(Concrete Without Cement)
Rajesh Kumar Nayak
• HOW TO PREPARE
1) Geo polymer concrete is nothing but a
replacement of cement concrete.
2) Cement is not used as binding materials.
3)Fly ash and alkali solution is used as binder.
4)It gives early strength
5)High compressive strength
6)Reduces co2 emission
What is wrong with cement concrete??
• Many concrete structures deteriorate after 20
• 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
How to reduce the use of cement?
• Partially replace the use of cement in concrete.
example: high volume fly ash concrete
• Develop alternate materials.
What is geopolymer Concrete ?
• Hardened cementitious paste made from
flyash and alkaline solution.
• Combines waste products into useful
• Setting mechanism depends on
• Curing temp is between 60-90 degree
Source materials :
Alkaline liquids :
combination of sodium hydroxide
(NaOH) or potassium hydroxide
(KOH) and sodium silicate or
Preparation of geopolymer concrete
NaOH + Na Silicate
2.Geopolymer Concrete :Process
• Alkaline solutions induce the Si and Al atoms in
the source materials ,example fly ash , to
• Gel formation is assisted by applying heat.
• Gel binds the aggregates ,and the unreacted
source material to form the Geopolymer
The aggregates are prepared in saturated-surface-dry
(SSD) condition, and are kept in plastic buckets with
The fly ash and the aggregates are first mixed together
dry in 80-litre capacity pan mixer
The liquid component of the mixture is then added to the
dry materials and the mixing continued usually for
another four minutes
Fresh Geopolymer Concrete Ready for Placing
The fresh concrete could be handled up to 120 minutes
without any sign of setting and without any degradation
in the compressive strength
Cutting the world’s carbon.
The price of fly ash is low.
Better compressive strength.
Excellent properties within both acid and salt environments.
4.Applications of GPC
• Pre-cast concrete products like railway sleepers,electric power poles
• Marine structures
• Waste containments etc..
• High cost of alkaline solution
• Practically steam curing is difficult
• Bringing of source material to location
• Industry regulations
• New material
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
Geo polymer 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.