Partially replace the cement in concrete Ex: HIGH VOLUME FLY ASH CONCRETE Develop alternative material Ex: Geopolymer concrete
Portland cement production is a major contributor to CO2 emissions as an estimated 5 TO 8 %of all human- generated atmospheric CO2 worldwide comes from the concrete industry. Production of Portland cement is currently topping 2.6 billion tons per year worldwide and growing at 5 percent annually.
Geopolymer concrete has the potential to substantially curb CO2 emissions produce a more durable infrastructure capable of design life measured in hundreds of years conserve hundreds of thousands of acres currently used for disposal of coal combustion products protect aquifers and surface bodies of fresh water via the elimination of fly ash disposal sites.
OPC vs GEO POLYMERGeopolymer concrete (GPC) using “flyash”Greater corrosion resistance,Substantially higher fire resistance (up to2400° F),High compressive and tensile strengthsRapid strength gain, and lowershrinkage.Greenhouse gas reduction potential asmuch as 90 percent when compared withopc.
Hardened cementations 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.
Source materials : Alumina-silicate Alkaline liquids combination of sodium hydroxide (NaOH) or potassium hydroxide (KOH) and sodium silicate or potassium silicate.
Alkaline activatorFly ash NaOH + Na SilicateAggregate Geopolymerisation Storage
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.
. Pan Mixer Used in the Manufacture of Geopolymer Concrete
Addition of Liquid Component
Fresh Geopolymer Concrete Ready for Placing
Slump Measurement of Fresh Geopolymer Concrete
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.
Pre-cast concrete products like railway sleepers, electric power poles, parking tiles etc. Marine structures due to resistance against chemical attacks Waste containments( fly ash) FUTURE use IN MAJOR PROJECTS
• Different source materials• Properties of soluble silicate• Contaminants• Industry regulations• New material• Lack of awareness.
The compressive strength of GEOPOLYMER concrete is about 1.5 times more than that of the compressive strength with the ordinary Portland cement concrete, for the same mix. Similarly the Geopolymer Concrete showed good workability as of the ordinary Portland Cement Concrete.
Non toxic, bleed free Sets at room temperature Long working life before stiffening Impermeable Higher resistance to heat and resist all inorganic solvents Higher compressive strength
The exposure of the geopolymers materials to the NaCl solution resulted in the consistent increase in the compressive strength during the whole period of measurement (720 days) and the values were as high as 70 Mpa Almost no corrosion products could be found on the surface of the geopolymer
A GEOPOLYMERS mortar after the 1.5-year exposure to thesolutions of NaCl
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 environmentsLow-calcium fly ash-based geopolymer concrete has excellent compressive strength and is suitable for Structural applications.