58814894-geopolymer.ppt

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WELCOME

Transcript of 58814894-geopolymer.ppt

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WELCOME

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GEO POLYMER CONCRETE(Concrete without cement)

Guided by Presented by

Manju PM Bonu PrathapLecturer S7 CivilSNGCE Reg. No.

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What’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.

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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

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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.

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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.

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Preparation of geopolymer concrete

GeopolymerisationStorage

Aggregate

Fly ashAlkaline activatorNaOH + Na Silicate

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2.Geopolymer Concrete :Process

• Alkaline 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.

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MANUFACTURE OF

GEOPOLYMER CONCRETE

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The aggregates are prepared in saturated-surface-dry (SSD) condition, and are kept in plastic buckets with lid

Dry Materials of Geopolymer Concrete

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The fly ash and the aggregates are first mixed together dry in 80-litre capacity pan mixer

. Pan Mixer Used in the Manufacture of Geopolymer Concrete

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The liquid component of the mixture is then added to the dry materials and the mixing continued usually

for another four minutes

Addition of Liquid Component

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The fresh concrete could be handled up to 120 minutes without any sign of setting and without any degradation in the

compressive strength

Fresh Geopolymer Concrete Ready for Placing

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The workability of the fresh concrete was measured by means of the conventional slump test

Slump Measurement of Fresh Geopolymer Concrete

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Boundary between Geopolymer binder , aggregate and reinforcement

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ADVANTAGES

Cutting the world’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.

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4.Applications of GPC

• Pre-cast concrete products like railway sleepers,electric power poles etc.

• Marine structures

• Waste containments etc..

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• Different source materials

• Properties of soluble silicate

• Contaminants

• Industry regulations

• New material

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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.

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