Have a prestressed concrete pavement relaxed

Anyone who wants to have a prestressed concrete ceiling installed today usually chooses prefabricated elements which are relatively easy and quick to assemble with a corresponding heavy equipment. For the planning and production of the required elements, the corresponding building plan copies must be available at an early stage to the manufacturer and supplier of the prestressed concrete floor.

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In principle, a prestressed concrete ceiling is laid on masonry or wall concrete and fixed by means of reinforcement anchors. The constructional minimum contact surfaces must be just as guaranteed as the flat surfaces. The prestressed concrete floor or the individual elements are prepared ready for installation ex works. These include the cutting to the centimeter and the relaxation of the reinforcing steel in the concrete.

As prestressed concrete ceilings are among the largest components in building construction, the delivery always requires a "four-tonne". Semi-trailer with 18 meters in length and 24 meters turning circle, the arrival and departure must be made possible to and from the construction site. The client or client bears the responsibility for this.

Unloading and interim storage

At the construction site, placing a crane must be planned and prepared. At the construction site, a crane footprint must be kept clear, which allows moving the prestressed concrete floor from the semi-trailer to the installation site and, if necessary, to an intermediate storage location. The support legs of the crane need sufficiently fixed ground, which is optionally separately prepared for example by compaction.

In the case of a necessary interim storage, as in the case of multi-storey building construction, the client must provide for a secured storage location on the construction site. Two parallel and transverse to the elements of the prestressed concrete ceiling designed wooden planks form the basis of the stack construction. Batch wood for further layers is brought by the supplier.

Hang up and place

Before laying the prestressed concrete slab, the positional positions on the bearing surfaces, the tops of masonry or concrete wall elements, must be marked. The construction and production-side tolerance for placement is defined as two millimeters. According to the blueprint, the first elements must be placed at the so-called compulsory points such as open staircases and fireplaces.

The elements of the prestressed concrete slab must be laid butt-jointed on the underside of the ceiling without creating any joints. Under no circumstances may the edges of individual elements over each other or wedged come to rest. Cuts to correct the position are prohibited on a prestressed concrete floor. The fit with the crane should be made and if necessary completely repeated.

Grouting concrete and aftertreatment

After aligning and, if necessary, correcting differences in the height of the elements and the supports, the anchorage of the ring anchors must be carried out with the bearing reinforcements. With grouting concrete, the lateral support of the prestressed concrete floor is completed and the decisive disc effect of the entire ceiling construction is fixed.

A professional after-treatment of the prestressed concrete slab according to the manufacturer's instructions is mandatory for the long-term durability. As construction progresses, heavy loads must be placed only near the supports.

Tips & Tricks

Follow in every detail the specifications of the manufacturer of the prestressed concrete floor to get the physical benefits of the "relaxed" ceiling. Renowned manufacturers keep a technical leaflet ready.

Video Board: Types of Concrete Joints in Prestressed Concrete Structures | Prestressed Concrete Structures