👉Possible Reasons for Removing Column Formwork at 8 Hours

💫1. Rapid-Hardening (High Early Strength) Concrete Was Used

⏺If the contractor used rapid-hardening cement (RHC) or an accelerator admixture, the concrete can gain enough strength in 6–8 hours to allow formwork removal.

🏷Example:

⏺Quick setting concrete
⏺Concrete with calcium nitrate/calcium chloride accelerators
⏺Special high-early-strength mix

💫2. Very High Temperature Curing Conditions

⏺In hot climates, concrete gains strength faster.
⏺If the temperature is 30–35°C+, the surface concrete may harden quicker, sometimes allowing earlier removal.

💫3. Contractor Working Under Time Pressure or Poor Planning

⏺Sometimes the contractor removes formwork early to:

*reuse formwork
*push schedule
*continue work above

⏺This is not a valid technical reason and is risky.

💫4. Very Light Formwork (Only Side Panels)

⏺For columns, removing only the side panels earlier is possible because the column carries no load from above at this stage.

⏺But 8 hours is still too early unless concrete strength is verified.

❌ Why It Is Usually NOT Allowed

⏺Removing formwork at 8 hours may cause:

*surface damage / honeycombing
*corners chipping
*loss of shape
*structural weakness if strength is too low

⏺Concrete normally needs: 5–7 MPa minimum strength before column formwork removal
⏺Usually achieved at 24 hours, not 8.

✅ Correct Professional Answer

🚧Formwork removal at 8 hours is only acceptable if the concrete is high-early-strength or contains an accelerator and if strength has been verified.

⏺Otherwise, it is not recommended and can damage the column.

@etconp