prefabricated panels are not only used for floor slabs but also widely employed in roof insulation layers, highway ditch cover plates, and other scenarios. Their standardized production model meets the needs of early industrialized construction, especially in multi-story residential and public buildings.

Existing Issues:
With the development of construction technology, cast-in-place concrete and prefabricated buildings have gradually replaced traditional prefabricated panel structures. Existing prefabricated panel houses generally suffer from weak earthquake resistance, poor sound and heat insulation, and have a service life of approximately 30-50 years. The structural connection joints are prone to a decrease in integrity due to material aging, making them susceptible to brittle failure under external forces such as earthquakes.

Policy Orientation:
Since 2022, China has implemented a policy of old building renovation, focusing on repair and renovation of prefabricated panel houses and only demolishing buildings that meet the criteria for dangerous structures. Renovation measures include adding insulation layers, reinforcing structural connection joints, replacing aging pipelines, etc., aiming to extend the service life of buildings and enhance living safety. For buildings with severe structural hazards, demolition and reconstruction are carried out through monetary compensation or property rights exchange.