Geopolymer concrete
-
Upload
civil-engineers -
Category
Education
-
view
12.445 -
download
36
description
Transcript of Geopolymer concrete
![Page 1: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/1.jpg)
![Page 2: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/2.jpg)
2
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.
![Page 3: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/3.jpg)
3
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
![Page 4: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/4.jpg)
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.
![Page 5: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/5.jpg)
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.
![Page 6: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/6.jpg)
Preparation of geopolymer concrete
GeopolymerisationStorage
Aggregate
Fly ashAlkaline activatorNaOH + Na Silicate
![Page 7: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/7.jpg)
5
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.
![Page 8: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/8.jpg)
MANUFACTURE OF
GEOPOLYMER CONCRETE
![Page 9: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/9.jpg)
The aggregates are prepared in saturated-surface-dry (SSD) condition, and are kept in plastic buckets with lid
Dry Materials of Geopolymer Concrete
![Page 10: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/10.jpg)
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
![Page 11: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/11.jpg)
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
![Page 12: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/12.jpg)
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
![Page 13: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/13.jpg)
The workability of the fresh concrete was measured by means of the conventional slump test
Slump Measurement of Fresh Geopolymer Concrete
![Page 14: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/14.jpg)
Boundary between Geopolymer binder , aggregate and reinforcement
![Page 15: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/15.jpg)
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.
![Page 16: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/16.jpg)
7
4.Applications of GPC
• Pre-cast concrete products like railway sleepers,electric power poles etc.
• Marine structures
• Waste containments etc..
![Page 17: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/17.jpg)
• Different source materials
• Properties of soluble silicate
• Contaminants
• Industry regulations
• New material
![Page 18: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/18.jpg)
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.
![Page 19: Geopolymer concrete](https://reader033.fdocuments.in/reader033/viewer/2022061221/54bf34cf4a795920498b46a8/html5/thumbnails/19.jpg)
For more Paper Presentations on Civil Engineering topics visit the following site..