1. Walls:
- For normal Portland cement concrete without admixtures, in moderate climatic conditions (temperature between 20-30 degrees Celsius), de-shuttering of walls can be done after 24 hours for non-load-bearing walls and 48 hours for load-bearing walls.
- For concrete with accelerants or admixtures added to speed up the setting process, de-shuttering can be done earlier, typically after 12-18 hours for non-load-bearing walls and 24-36 hours for load-bearing walls.
- In cold weather (below 10 degrees Celsius), the de-shuttering time should be increased by an additional 24-48 hours to ensure adequate strength development.
2. Columns:
- Columns generally carry more load compared to walls, so they require longer de-shuttering times. For normal Portland cement concrete, columns should be de-shuttered after 48 hours in moderate climatic conditions.
- If admixtures are used to accelerate the setting process, de-shuttering of columns can be done after 36 hours.
- In cold weather, it's recommended to wait an additional 48-72 hours before removing the formwork from columns.
It's important to note that these are general guidelines, and the actual de-shuttering time may vary based on specific project requirements and site conditions. The structural engineer or project supervisor should always approve the de-shuttering schedule based on the specific circumstances of the construction project.
