1. Concrete shall be mixed as near as possible to the place of deposit and no additional water shall be added to the concrete after it has left the mixer. The concrete shall be to site by manually.
2. Concrete shall be placed and compacted while fresh and before it has taken its initial set. This shall be performed at the latest within 45 minutes after mixing, which is defined as the time at which the cement is added to the aggregates.
3. The arrangements for placing concrete shall be such that the material may be conveniently handled and placed in the required position without contamination, re-handling or segregation and at the required workability.
4. Concrete shall be compacted during placing by immersion vibrators. The stick vibrators shall be operated vertically. The fastening of vibrators to the reinforcement or other built in items shall not be permitted. Concrete shall not be re-vibrated to remove or reduce cracks.
5. Concrete shall not be allowed to fall freely from a height which may cause damage and distortion of the reinforcement, other embedded items or formwork, preferably 1.0m and below. In no case shall concrete be allowed to fall freely from a height greater than 1.50m.
