Concrete is a widely used construction material consisting of cement, water, and aggregates. The strength of concrete is specified using its 28-day cube strength in N/sq.mm. Formwork is used to mold wet concrete into desired shapes and allow it to cure. Formwork design involves choosing traditional or systematic approaches using wood or steel components like props, beams, sheathing to form columns, walls, and beams until the concrete gains sufficient strength. Proper formwork is important for quality concrete finish and structural integrity.

1. Concrete
• One of the very important and widely used
material in construction
• The Grade of the concrete is specified by its 28
day’s cube strength (E.g. M20 means the cube
strength is 20 N/sq.mm)
• Concrete used on works is specified according
to IS 456 (2000).
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2. •Consists of Portland cement, water, and aggregate ( Fine&
Coarse )
•Cement, water and fine aggregate – mortar
-Admixtures added for specific purposes like
– Entrain numerous microscopic air bubbles
– Retard the initial set of the concrete
– Waterproof the concrete , etc.
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3. Concrete chain
Cement supply sand supply Coarse aggregate Water supply
supply
Transporting, unloading and stacking
Gauging
Mixing Slump test
Cube test
Transporting
Placing
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Compaction Curing

4. PROPORTIONING CONCRETE MIXTURES
• For successful utilization, the mixtures must be properly
proportioned ( Mix design )
Concrete Mix Design-IS 10262
Designed to achieve a defined
• workability
• strength
• durability
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5. BATCHING AND MIXING OF CONCRETE
MATERIALS
• Batching is weighing or volumetrically measuring and
introducing into the mixer the ingredients for a batch of
concrete
• A batch is the quantity of concrete mixed at one time
More accurate to measure by weight
• As per IS 4925 : 1968 - specification for concrete batching
and mixing
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6. Slump test to test workability
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7. Cube test to test the strength
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8. Formwork system
It is a mold used to shape the concrete and support the
concrete until it attains sufficient strength to carry its
own weight.

9. Introduction
 No desirable structure can be built without the use
of formworks.
 Such is the importance of formwork that it constitutes
30% of Cost 60% of Time
Construction
 Apart from that the quality of concrete finish and
soundness of concrete depends very much on the
formwork system.

10. Types of Formwork
Formwork can be divided into two approaches :
 Traditional approach
 Systematic approach (System formwork)

11. Traditional formwork system in System formwork in Progress
Progress
Collapsible A network of
Wooden A network of
type props wooden H-beams
posts wooden beams
(CT props) to support the
(ballies) to support the
sheathing.
sheathing
Pictures and sketches taken from L&T- DOKA formwork manuals

12. Column Formwork
Pictures and sketches taken from L&T- DOKA formwork manuals

13. Wall Formwork
Pictures and sketches taken from L&T- DOKA formwork manuals

14. Beam Forming Support
Pictures and sketches taken from L&T- DOKA formwork manuals