Bedding Layer for Precast Slab Houses

In precast slab houses, laying a bedding layer is an important construction step with specific methods and functions.

Using Demolished Precast Slabs from Old Houses for Foundation Bedding Layers

If demolished precast slabs from old houses are used as bedding layers for foundations, there are two common methods. One is to use them directly as bedding layers, and the other is to use them as non-demolishable formwork for casting floor slabs on the ground floor. If used as the bedding layer at the bottom of strip foundations, they should be cut into short pieces according to the excavation width of the new foundation (taking two- or three-story houses as an example, with an excavation width of 80 - 100 cm), and the direction of the precast slab reinforcement should be perpendicular to the strip foundation. First, compact and level the foundation trench, then place the short precast slabs horizontally. Next, create a 10-cm concrete bedding layer, lay the foundation reinforcement on top, then pour the foundation, build the brick toe, and finally carry out the construction of the ground beam.

Thickness and Load-Bearing Capacity of the Leveling Bedding Layer for Precast Slabs

In the interior design of multi-story residential buildings from the 1990s, to ensure the load-bearing capacity of precast slabs and the indoor space height, a cement bedding layer is laid on the floor slabs as a leveling layer. The thickness of the bedding layer is usually between 20 mm and 50 mm, and the specific value needs to be determined according to the load-bearing capacity of the precast slabs and the interior decoration requirements. If the precast slabs have higher load-bearing requirements or the interior decoration requires higher flatness, the thickness of the bedding layer may increase accordingly. The cement bedding layer can not only be used for leveling but also enhance the overall load-bearing capacity of the floor slabs, effectively disperse the load pressure on the floor slabs, and extend the service life of the floor slabs.

Functions of Foundation Bedding Layers (Applicable to Precast Slab House Foundations)

• Leveling the foundation pit: Level the uneven foundation pit to provide convenient conditions for subsequent reinforcement binding and formwork erection, ensuring the accuracy and standardization of construction.
• Protecting the reinforcement: Isolate the reinforcement from the soil to prevent the reinforcement from rusting due to chemical reactions with substances in the soil, and also prevent rainwater from soaking the foundation, ensuring the stability of the foundation.
• Dispersing pressure: Disperse the pressure transmitted from the upper structure, reduce the risk of house settlement, and ensure the safety and stability of the house structure.