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).
1

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.
2

3. Concrete chain
Cement supply sand supply Coarse aggregate Water supply
supply
Transporting, unloading and stacking
Gauging
Mixing Slump test
Cube test
Transporting
Placing
3
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
4

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
6

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