Concrete and its reinforcement

Also see:
5.2

3.1.10Installation of reinforcement

Reinforcement shall be installed in accordance with the design. Issues to take into account include:

  1. shape, placing and condition of reinforcement bars
  2. lapping bars and mesh
  3. support for reinforcement

Shape, placing and condition of reinforcement bars

Main reinforcing
bars
Should be parallel to the span, or as detailed in the design.
Slab reinforcementShould be located near the bottom of the slab, with the main reinforcing bars placed first and the secondary bars on top.
BeamsShould have the main reinforcing bars placed inside the links.

Reinforcement should be:

  • bent using appropriate equipment and placed in accordance with the design
  • clean and free from loose rust and contaminants, especially shutter-releasing agents and oil.

Lapping bars and mesh

Reinforcing bars or mesh should be lapped according to type and size as indicated by the designer to ensure that loads are fully transferred across the lap. Any additional laps require the designer’s approval.

Support for reinforcement

Spacers should be either concrete blocks (no more than 50 x 50mm) or ready-made of steel or plastic. Supports should be placed no more than one metre apart, or closer where necessary.

Spacers for parallel bars should be staggered to avoid creating a plane of weakness in the concrete. Supports for top steel should be chairs, or other proprietary products.