Procedure

As per IS 1199, the procedure for conducting the Vee-Bee test is as follows:

1. Preparation of Apparatus: Place the Vee-Bee consistometer on a rigid, horizontal base free from external vibrations. Ensure the container is firmly fixed to the vibrating table using wing nuts.

2. Positioning of Mould: Dampen the inside of the slump mould and place it inside the container. Swing the funnel over the mould, lower it into position, and tighten the screw to prevent movement.

3. Filling the Mould: Fill the mould with fresh concrete in three equal layers (each about one-third height), ensuring uniform and symmetrical distribution.

4. Compaction: Tamp each layer with 25 strokes of the tamping rod:

5. Bottom layer: strokes slightly inclined and spirally towards the center

6. Upper layers: strokes penetrate slightly into the previous layer

7. Leveling the Surface: After the top layer is tamped, remove excess concrete and level the surface using a sawing and rolling motion of the tamping rod.

8. Removing the Funnel and Mould: Loosen the screw, swing the funnel away, and carefully lift the mould vertically within 7 ± 2 seconds without disturbing the concrete. Note if the concrete collapses or touches the container walls.

9. Placing the Transparent Disc: Swing the transparent disc over the concrete and lower it gently until it just touches the highest point. Record the slump value, if applicable.

10. Start of Vibration: Loosen the screw to allow free movement of the disc. Start the vibrating table and stopwatch simultaneously.

11. Observation of Remoulding: Observe the concrete through the disc as it remoulds from a conical to a cylindrical shape under vibration.

12. Recording Vee-Bee Time: Stop the stopwatch when the underside of the disc fully contacts the cement paste. Record the time (in seconds) as the Vee-Bee time.

13. Time Constraint: Complete the entire test within 5 minutes from the start of filling the mould.