formwork centering and scaffolding by khalid

knowledgeable thing in presentation by khalid. about formwork, scaffolding and centering.

1. Formwork, centering and scaffolding Subject teacher: shahbaz sir Created by:- Shaikh K halid, Shaikh I rfan, Khan M ujahid Ansari H anzala , Khan M asiullah

2. Introduction Formwork or shuttering and types of it and new technics or new technology of formwork. Centering is hardly similar to formwork or shuttering, and types of centering. Scaffolding and many types of it.

3. It is a temporary structure used to support a work crew and materials to aid in the construction. Maintenance and repair of buildings, bridges and all other man made structures. There are four major types of scaffolding. Brick-layers or single scaffolding, Mason’s scaffolding or double scaffolding, Needle scaffolding or cantilever. Steel scaffolding. Scaffolding:-

4. In this type of scaffolding includes a single framework of ledgers, standard and putlogs. In this case standards are placed at 2 to 2.5m interval. This scaffolding is commonly employed for bricklaying . Brick-layer or single scaffolding

5. Mason’s or double scaffolding This type of scaffolding is commonly provided in case of stone masonry because it is very difficult to make holes into the wall for giving the grip to putlogs. In such scaffolding independent framework is done with standards, ledgers, putlogs are firmly tied to ledgers. For better stability, framework is supported by rackers.

6. Tis type of scaffolding is used if, Ground is weak to support the standards, Construction is done in busy street or road, Construction of upper part of the wall is to be done. In such case, needles are supported by strut which is commonly fixed at opening. Needle or cantilever scaffolding

7. Steel scaffolding A steel scaffolding is quite similar to timber scaffolding, only difference is that material used in such scaffolding is steel instead of timber. Erection of this scaffolding is rather fast and it can also dismantle rapidly. Lashings are here replaced by steel couples or fittings. Its initial cost is more, but it can be used for longer period. Only drawback is that, it is heavy to transport from one placed to another, skilled labour is required for erection and dismantling.

8. Formwork and Centering Form work : All arrangement done to support the green concrete till it attains the strength is known as form work or temporary work. Form work determines the geometry , shape. size and finish of the form work . Types of formwork: Timber formwork, Plywood formwork, Steel formwork, S-formwork. Requirement for good formwork.

9. Timber formwork: The timber is the most widely used and universally adopted formwork material. It is cheaper, easily available, easy to fix, impact resistant, easy to remove, can be used several number of times, can give larger level surface and can be used to obtain any geometrical shape. Sheeting for slab, beam, column side and beam bottom. 25mm to 40mm thick Joints and ledges 50 x 70mm to 50 x 250 mm Posts 75 x 100 mm to 100 x 100mm

10. Plywood formwork:- Most common material use for facing panel. Easily cut to shape on site. It can be used many times. Thinner plywood used to facilitate bending. The main advantage is that large panel surface are available. The fixing of forms is rapid and economical. It does not warp, swell and shrink during the setting of concrete. It has high impact resistance.

11. Steel formwork:- Steel formwork are commonly employed for big project, where the forms are to be repeatedly used. They give smooth surfaces needing very little finishing. These prove to be economical and are best suited for circular columns and flat slab construction. Generally, we can say that: They are easy to assemble. Gives smooth surface. High strength and impact value. For big project if produced on large scale they are economical otherwise highly costed .

12. Aluminum formwork(MIVAN):- Aluminum formwork system is a comparatively new technology in India. it saves cost, times and improve the quality of the construction. It is strong and light easy to handle. It suitable when:- mass housing, Typical floors, Fast construction required, Column less structure.

13. Advantage of aluminum formwork:- Aluminum does not rust like steel, therefore a aluminum formwork can be reused hundreds of times. Formwork is made with an aluminum alloy which has high tensile strength and is also very hard. Doesn’t required timber or plywood for construction activities, so its save the environment .

14. Part of formwork which support the horizontal surface is called as centering. Example:- beam bottom and slab etc. It is also used for bottom surface of sunshade. Centering:-