Formwork and its types on the basis type of constructionArticles > Formwork and its types on the basis type of construction
A mould, mold, moulding, or molding is a casing formed by a rigid frame of wood, plastic, or metal, in which liquid concrete or other pliable material is poured for giving it a definite shape and design. Formwork is the name of a temporary or permanent mold in which pliable material like liquid or liquid concrete for the sake of shaping and designing it. A liquid concrete can not sustain itself due to the flowing nature of liquid concrete, it is impossible for a liquid to sustain its shape. Therefore, in construction work, rigid frames and boxes are used to keep the shape of the concrete maintain until it dries up and becomes able to maintain its form. These boxes and frames are made up of wood, steel, plastic, or other types of metal and rigid material. Before going through the discussion of types of formwork, we need to clarify, first the difference between, formwork and molding, and shuttering and formwork.
Difference between Shuttering and Molding:
Mold/ mold is the shaping and designing frame used to design the liquid concrete until it dries and becomes able to sustain itself while shuttering refers to the method of forming a mold. The kind of material is used for making a mold, is included in shuttering. The method or technique used to form a molding is included in shuttering. In short shuttering is the method of making a framework for concrete, while a mold is a framework made by means of shuttering to shape the concrete.
Difference between Shuttering and Formwork:
Generally, both the terms, formwork and shuttering are used to describe the process of making molds. Mould is the space in which concrete is poured and let for hardening. The difference between shuttering and formwork is, a shuttering refers to the method of forming the molds by means of plywood, steel panels, wooden logs, and boards, whereas, formwork is used for a broader meaning. Formwork is the whole process of installing the shuttering and scaffolding and other means and techniques used to form the molding.
Now we come to our main theme of the topic which is “The types of a Formwork”.
Types of Formwork on the basis of the type of construction:
We have classified the formwork into four types regarding the type of structure to be constructed.
• Beam Formwork: In civil engineering work, there is rarely a construction in which the beam has not been used. A beam is the most important element of the construction of the RCC framed structure. A beam formwork consists of side sheeting panels and bottom sheeting panels of a prefabricated material.
• Wall Formwork: The use of Wall formwork is carried out during the construction of the RCC wall or shear of the walls of dams, basements, and wing walls. Wall shuttering of plywood and timber/lumber are vertically arrange up to form a mold to be filled with the concrete material of the wall.
• Foundation Formwork: The design of a foundation formwork depends upon the design and shape of the foundation which is to be constructed. Whatever the shape and design of the foundation is, the formwork is also designed in a similar shape. During the construction of the foundation, only the side sheeting is arranged with the vertically arranged panels. The bottom of the foundation does not need any formwork, because the bottom of the foundation is already set over the surface.
• Column Formwork: The design of formwork arranged for a column depends on the column outline. The column outline may be rectangular, circular and hexagonal, or any other shape. The formwork of the column is constructed according to the dimensions of the column. There is a foot rim, anchored in soil, which holds the panels of shuttering.
• Tunnel Formwork: A tunnel formwork is constructed in the form of an inverted L. The tunnel formwork allows the constructor to cast walls and slabs in one operation in a daily cycle. The result is a cellular reinforced structure, the surfaces of which are sufficiently high quality to require only minimal finishing for direct decoration, while the end walls and facades are easily completed with thermally insulated units that can be clad as required.
The system creates an efficient load-bearing structure for use in a wide variety of applications. It is particularly effective in projects suited to repetitive cellular construction such as residential blocks, hotels, student accommodation, barracks, and prisons.
Requirements of a good formwork:
Good formwork should have the following basic characteristics.
1. A formwork must be strong and stable which could sustain the load of concrete. Otherwise, weak formwork may destabilize and deform the concrete structure.
2. Should be tight so that liquid concrete may not leak. A leaking grout out of concrete weakens the strength of the structure and produced cracks in it.
3. A successful formwork should allow being dismantled with the desired sequence without damaging the concrete structure.
4. The material used in the formwork should be low cost, easily available, and affordable.
5. The used material of the formwork should be re-usable and durable.
6. It should be set accurately to the desired shape and design of the mold.
7. It should be light as much as possible, so that it may easily be handled.
8. The formwork material should not deform in case of exposing it to sunlight and water.
9. It should be able to be set on a firm and leveled plane surface.
10. A good formwork must have high-quality workmanship and regularly scheduled for inspection.
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