For Quality Concrete, Oztec Suggests:
1. Select the largest vibrator
suitable for the job.
2. Insert the vibrator vertically,
allowing it to sink to the desired depth by its own weight.
Forcing it may lock it between
3. Hold the vibrator 5 to 15
seconds then slowly lift vibrator up, staying behind the trapped
air's upward movement. Allow
seconds for each 2 foot distance to avoid re-trapping air.
4. A slight up and down movement
will close the hole formed by the vibrator.
5. Withdraw the vibrator quickly
when near the top to prevent churning air into the top layer.
6. Move vibrator and re-insert at
a distance 1 ½ times the Radius of Action…As shown in the diagrams.
7. Allow vibrator to pass 3 to 6
inches into the preceding layer to ensure knitting the two layers
together, insuring a good
preventing "lift lines" when forms are removed.
8. Try to limit pours to 2 to 3
feet high, so air has less resistance to escape.
9. Do Not use vibrator to move
concrete laterally…it causes segregation (use a shovel). Place
vibrator in the center of
mounds to knock