Concrete Prefabricated Panel House Walls

Concrete prefabricated panel house walls are a type of building wall structure made primarily of Portland cement and steel reinforcement frames, prefabricated into panel shapes using molds. They are now prohibited from being used in main structures but are still applied in some projects.

Structure and Types

Concrete prefabricated panel house walls are composed of Portland cement and steel reinforcement frames, formed into panel shapes through prefabrication processes. Based on their internal construction, these walls are divided into two types: solid and hollow:

• Hollow prefabricated panels are designed with internal voids to reduce weight and material costs. They are easy to construct and relatively inexpensive, having been widely used in brick-and-mortar buildings in the past to reduce on-site bricklaying time.
• Solid prefabricated panels have a denser structure but are heavier and more costly, with a relatively limited range of applications.

Specifications and Performance

The specifications of standard prefabricated panel walls are constrained by production processes and structural safety:

• The maximum span is 4.2 meters; lengths exceeding this require additional reinforcement or alternative structural forms.
• The width is typically 500mm or 600mm, and the thickness is mainly 120mm or 150mm, meeting requirements for load-bearing capacity and stability.

Defects and Reasons for Phase-Out

Despite their widespread use, inherent defects in prefabricated panel walls have led to their gradual phase-out:

• Poor thermal insulation: The high thermal conductivity of the materials makes it difficult to meet modern building energy efficiency standards.
• Insufficient structural stability: The connection methods between prefabricated panels and the main structure (such as welding or bolt fixing) are prone to loosening due to vibration or settlement.
• Weak load-bearing capacity: They cannot withstand significant loads, limiting their use in high-rise buildings or large-span spaces.
• Joint gap issues: Gaps between panels are prone to cracking due to material shrinkage or external forces, leading to water leakage and high maintenance costs.

Current Status and Alternative Solutions

Currently, concrete prefabricated panel walls are prohibited from being used in the main structures of new buildings. Cast-in-place concrete slabs have become the mainstream alternative due to their good integrity and adaptability. However, prefabricated concrete wall panels (such as prefabricated exterior and interior wall panels in prefabricated buildings) are still used as building components, but their design, production, and installation must comply with current regulations and pass special inspections for earthquake resistance and fire protection.

Management and Lifespan of Prefabricated Panel Houses

Existing prefabricated panel houses generally suffer from issues such as weak earthquake resistance and poor sound and thermal insulation. Their designed service life is 30-50 years, but this is not a mandatory retirement standard. Whether a house should be demolished depends on professional safety assessment results:

• Grade A, B: Structurally safe and can be used normally.
• Grade C: Requires partial reinforcement.
• Grade D: Identified as dangerous and must be demolished and rebuilt.