Forms or moulds or shutters are the receptacles in which
concrete is placed, so that it will have the desired shape or
outline when hardened. Once the concrete develops adequate
strength, the forms are removed.
Forms are generally made of the materials like timber, plywood,
steel, etc.
Q.
Why camber is provided in shuttering?
Camber is provided in the formwork for horizontal members to
counteract the effect of deflection caused due to the weight of
reinforcement and concrete placed over that.
Q.
Why lubrication is required on shuttering surfaces?
Shuttering boards/Planks should be properly oiled or greased
with shuttering oil before the placement of reinforcement. The
oil film sandwiched between concrete and formwork surface not
only helps in easy removal of shuttering but also prevents loss
of moisture from the concrete through absorption and
evaporation.
Q.
When formwork should be removed?
The removal of formwork after the concrete has set is termed
as stripping. The period up to which the forms must be left in
place before they are stripped is called stripping time. The
factors affecting the stripping time are the position of the
forms, the loads coming on the elements immediately after
stripping, temperature of the atmosphere, the subsequent loads
coming on the element etc. As a guideline, with temperature
above 20 degree following time limits should be followed:
