Prefabricated Hollow Slab for Building Structure

A prefabricated hollow slab is a prefabricated prestressed reinforced concrete floor slab with longitudinal channels inside and a hollow cross-section. It has advantages such as light self-weight, high load-bearing capacity, and material savings, and is widely used in modern buildings.

Core Features and Advantages

1. Light Self-weight and Material Savings:
   The prefabricated hollow slab reduces the amount of concrete used through its internal channel design, making it lighter in weight compared to solid slabs of the same span. This facilitates transportation and hoisting. For example, a 12-centimeter-thick floor slab costs approximately 18 - 31.35 yuan per meter. SP prestressed floor slabs, with technological upgrades, are more expensive (55 - 480 yuan per meter), but offer significant long-term cost-effectiveness.

2. High Load-bearing Capacity and Seismic Performance:
   It adopts a composite structure of prestressed steel bars (such as high-strength steel strands with a spacing of ≥1.5 centimeters) and ordinary cold-drawn low-carbon steel bars (with a cover thickness of 2 centimeters), combined with concrete of strength grade C30 or above. This enables large spans (up to 20 meters) and high load-bearing capacity, while also providing better seismic performance than traditional solid slabs.

3. Enhanced Architectural Freedom:
   It reduces the need for load-bearing structures such as columns and interior walls, providing greater flexibility in spatial layout. It is especially suitable for large-span and large-space buildings such as schools, shopping malls, and underground parking lots.

Application Scenarios and Technological Development

• Application Scope: It covers residential, commercial, educational, medical, and industrial buildings, and is particularly suitable for high-rise buildings and scenarios requiring flexible partitioning.
• Technological Iteration: In China, non-prestressed hollow slabs were used in the 1950s, and SP slab technology from the United States was introduced in the early 21st century. The national standard atlas for Prestressed Concrete Hollow Slabs (EHC Slabs), released in March 2025, adopts an extrusion molding process, achieving a span breakthrough of 20 meters and promoting industry standardization.

Specifications and Performance Optimization

• Size Specifications: The recommended thickness is ≥20 centimeters, with a height error of ≤5 millimeters and a fixed width of 90 centimeters. In designations such as Y - KB426 - 2, the last digit represents the load-bearing grade.
• Sound Insulation Improvement: The sound of walking on an ordinary floor slab is about 75 decibels, while the national standard requires ≤65 decibels. The prefabricated hollow slab can significantly reduce noise propagation by optimizing the channel layout and concrete compactness.

Through structural and material innovations, the prefabricated hollow slab balances lightweight design, strength, and cost-effectiveness, becoming an efficient and environmentally friendly standardized component in modern buildings.