08-02-2010, 07:34 AM
[attachment=1803]
GEO POLYMER CONCRETE-Concrete without cement
Whatâ„¢s wrong with cement concrete?
Many concrete structures deteriorate after 20 years.
Cement production releases high amounts of CO2 to the atmosphere(1tonne of cement production releases 1tonne of CO2) thus contributing to 7% of world CO2 emissions.
Cement is one of the most energy intensive material.
How to reduce the use of cement
Partially replace the use of cement in concrete.
example: high volume fly ash concrete
Develop alternate materials.
example:Geopolymer concrete
Geopolymer Concrete
Hardened cementitious paste made from flyash and alkaline solution.
Combines waste products into useful product.
Setting mechanism depends on polymerization.
Curing temp is between 60-90 degree celcious.
CONSTITUENTS OF GEOPOLYMER CONCRETE
Source materials :
alumina-silicate
Alkaline liquids
combination of sodium hydroxide (NaOH) or potassium hydroxide (KOH) and sodium silicate or potassium silicate.
2.Geopolymer Concrete
rocessAlkaline solutions induce the Si and Al atoms in the source materials ,example fly ash , to dissolve.
Gel formation is assisted by applying heat.
Gel binds the aggregates ,and the unreacted source material to form the Geopolymer concrete.
ADVANTAGES
Cutting the worldâ„¢s carbon.
The price of fly ash is low.
Better compressive strength.
Fire proof.
Low permeability.
Eco-friendly.
Excellent properties within both acid and salt environments.
4.Applications of GPC
Pre-cast concrete products like railway sleepers,electric power poles etc.
Marine structures
Waste containments etc..
Conclusion
The reduced CO2 emissions of Geopolymer cements make them a good alternative to Ordinary Portland Cement.
Produces a substance that is comparable to or better than traditional cements with respect to most properties.
Geopolymer concrete has excellent properties within both acid and salt environments
Low-calcium fly ash-based geopolymer concrete has excellent compressive strength and is suitable for Structural applications.
