What is a Prefabricated Floor Slab House
A prefabricated floor slab house is a building constructed primarily using prefabricated panels, with its core components being factory-made cement elements that enable rapid construction through modular assembly.
1. Structure and Types of Prefabricated Panels
Prefabricated panels are cement components produced in factories through standardized processes. To make them, wooden molds are first nailed together, followed by the placement of a steel reinforcement framework and the pouring of cement, ultimately resulting in two types: solid and hollow. The hollow structure achieves lightweighting by reducing non-load-bearing concrete, lowering material usage while maintaining load-bearing capacity, making it suitable for large-span floor slabs or walls. Solid prefabricated panels, due to their dense structure, are often used in areas requiring higher strength.
2. Construction Methods and Characteristics
The construction of prefabricated floor slab houses adopts a “modular assembly” approach, where entire walls, floor slabs, and other components are prefabricated in factories and then transported to construction sites by cranes for direct assembly. This method is akin to “building with blocks”, offering significantly higher construction efficiency than traditional cast-in-place techniques, greatly shortening project timelines and reducing on-site wet work, thereby minimizing the impact on the surrounding environment. During the 1970s and 1980s, prefabricated panel houses became widely popular in China due to their low cost and rapid construction, particularly dominating multi-story residential construction.
3. Existing Issues and Governance Directions
Limited by early technology, prefabricated panel houses have two core defects: poor seismic performance, as rigid connections between components are prone to fracture or displacement during earthquakes; and insufficient durability, with long-term use leading to concrete carbonation and steel reinforcement corrosion, resulting in floor slab cracking or wall leakage. To address these issues, the country is advancing systematic governance:
- Tiered assessment: Houses are classified into four categories—A (safe), B (basically safe), C (partially dilapidated), and D (wholly dilapidated)—based on the “House Safety Assessment Standards”.
- Differentiated renovation: A/B-rated houses are included in old residential area renovations, focusing on upgrading roofs, pipelines, elevators, and other facilities; C-rated dilapidated houses have their safety enhanced through wall reinforcement, floor slab strengthening, and the addition of seismic components; D-rated dilapidated houses may be included in expropriation and demolition plans to completely eliminate safety hazards.
Currently, with advancements in building industrialization technology, new prefabricated components (such as prefabricated concrete structures) have significantly improved seismic and durability performance through high-strength connection nodes and the application of composite materials, gradually replacing traditional prefabricated panel houses.
