1. Erection Of Form Work Presented by : Christopher Brown Ramasan linton Aniff Grant

2. WHAT IS FROM WORK ? Formwork for in-situ concrete work may be described as a mould or box into which wet concrete can be poured and compacted so that it will flow and finally set to the inner profile of the box or mould.

3. The formwork structure must take account of any beams, lintels and openings. It should be strong and stable so that it can support the weight of people and plant.

4. SOME REQUIREMENTS FOR A SUCCESSFUL FORMWORK It should be strong enough to support the load of wet concrete, which is generally considered to be approximately 2400 kg/m3

5. It must not be able to deflect under load, which would include the loading of wet concrete, self-weight, and any superimposed loads such as operatives and barrow runs over the formwork.

6. It must be accurately set out; as concrete is a fluid when placed, it will take up the shape of the formwork, which must therefore be of the correct shape, size and in the right position.

7. It must have grout-tight joints. Grout leakage can cause honeycombing of the surface, or produce fins, which have to be removed. The making-good of defective concrete surfaces is both time consuming and costly. Grout leakage can be prevented by using sheet materials and sealing the joints with flexible foamed polyurethane strip or by using a special self-adhesive tape.

8. Form sizes should be designed so that they are the maximum size that can easily be handled by hand or by a mechanical lifting device.

9. Material must be chosen so that it can be easily fixed using double-headed nails, round wire nails or wood screws. The common method is to use nails, and these should be at least two-and-a-half times the thickness of the timber being nailed, in length

10. The design of the formwork units should be such that they can easily be assembled and dismantled without any members being trapped

11. ERECTING THE FORMWORK STEP ACTION Use the working drawings to establish the level of the underside of the floor slab. This becomes the level of the top of the formwork deck.

12. Put up the supporting framework of props, ledgers and joists and nail the formwork deck to the joists. Level the entire structure by adjusting the wedges and nail diagonal braces across the props to stiffen them.

13. Inspect the deck for open joints and fill the gaps with building paper or other material. Treat the deck with an oil, which will make it easier to remove the formwork when finished.

14. Attach the electrical conduits for the first floor wiring and ceiling lights for the room below to the formwork. This work should be done by an electrician. Attach any pipes for other services to the formwork.

15. TYPICAL BEAM SLAB FORMWORK

16. DIMENSION & ALIGNMENT According to Collins dictionary the alignment of something is its position in relation to something else or to its correct position. While a dimension is a measurement such as length, width, or height. If you talk about the dimensions of an object or place, you are referring to its size and proportions.

17. IMPORTANCE OF ALIGNMENT WHEN ERECTING FORMWORK Form designs must consider conditions such as unsymmetrical placement of concrete, impact from machine delivered concrete, uplift, and concentrated loads produced by storing supplies on the freshly placed slab.

18. Rarely will there be precise information as to loads that will come on the forms, and the designer must make some safe assumptions which will hold good for conditions generally encountered.

19. Forms are essentially molds that are filled with concrete to form building structures such as columns or to cast stiffeners, belting and lintels the demensions of said forms directly influence the shape and or proportions of concrete to its final

20. hardened shape, thus dimensions of are one of the most important factors that affect the erection of forms, if a form was not erected with the correct dimensions it could lead to the failure of a structure or to the wastage of material.

21. Similarly in regards to the alignment of forms they are as important as the dimensions because, like dimensions the inaccuracies of the placement when not aligned correctly could result in the wastage of material caused if the form wasn't aligned

22. correctly in order to create a water tight seal between the ends or seams of the forms, issues regarding alignment in the form could also result in the deformation of the concrete with the end product being warped or not proportionate.

23. Hence due to the dimensions and the alignment of a form being so vastly important, when erecting formwork these factors are seen as being invaluable.

24. END OF PRESENTATION