Formwork

Summary

Formwork - Formwork is a structure used to mould concrete elements.

Technical Information

The formwork for a concrete floor slab consists of a ‘wall’ around the perimeter of the slab area, the height of which exactly matches the desired slab depth. The concrete is placed level with the top of the formwork so that a floor can be roller or truss screeded easily. It is important that the level of the formwork is constantly surveyed during construction operations and adjusted wherever necessary to maintain the correct level.

Formwork can be made of most structural materials; wood, steel, aluminium and plastic etc, but must be robust enough to resist the weight of the wet concrete as it is poured up to it. Wood is often used for smaller scale structures as it is inexpensive, readily available and easy to shape. In industrial concrete floors it becomes more economical to use more durable materials, like metals. Dowel formers can be permanently fixed to the face of the formwork, ready to receive a dowel sleeve to be installed into the face of the first pour.

The formwork is removed as soon as the concrete has set enough to support itself.

Armoured joints create a permanent formwork and provide anchorage to the slab with shear studs.