blue header

Welcome to the Precast Flooring Federation

All members of the PFF manufacture in factory controlled conditions to the highest standards using the latest methods and machinery. A typical factory layout is shown below:

Manufacture methods

Products are generally made using either an extruding machine or a slipforming machine.

Slipforming

This method involves concrete being fed through the machine while it is being winched along the casting bed over the prestressed wires. The profiles are produced by the moving formers as the machine progresses.

Concrete is enormously strong in compression, but weak in tension. Steel wires and strands are the tendons of prestressed concrete floors.
High tensile strength tendons and high compression strength concrete, combine in a clever balancing act to deliver a higher performance than ordinary reinforced concrete. First the tendons are stretched. Then high strength concrete is cast around them.
The concrete is carefully cured to achieve the designed strength. When the concrete has achieved the required strength the tension is released. The cured concrete grips the steel tendons, preventing them from returning to their original length. So, the concrete is permanently held in compression by the steel tendons.

By locating the steel tendons below the centre of the beam, greater compression is imparted to the lower half, where it is required for its load bearing capacity. This gives a degree of upward camber to the beam which is a function of the prestressing force and the position of the tendons. All the energy used in stretching the tendons is now stored in the precast flooring unit. Strength and lightness skillfully combined.

 

Versatility

Precast concrete floors are versatile. Holes for services can be preformed at the factory, and non standard units can be cut to suit even the most complex of schemes.


Cutting Notches

Cutting Slabs
Click on the pictures to see approx 1Mb videos of slabs being cut to size (above right) and notches being cut (above left).

 

bluefooter