Formworks are made from timber or steel, the surface in contact with the concrete being selected to give the required finish. The form work and its associated falsework must have sufficient strength to support the weight of the wet concrete without significant distortion.
There are various types of formwork in construction such as Timber Formwork, Steel Formwork, Aluminum Formwork, Plywood Formwork, Fabric Formwork, Plastic Formwork.
The cost of formwork is considered as 20 to 25% of the cost of the structure in building work, it may be higher than this in bridges. In order to reduce the cost of form, it is necessary to design economical types of formwork and to mechanize its construction.