Formwork or Shuttering
Formwork or shuttering may be defined as the set of forms provided to keep the concrete in position until it sets.
How formwork or shuttering is provided ?
- Formwork or shuttering is provided as per standard specifications.
- Inner surface of the shuttering plates should be oiled to prevent concrete sticking to it.
- Before concrete is laid, Base and formwork should be watered by sprinkling water over its surface.
- In general, shuttering should not be removed before 14 days.
- 4 days for R.C.C. columns, 10 days for roof slab, and 14 days for beams.
- However sides can be removed after 3 days of concreting.
- Shuttering should be removed slowly and carefully without disturbing and damaging concrete.
- Centering and shuttering should be made with timber or steel plate.
- These plates should be close and tight to prevent any leakage of concrete.
- Gap between these plates should be filled with necessary props, bracings and wedges.
- Formwork should be sufficiently strong and stable enough and should not yield on laying concrete.
- They should be removed gradually without disturbing the concrete.
- A coat of oil should be applied or paper should be spread to have a smooth and finished surface.
- Oil is applied to prevent adherence of concrete.
- For slab and beam, small camber should be given in centering.
- For example, for 2.5 meter or 10 feet. 1 cm or half inch camber should be provided with the maximum of 4 cm or 1.5 inch.