For walls, columns and vertical faces of all structural members, the form work is generally removed after:
Correct Answer: A. 24 to 48 hours
📚 Detailed Explanation: Vertical Formwork Removal — 24 to 48 Hours
Why A (24 to 48 hours) is correct: Vertical formwork on walls, columns, and the vertical sides of beams only holds fresh concrete in shape — it bears almost no structural load once the concrete stiffens. Current IS 456:2000 states 16–24 hours; the option “24 to 48 hours” matches the older SSC JE standard and is the closest correct answer among the choices given.
Why Vertical Formwork Can Be Removed Earlier
| Formwork Type | Load on Formwork | Min. Removal (OPC) |
|---|---|---|
| Vertical (walls, columns, beam sides) | Holds shape only — no structural load after set | 16–24 hrs (IS 456) / 24–48 hrs (SSC JE standard) |
| Soffit to slabs | Supports slab weight until props refixed | 3 days |
| Soffit to beams | Supports heavy beam weight | 7 days |
| Props to slabs (<4.5 m) | Full slab load between supports | 7 days |
| Props to beams (>6 m) | Maximum beam bending load | 21 days |
- Vertical formwork = early removal (16–48 hours) because it carries no sustained structural load.
- Horizontal/soffit formwork = longer retention because it supports the full weight of concrete above.