Formwork is the term used for the process of creating a temporary mould into which concrete is poured and formed. formwork it is a temporary support.
1)This is temporary casing is known formwork or forms or shuttering.
2) It becomes sufficiently strong to support its own weight.
3) Traditional formwork is fabricated using timber, but it can be also constructed from Steel, glass fibre, reinforced plastics and other material.
specification:-
1. Capable of resisting hydrostatic pressure of the wet concrete.
2. Join should prevent leakage of cement grout.
3. High quality workmanship and inspection necessary.
4. As light weight has possible.
5. Material used be suitable for reuse.
6.Formwork base or soffit must be capable of resisting the initial dead load of wet concrete.
7.Strong enough to withstand dead and live loads.
8.Capable of retaining its shape by being efficiently propped and braced horizontally and vertically.
9.Should be capable of being removed in various parts without damaging the concrete.
10.Should rest on a firmbase .
• Steel formwork:-
1. cost is very high.
2. reuse formworks several time.
3. It provide economicals for a large work.
4.The erection and removal of Steel formwork are simple and it prevent a smooth surface on removal.
• Timber formwork:-
1.Light in weight.
2.Cost is low.
3.It required for small work.
4.Less repetition, easily workable.
5.Easy workable with nails without splitting.
6.Free from loose konts.
• Removal of formwork:-
The operation of removing the formwork is called as stripping.
• The length of time for which of form should be kept in position depend upon the following factors:-
1.Amount and nature of dead load.
2.character and quality of concrete.
3.shape,span and situation of structure.
4. Temperature of the atmosphere.
• Slip formwork:-
A construction method in which concrete is poured into a continuous moving form.
Basically, this method involved a continuous placing of concrete into a shallow mould having a same plane as the building to be constructed.
Tt is use for tall structure such as tower, bridges , as well as horizontal structure such as roadways etc.
• Vertical slipform:-
In the vertically slip form the concrete form may be surrounded by a platform on which workers stand, placing Steel reinforcing brought into the concrete and ensure the smoothness pouring.
Together, the concrete form and working platform are raised by means of hydraulic jacks.
• horizontal slipform:-
In the horizontal slim forming for pavement, concrete is cast, vibrated, worked, and settled in place while the form itself slowly moves ahead.
Advantage of speedy construction, ability to produce a a monolithic structure and economy of operation.
