Compaction factor for heavily reinforced section with vibration is ………….
Correct Answer: D. > 0.92
📚 Detailed Explanation: Compaction Factor for Heavily Reinforced Sections
Why D (>0.92) is correct: Heavily reinforced sections have closely spaced rebars that restrict concrete flow. Even with vibration, the fresh concrete must be fluid enough to reach all parts of the formwork before vibration consolidates it. A CF > 0.92 (high workability) ensures this. Lower CF values give stiffer mixes that would leave voids around dense reinforcement even with vibration.
Compaction Factor vs. Application
| Compaction Factor | Workability | Typical Application |
|---|---|---|
| <0.75 | Very low | Dry lean concrete |
| 0.75–0.85 | Low | Roads, pavements (vibrated) |
| 0.85–0.92 | Medium | Normal RCC (slabs, beams) |
| >0.92 | High | Heavily reinforced sections |
- CF > 0.92 = high workability required for congested reinforcement zones.
- Vibration does NOT replace workability requirements — it complements them.