PACKAGE : I Bid Document VOLUME : II - Public Health Engineering

8.3 Removal of Forms and Shoring.
Formwork shall be so designed as to permit easy removal without resorting to
hammering or levering against the surface of the concrete. The periods of time
elapsing between the placing of the concrete and the sticking of the formwork shall
be as approved by the Engineer after consideration of the loads likely to be imposed
on the concrete and shall be in any case be not less than the periods shown below,
depending on the ambient temperature.
1. Vertical surfaces of wall 1 day
2. Columns & vertical sides of beams 2 days
3. Slab bottoms with props left under 7 days
4. Beam bottom with prop left under 7 days
5. Removal of props under slabs
Span upto 4.5 m 7 days
Span over 4.5 m 14 days
6. Removal of props to beam and arches
Span upto 6.0 m 14 days
Span over 6.0 m 21 days
Sequence of striking formwork shall be approved by the Engineer.
Not withstanding the foregoing, the contractor shall be held responsible for any damage
arising from removal of formwork before the structure is capable of carrying its own
weight and any incidental loading. The contractor shall be wholly responsible for
repairing or reconstruction as directed by the Engineer the section of the works so affected.
Shoring and False work Removal:
In retaining wall construction shoring and false work shall not be removed until
21 days after concrete placement or until concrete has attained at least 90 percent of
the 28 days design compressive strength as demonstrated by control test cylinders,
whichever is earlier.
GTS : General Technical Specification. Page 69