Submitted by N. Samba siva (y09ce097) J. Sai chand (y09ce080) K. Praveen(y09ce086) P. Manohar(y09ce104) Under the guidance of K. Divya(y09ce081) Smt T.SUJATHA,M.TECH

GEO POLYMER CONCRETE The term geopolymer was coined by

Davidovits in 1978. This inorganic alumino silicate polymer is synthesized from predominantly silicon and aluminium material of geological origin or by-product materials such as fly ash, chemicial composition of geopolymer materials are similar to Zeolite.

The fly ash which has high content of Silica (Si) and Alumina (Al) reacts with alkaline solution like Sodium hydroxide(NaOH) and Sodium Silicate (Na2SiO3) and forms a gel which binds the fine and coarse aggregates. Geo polymer concrete do not require any water for matrix bonding, instead the alkaline solution react with Silicon and Aluminium present in the flyash. The polymerisation process involves a substantially fast chemical reaction under alkaline condition on SiAl minerals.

ADVANTAGES OF GPC The price of fly ash is low. Better compressive strength than opc Fire proof. Low permeability. Eco-friendly. Excellent properties with in both acid and salt

environments. It reduces CO2 emissions and make them a good alternative to Ordinary Portland Cement.

APPLICATIONS OF GPC Pre-cast concrete products like

railway sleepers, electric power poles etc. Marine structures .

ECONOMIC BENEFITS 10 25 % cheaper than that of portland cement

concrete 1 tonne fly ash can produce 2.5 m3 of GPC 1 tonne fly ash earns one carbon-credit

MAIN CONSTITUENTS OF GPC Source Materials: Fly ash, Silica fume, Slag, Rice-

husk ash, Red mud, etc. Alkaline Liquids: Sodium hydroxide with sodium silicate,Potassium hydroxide with potassium silicate. (It is used to induce the silicon and aluminum atoms in the source materials to dissolve and form a gel )

MATERIALS USED FOR GPC Fly ash Coarse aggregate Fine aggregate and Robo sand Sodium hydroxide solution Sodium silicate solution

Cera- hyperplast xr-w40

FEATURES OF FLY ASH Higher strength Decreased permeability Reduced shrinkage and heat of hydration Improved workability and finishing Reduced segregation

Cheaply available material

PHYSICAL AND CHEMICAL PROPERTIES OF OPC AND FLY ASHPROPERTYSio2 Cao AL2O3 Specific gravity General use in concrete

PORTLAND CEMENT 21 62 5.66 3.15 Primary binder

FLY ASH CLASS F 52 5 24. 2.38 Cement replacement

FLY ASH FACTSJust one tonne of fly ash use equals: Conserved Landfill Space Enough for 455 days of solid waste produced by an average Indian. Reduced CO2 Emissions Equal to two months of emissions from an automobile Saved Energy Enough to provide electricity to an average Indian home for 24 days.

TESTS ON FINE AGGREGATE Specific gravity:2.60 Fineness modulus :3.27

WHAT IS ROBO SAND?

Robo sand is crushed aggregates produced from hard granite stone which is cubically shaped with grounded edges, washed and graded with consistency to be used as a substitute of river sand

WHY ROBO SAND IS USED? Availability of River Sand is low The Government contemplating ban on dredging of River beds to quarry river sand, as part of the

growing concern for environment protection The most preferred alternative to river sand is the Robo sand

ROBO SAND The grade of the robo sand used is Zone II The robo sand contains flat bottomed edges The sand used is grey in colour

The sand used is passed through 600 micron sieve Specific gravity of Robo sand is 2.713

ADVANTAGES OF ROBO SAND Acquires higher strength It provides a superior shape It consists of a proper gradation of fines

It has a smooth surface texture It does not contain any impurities It is an eco friendly material

TESTS ON COARSE AGGREGATES Specific gravity:2.89 Fineness modulus:7.20

PREPARATION OF SOLUTION The molecular weight of sodium hyd0xide(NaoH) is 23+16+1 For obtaining 8 molarity of sodium hydroxide 320

gms (8*40=320) of sodium flakes are dissolved in 1 liter of distilled water

Same procedure is followed for preparation

of 14 molarity solution here 560 gms (14*40) were used The solution is prepared 1 day before casting of cubes

Mix proportions From previous studies two trail mixes were obtained i.e

Mix-I : 1:1.35:3.17 Mix II :1:1.39:3.20 Our required target strength is obtained through Mix II So Mix-II is adopted for our studies By keeping the mix proportions constant molarities have been varied

TRAIL MIXES.Materials Tail mix-1 (KG/M3) Trail mix-2 (KG/M3)

Coarse aggregates

20mm12mm

914406 408 554

914406 408 554

Fly ash Fine aggregates

Sodium hydroxideSodium silicate Super plastizer Molarity

70130 20 8 molatity

70130 10 14 molarity

Six cubes are casted for determining the

compressive strength of geopolymer concrete in order to design the optimum mix. The size of each cube is 100*100*100.Molarity 8 14 Compressive strength(N/mm2) 18 25

Here the compressive strength in case of 14

molarity solution is more .So trail mix 2 from the experimental programme is considered as optimum mix

OPTIMUM MIXMATERIALS COARSE AGGREGATES 20mm 12mm FLY ASH FINE AGGREGATES SODIUM HYDROXIDE SODIUM SILICATE MIX -2 (kg/m^3)

914 406 408 554 70 130 10 14

SUPER PLASTIZERMOLARITY

COMPARISION OF SLUMPConventional concrete The slump value of

Geo polymer concrete The obtained Slump value

medium grade conventional concrete as per code provision is 50-100 mm

of geo polymer concrete with fine aggregate is 135 mm Where as the slump value of geo polymer concrete with robo sand is 140 mm

EXPERIMENTAL PROGRAMME CASTING:

Three cubes were casted for 7 days of size 150*150*150 mm and same were casted for 28 days with fine aggregate and robo sand Three cylinders were casted for 7 days and same were casted for 28 days with fine aggregate and robo sand

.

CURING:

sunlight curing is done for the cubes and cylinders at a temperature of 25-30 degrees Other than sunlight curing steam curing or oven curing can also be provided A temperature of around 70-80 degrees is provided for the steam curing for 24 hours to attain compressive strength of 28 days

TEST RESULTS FOR FINE AGGREGATE:S.NO COMPRESSIVE STRENGTH OF CUBE (MPa) 7 DAYS 1 2 3 4 5 6 22.5 21.75 22.10 _ _ _ 28 DAYS _ _ _ 29.28 28.27 28.73 TENSILE STRENGTH OF CYLINDER (MPa) 7 DAYS 7.84 7.14 8.5 _ _ _ 28 DAYS _ _ _ 10.19 9.28 11.05

TEST RESULTS FOR ROBO SAND:S.NO COMPRESSIVE STRENGTH OF CUBES (MPa) 7 DAYS 1 2 3 4 19.8 19.6 20.2 _ 28 DAYS _ TENSILE STRENGTH OF CYLINDERS (Mpa) 7 DAYS 5.88 6.02 5.90 _ 28 DAYS _ _ _ 8.4

_ 25.74

5 6

_ _

25.48 26.26

_ _

8.6 8.43

CONCLUSIONS GPC attains higher early strength than conventional

concrete Density of GPC is similar to that of OPC Slump value of GPC with fine aggregate is less than GPC with robo sand Higher concentration of NaOH solution results in higher strength The compressive strength of GPC with river sand is more than GPC with robo sand at 28 days Split tensile strength of GPC with river sand is more than GPC with robo sand at 28 days Split tensile strength is more than OPC

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