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

and curves. It shall be properly strutted and braced in at least two directions. It
shall be sufficiently tight to prevent loss of liquid slurry from the concrete. It shall
be strongly and firmly erected. The moulds shall be free from holes, open joints,
and other imperfections. The formwork shall be so arranged as to permit easy
erection initially and easy removal without jarring or disturbing the concrete finally.
Wedges and clamps shall be used wherever practicable instead of nails.
Where the depth of formwork exceeds 1.5 metres, the Contractors shall keep one
side partly open, from which the concrete could be placed and the planking on the
open side could be raised as the work proceeds. This will avoid segregation of
material in concrete and also facilitate its proper vibration.
Before concrete is placed, all rubbish shall be removed from the interior of the form
and the surfaces of the formwork in contact with concrete shall be cleaned and
thoroughly wetted. The inside surface of the formwork shall be treated with a coat
of lime, oil or any other material approved by the Engineer. Care shall be taken to
see that the above approved composition is kept out of contact with the
reinforcement. The slab centering shall be covered with “Double Wax” water
proofing paper or tar paper or polythene sheet as directed by the Engineer.
Where no special finish is desired and where form finish is acceptable, the
formwork may be prepared out of water proof black board, which shall give a good
finish to the concrete surface and thus there will be no necessity of providing
cement plaster finish. For work, which are of repetitive nature, such as column
footings, pedestals for pipes, pedestal footings; the formwork shall be fabricated out
of steel plates and structurals to obtain uniform finish throughout the work. In all
cases the formwork shall be inspected and approved by the Engineer, before any
concreting is started. The contractor shall, however, be solely responsible for the
proper design, adequacy and stability of the formwork. If at any time, in the
opinion of the Engineer, the formwork provided is not considered sufficiently rigid
and / or is defective, the contractor shall improve or strengthen the same in such
manner as the Engineer may direct. In no circumstances shall form be struck off
until the concrete attains adequate strength as required or without obtaining
permission of the Engineer. All formwork shall be removed without such shock or
vibration as would damage the concrete. Before the soffit and the struts are
removed, the concrete surface shall be exposed where necessary in order to
ascertain that the concrete has hardened sufficiently. The responsibility for the
removal of the formwork whether whole or part, shall rest, entirely with the
Contractor who must nevertheless be guided by the opinion of the Engineer in this
regard. The work of striking and the removal of formwork shall be conducted in the
presence of the Engineer and under personal supervision of a competent foreman in
the employment of the contractor.
GTS : General Technical Specification. Page 68