The value of Vee-Bee time for low workability as per Indian standards is prescribed as
Correct Answer: B. 5-10 seconds
📚 Detailed Explanation: Vee-Bee Time for Low Workability
Why B (5–10 seconds) is correct: The Vee-Bee consistometer test (IS 1199) measures the time (in seconds) for concrete to completely remould under standard vibration. Classifications:
• >20 s: Very low workability
• 10–20 s: Very stiff / Very low
• 5–10 s: Low workability (answer for this question)
• 3–5 s: Medium workability
• 0–3 s: High workability
Option A (2–5 s) = medium. Option C (20 s single point) = very low boundary. Option D (20–30 s) = extremely stiff.
• >20 s: Very low workability
• 10–20 s: Very stiff / Very low
• 5–10 s: Low workability (answer for this question)
• 3–5 s: Medium workability
• 0–3 s: High workability
Option A (2–5 s) = medium. Option C (20 s single point) = very low boundary. Option D (20–30 s) = extremely stiff.
Vee-Bee Time Classification
| Vee-Bee Time (s) | Workability |
|---|---|
| >20 | Very low |
| 10–20 | Very stiff / low |
| 5–10 | Low |
| 3–5 | Medium |
| 0–3 | High |
- Low workability Vee-Bee time = 5–10 seconds per IS 1199.
- Vee-Bee is preferred for stiff, dry mixes unsuitable for slump measurement.