Concrete technology

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. 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.

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

4. 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

5. 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

6. Slump test to test workability
6

7. 7
Cube test to test the strength

8. It is a mold used to shape the concrete and support the
concrete until it attains sufficient strength to carry its
own weight.

Formwork system

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
Progress
Wooden
posts
(ballies)
A network of
wooden beams
to support the
sheathing
System formwork in Progress
Collapsible
type props
(CT props)
A network of
wooden H-beams
to support the
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