Concrete

Concrete Slab on Ground and Footings

Concrete Superstructures

Patching and leveling horizontal concrete surfaces

Termite Interception Baiting Monitoring and Management

Concrete Fire Protection

General
This manual does not comprehensively cover the many potential problems that can arise in respect of the construction of reinforced concrete. It simply concentrates on some of the less obvious ones.

Formwork
Edge forms for suspended concrete slabs are often difficult to secure and keep straight. When permanent steel sheet formwork is used, preformed metal edge forms can also be screwed to the sheeting by short metal straps.

Reinforcement Cover
The lapping of welded fabric reinforcement in the top face of a slab will significantly increase the thickness of reinforcement and reduce the cover.

Vibration
Adequate vibration of all concrete using a mechanical vibrator is essential.

Curing
Contractors often neglect the correct curing of slabs. It may be expedient for the Builder to assume responsibility for applying and maintaining the curing system. Sprayed emulsions require less attention than moistening and covering the slab.

Recesses in Concrete Slabs
In order to achieve falls in tiled floors in bathrooms and the like, it is preferable to recess the concrete slabs otherwise there will be a lip at the tiled edge. This recess may be formed after the concrete has been screeded level. The corner position of recesses can be marked by fixing temporary vertical reinforcing bars to the fabric. Such bars should not puncture the membrane.

For large tiled areas, the slab should provide for uniform falls to wastes and associated pipework. If there is likely to be difficulty in achieving such uniform falls, it may be advisable to allow for a 40 to 50 mm screed laid subsequently by the tiler in accordance with AS 3958.1 Appendix A.. The thickness of the screed (if required), tile bedding and tiles should be shown on the structural concrete details, to ensure that the finished levels are appropriate.