3. Vibrating Tables

Try these first

1. 1.

   What is the maximum workability limit for using surface vibrators?

   Hint

   Think about how high the concrete can be before problems occur.

2. 2.

   What do surface vibrators primarily help to eliminate?

   Hint

   What happens when air is trapped in concrete?

3. 3.

   What is the role of surface vibrators in concrete?

   • To add air
   • To consolidate concrete
   • To dry concrete

   Hint

   Think about what happens when you shake a liquid.

4. 4.

   True or False: Surface vibrators can be used for concrete with workability levels exceeding 75 mm.

   • True
   • False

   Hint

   What is the maximum workability allowed?

5. 5.

   You are designing a concrete slab with a thickness of 120 mm. Discuss whether you would use a surface vibrator or needle vibrator, and justify your reason.

   Hint

   Consider the thickness limitation introduced earlier.

6. 6.

   A project requires consolidation of a very dry concrete mix. Discuss how you would set the vibration amplitude and frequency for effective consolidation.

   Hint

   Think about how the consistency of the mix relates to vibration needs.