Reinforced masonry design is based on the reinforcing steel carrying all of the internal tensile forces. This design requires that the grout be properly consolidated so that there is adequate bond with the reinforcing steel, and that the masonry and the reinforcing steel act together.
Consensus masonry specifications require that the grout be consolidated by mechanical vibration, and then reconsolidated by mechanical vibration after initial water loss and settlement has occurred. Typically, the mechanical vibration is performed by a pencil vibrator. This approach can be both cumbersome and time-consuming, particularly when using high-lift grouting.
An alternative method which eliminates the problems associated with a pencil vibrator is to use the reinforcing bar itself as the vibrator. A vibratory device is simply placed over the top of the reinforcing bar and the grout is consolidated by the bar’s vibration. This approach reduces the time required for vibration and eliminates the mess.