Compacting
- Use vibrators for effective compaction - needle vibrators for footings, beams and columns and surface vibrators for slabs and flat surfaces.
- Immerse the needle vertically to full depth and maintain it throughout the operation.
- Vibrate the concrete for about 15 seconds and withdraw the needle slowly.
- Ensure that the immersion points are spaced at a distance of 15 centimetres (for 20 millimetres diameter needle)
- Do not touch the centering plates of formwork or reinforcement with the needle of the vibrator.