Benefits of fresh concrete to be vibrated
Fresh concrete that should be vibrated provides huge benefits. Freshly placed, unconsolidated concrete normally contains full of entrapped air bubbles. Concrete can attain a greater compressive strength and density with least air content mechanically i. e. with the help of high frequency (fast, repetitive) vibrations.
Thus, the concrete fulfill the present needs with regards to strength and density. The vibrator produces high frequency vibrations which are delivered to the components of the fresh concrete.
• Frictional forces among individual particles are significantly minimized.
• A flow process is formed.
• Air bubbles, excess water and paste are congested via capillary action and surface tensions are discharged and evaded to the surface.
Benefits of concrete vibration
• Superior density and consistency
• Superior compressive strength
• Superior durability (e. g. de-icing salt)
• Perfect bond with rebar, specifically in thickly reinforced sections
• Greater bond among the individually “wet” on “wet” placed layers
• Better quality exposed (fair-faced) surfaces
• Utilization of drier mixtures results in necessitating less cement.
Recognize your effective compaction diameter: For practical uses and as rule of thumb, approximate value should be taken for the operating diameter i.e. 10 times the vibrator head housing diameter.
Proper spacing should be retained while compacting large surfaces.
Proper spacing should be maintained while vibrating fresh concrete in walls.
Internal vibrators with dia (Ø) 30 (1.2”), 38 (1 ½”) and 45 mm (1.8”) should not be utilized because of poor or non-existing overlapping of the effective compaction Ø. It will result in producing a defective or inexpensive vibration method.
For superior effective compaction Ø and for more suitable, inexpensive compaction (less insertions, less time) preferably the following should be utilized :-
• Vibrators with diameters 57 or 65 mm, on the condition that the rebar allows it.
• The concrete will be compacted flawlessly due to the overlapping.
It is found that consistently and horizontally extended layers offer the superior outcomes in concrete compaction with approximately 50 cm (20”) thickness.