A brief overview on Non conventional concrete technologies like Self compacting concrete,Green concrete etc.
A good topic for technical presentation on Civil Engg.
3. Conventional Concrete
Conventional concrete is a conglomerate of hydraulic (Portland) cement , sand, stone, and water. It
was developed approximately 150 years ago to imitate natural stone while providing less labor-intensive
methods of shaping the material
6. DEVELOPMENT OF SELF-COMPACTING
CONCRETE
durability of concrete structures in Japan
durable concrete structures sufficient compaction skilled workers
Gradual reduction in skilled workers Requirement of new technology proposed by
Okamura in 1986
It is a ‘High performance Concrete’ due to its high durability
7.
8. Important Properties & Benefits
Self-compactability
Avoidance of bleeding and segregation
Low shrinkage
Low permeability
Strength as needed
Safer, quieter sites
Better appearance
9. What is the secret?
Optimum Paste Viscosity and water content which is attained by one of three means:
High cement content
High content of Fly Ash, Silica Fume etc.
Use of Viscosity Modifying Admixture
Low water content using HRWR High Strength
10. REQUIREMENTS OF
CONSTITUENT MATERIALS
CEMENT
Typical cement content – 350 to 450 kg/m3.
Cement > 500kg/m3 →shrinkage
Cement < 300kg/m3 →Requires Extra fine fillers
AGGREGATE
Fine Aggregate
Coarse AggregateFly ash: In appropriate quantity may be
the added the quality
11. REQUIREMENTS OF
CONSTITUENT MATERIALS
Other
Silica fumes: Added to improve the mechanical properties of scc.
Stone powder: finely crushed lime stone,dolomite or granite added to increase the powder content.
Fibres: fibres may be used to enhance the properties of scc as same as normal concrete
20. Green Concrete
oFirst invented in Denmark in the year 1998 Kyoto Protoclol
oMade with concrete wastes
oSustainable Construction
21. ADVANTAGES OF GREEN CONCRETE
Reduced CO 2 emissions.
Low production costs.
Saves energy, emissions and waste water.
Helps in recycling industry wastes.
Reduces the consumption of cement overall.
22. o Better workability.
o Sustainable development.
o Greater strength and durability than
normal concrete.
o Compressive strength and Flexural
behavior is fairly equal to that of the
conventional concrete.
23. SUITABILITY OF GREEN CONCRETE IN STRUCTURES
Improve damping resistance of building.
speed of construction, shorten overall construction period.
Reduce the dead weight of a facade from 5 tons to about 3.5 tons.
Good thermal and fire resistance, sound
insulation than the traditional granite rock
27. High strength concrete
strength in excess of 60MPa
ultra high performance concrete (UHPC) will more usually contain cement replacement
materials and a high-range water-reducer (HRWR) or superplasticiser(SP
29. Conclusion
Concrete that is a little more expensive per cubic meter to buy
BUT
It will require less skill and effort to place
It will look better with no appearance defects
It will be more durable
It will require more skill at the batching plant
30. References
o Journal of Advanced Concrete Technology Vol . 1 , No . 1 , 5 - 1 5
(Self Compacting Concrete)
o Edvardsen Ing. Carola and Tølløse Karsten (2001). Environmentally
“Green” Concrete Structures
o Benjamin A. Graybeal, and Joseph L. Hartmann(2003). STRENGTH
AND DURABILITY OF ULTRA-HIGH PERFORMANCE CONCRETE