Prefabricated Concrete Floor Slabs for Houses

Prefabricated concrete floor slabs for houses were commonly used modules or panels in early 20th-century construction. They have gradually been replaced by cast-in-place structures but still have specific applications.

Manufacturing Process and Types

Prefabricated concrete floor slabs are produced through factory-based manufacturing: First, a hollow mold is made using wooden planks. Reinforcing steel bars are placed inside the mold, and concrete is poured. After drying, the wooden planks are removed to form the finished product. Depending on structural differences, they can be classified into two types: solid slabs and hollow slabs. Hollow slabs achieve lightweighting by reducing non-load-bearing concrete, lowering material consumption while maintaining load-bearing capacity, making them suitable for construction scenarios sensitive to self-weight.

Application Scenarios and Reasons for Obsolescence

Early prefabricated slabs were widely used in floor slabs for low-rise buildings, highway ditch covers, and roof insulation layers. Their advantages include high construction efficiency (direct hoisting after factory prefabrication) and lower costs (standardized production reduces on-site processes). However, as construction technology has advanced, their drawbacks have become apparent:

• Poor integrity: Prefabricated slabs are connected via crossed steel bars, but joint strength is lower than that of cast-in-place concrete, making them prone to cracking under external forces like earthquakes;
• Limited functionality: Hollow structures have weaker sound insulation and thermal insulation performance, making it difficult to meet modern building requirements for comfort;
• Low design flexibility: Fixed dimensions make it difficult to adapt to complex architectural forms. Modern buildings generally adopt frame structures or reinforced concrete cast-in-place structures, enhancing structural stability through integral pouring and allowing flexible piping arrangements, significantly improving safety and functionality.

Installation Specifications and Precautions

Installing prefabricated slabs requires strict adherence to procedures:

1. Hole sealing: Use concrete blocks to seal holes in the floor slabs to prevent grout leakage during pouring;
2. Steel bar treatment: Bend the floor slab steel bars upward, hoist them onto the formwork, then bend them downward at a 45-degree angle to cross with adjacent slab steel bars. Add continuous steel bars to enhance connections;
3. Elevation control: Ensure the top surface of the floor slab is level with the beam to avoid excessive thickness of the finishing layer affecting ceiling height.

Price Reference

Prices for prefabricated slabs vary significantly based on specifications, applications, and regional differences:

• 12 cm load-bearing reinforced concrete hollow slabs: 12-31.35 yuan per piece;
• Prestressed hollow roofing slabs (12 cm): 18 yuan per piece;
• Interlayer slabs for rural self-built houses: 15.8 yuan per piece. Prices typically include basic materials and simple processing fees. If custom dimensions or special properties (e.g., fire resistance, corrosion resistance) are required, costs will increase further.

Although prefabricated slabs are no longer the mainstream choice, they still have a market in cost-sensitive scenarios like temporary buildings and agricultural facilities. Their standardized production model also provides a reference for rapid construction.