A concrete having a slump of 6.5 cm is said to be ………..
Correct Answer: D. plastic
📚 Detailed Explanation: Consistency Classification by Slump
Why D (plastic) is correct: IS classification of concrete consistency by slump:
• 0–25 mm: Very low / Dry / Earth moist
• 25–50 mm: Low / Stiff plastic
• 50–100 mm (includes 65 mm): Medium / Plastic
• 100–150 mm: High / Flowing
65 mm (6.5 cm) falls within the plastic range (50–100 mm). Options A (dry) and B (earth moist) apply to 0–25 mm range. Option C (semi-plastic) = 25–50 mm range.
• 0–25 mm: Very low / Dry / Earth moist
• 25–50 mm: Low / Stiff plastic
• 50–100 mm (includes 65 mm): Medium / Plastic
• 100–150 mm: High / Flowing
65 mm (6.5 cm) falls within the plastic range (50–100 mm). Options A (dry) and B (earth moist) apply to 0–25 mm range. Option C (semi-plastic) = 25–50 mm range.
Consistency Classification
| Slump (mm) | Consistency |
|---|---|
| 0–25 | Dry / Earth moist |
| 25–50 | Semi-plastic / Stiff |
| 50–100 (65 mm) | Plastic |
| 100–150 | Flowing |
- 6.5 cm slump = 65 mm = plastic consistency.
- “Plastic” consistency is the target for most normal structural concrete work.