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Reduce cold joints, honeycombing, and bugholes by training workers how to place and vibrate concrete in walls. The basic principles of placement and vibration are the same for any placing equipment used. If problems occur, however, corrective action can minimize their recurrence.

Using admixtures minimizes segregation. Their cost is offset by savings in labor through more efficient placement. Other ways of reducing segregation include increasing the sand or cement content, adding an air-entraining agent, or using a mineral additive, such as fly ash.

Arrange placing equipment so concrete has an unrestricted vertical drop into the forms. Don't separate the concrete by dumping it onto rebar or other embedded items. Direct discharge of concrete without chutes or trunks is possible with sufficient space and freedom from obstructions.

Most contractors use internal vibrators to consolidate concrete. If used properly, they do the best job of consolidation. They also help the concrete flow under blockouts, around waterstops, and between rebar. Consolidation levels or flattens the concrete surface then removes entrapped air bubbles. Vibrate the concrete until the larger air bubbles escape. Undervibration is more common than overvibration.