2. OUTLINE OF PRESENTATION
• Definition
• Classification of formwork
• Quality of formwork
• Requirements of formwork
• Formwork for building components
• Removal of formworks
• Cost of formworks
• General formwork systems
• Critical formwork systems
• Advanced formwork systems
• Case study
• References
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3. 3
Some temporary nature supports and structures are required like
Formwork (Supporting Structure)
Scaffoldings (arrangement for working plate forms)
Shoring (supporting method for unsafe structure)
Underpinning (Method of strengthening an existing structure’s footing)
4. What is formwork?
• It should be capable of carrying all imposed dead and live loads
apart from its own weight.
• Formwork is a mould including all supporting structures, used
to shape and support the concrete until it attains sufficient
strength to carry its own weight.
5. Classification of formwork
1. Classification according to sizes
2. Classification according to material
3. Classification according to nature of operation
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6. • Classification according to sizes
Small-sized formwork
-Operation by workers manually.
-Speedy work and easy operating.
-Timber and plastic
Large-sized formwork
-Crane facilities are required in the
operation.
-Reduce the number of jointing and
to minimize the number of lift.
-Steel and aluminum
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7. • Classification according to material
a) Timber
-Most popular formwork material
-Low initial cost
-High adaptability to complicated shape
-Labor intensive and environmental unfriendly
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9. b) Steel
-Initial cost is high
-Formed sections
-Heavy weight
-Suitable for large-sized panels
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10. c) Aluminum
-High quality finish.
-unskilled labour can also erect.
-Pure aluminum chemically attacked by wet Concrete
-High reuse value
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11. d) Plastic
-Unusual textures and designs can be molded into the form.
-Damages on the formwork can be easily be repaired.
-Easy to disassemble.
-Light.
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12. • Classification According to Nature of
Operation
-Manually operated formwork
-Crane lifted formwork
-Gantry, traveling and tunnel type formwork system
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13. Conventional ( Traditional ) Formwork system:
In concrete construction, formwork is commonly provided for the
following structural members.
• Foundations
• Wall
• Column
• Slabs & Beams
• Stairs
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14. Formwork for
foundation
Wall foundations
It consists of
- Plywood Sheeting
- Struts
Column Foundations
It consists of
- Side Supports
- Side Planks
- Cleats
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Cleat
Side Planks
Side Support
15. Formwork for Column :
Fig-6.1.3 Formwork for Column
•It consists of : Side & End Planks, Yokes, & Nut-Bolts
•Two end & two side planks are joined by the yokes and bolts.
• Yokes are the horizontal member which gives support to the side & end planks.
• Yokes are connected to each other by the help of nut & bolts.
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23. Formwork for Wall
It consists of
Timber sheeting
Vertical posts
Horizontal members
Rackers
Stakes
Wedges
After completing one
side of formwork
reinforcement is
provided at the place
then the second side
formwork is provided.
Vertical Posts
Struts
25. 6.1.4 Formwork for Slabs & beams
It consists of
• Sole plates
• Wedges
• Props
• Head tree
• Planks
• Batten
• Ledgers
• Beam formwork rests on head tree
• Slab form work rests on battens and joists
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36. Requirements of formwork:
Material should be cheap and reusable,
It should be practically water proof, so that it should not
absorb water from concrete,
Shrinkage should be minimum,
Strong enough to with stand all external loads,
Deflection should be minimum,
Surface should be smooth, and afford easy striping,
Light in weight, so that easy to transfer,
Joints should be stiff, so that lateral deformation and leak is
minimum . 36
37. Time of Removal of formwork:
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Sr.
No
Structural Member OPC* RHC**
1 Beam sides, walls & Columns 2-3 D 2 D
2 Slab (Vertical Supports remains intact) 4 D 3 D
3 Slab (Complete Formwork removal) 10 D 5 D
4 Beams (Removal of Sheeting, Props remains intact) 8 D 5 D
5
Beams & Arches (Complete formwork removal)
(up to 6 m span)
14 D 5-8 D
6
Beams & Arches (Complete formwork removal)
(more than 6 m span)
21 D 8-10 D
*(Ordinary Portland Cement, **Rapid Hardening Cement)
38. • Cost of formwork
For normal works cost of formwork is about 30%-40% of the
concrete cost.
For special works cost of formwork is about 50%-60% of the
concrete cost.
Formwork cost is controlled by the following factors
• Formwork Material cost
• Formwork erecting cost
• Formwork removal cost
• Formwork jointing cost (Nails and Cables)
• Labor charges.
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39. REVOLA - FRAMED WALL FORM
SYSTEM
• MESA-Revola Wall Form System is designed and manufactured for
concreting of load bearing walls and columns.
• REVOLA System is crane-dependent but admits very high concrete
pressure up to 88 kN/m2 when using suitable tie-rods of diameter
20mm.
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40. • Types of REVOLA System and Surface Material:
• Concrete facing materials differs according to demands of the
construction sites.
• REVOLA-S with Steel Plate having 4 mm thickness,
• REVOLA-P Plywood having 21 mm thickness
• REVOLA-L Composite Polypropylene Plate having 20 mm thickness
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42. • LOGICA - FRAMED WALL FORM SYSTEM
• MESA-Logica Wall Form System is crane-dependent as well as it
could be used without crane due to decreased weights of panels
having 1200 and 1500 mm height. Without taking into account of
rate of displacement of concrete, maximum 2,700 mm height of
concrete could be cast by Logica Wall Form when using tie-rods of
diameter 15mm.
• System also shortens the concreting time due to such a high resistance
to concrete pressure which reaches up to 60 kN/m2.
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43. • Types of LOGICA System and Surface Material:
• Available concrete facing materials could be two types;
• LOGICA - P with 15 mm thick Plywood
• LOGICA - L with 15 mm thick Composite Polypropylene Plate
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