Basic concept of cement and boguh's compound

it content basic subjects related to cement composition

1. PRESENTATION ON IMPORTANCE OF BOGUE’S COMPOUND AKARSH

2. CEMENT Cement is a powdery substance made by calcining lime and clay ,mixed with water to form mortar or mixed with sand , gravel, and water to make concrete Types of cement 1. Rapid hardenging Cement 2.heat cement 3. Sulphates resisting cement 4.Blast furnace Slag cement 5.High Alumina Cement 6.White Cement

3. Types of cement 7. Coloured C ement 8. Pozzolanic Cement 9. Air Entraining Cement 10. Hydrographic Cement 11. Ordinary portland Cement

4. Composition of ordinary portland cement oxide % content cao 60-67 sio2 17-25 Al2O3 3.0-8.0 Fe2O3 0.5-0.6 MgO 0.1-0.4 SO3 Alkalies (K2O,Na2O) 1.3-3.0 0.4-1.3

5. 1.LIME ( CaO ) :- Sufficient quantity of silica should be present in cement to dicalcium and tricalcium silicate. Silica imparts strength to cement Presence of lime in a sufficient quantity is required to form silicates and aluminates of calcium. Deficiency in lime reduces the strength of cement. Deficiency in lime causes cement to set quickly. Excess lime make cement unsound. Excessive presence of lime cause cement to expand and disintegrate. 2.Silica (Sio2) :-

6. 3.ALUMINA (Al2O3) :- Impart the quick setting time Act as Flux Lowers the clinker temperature Excess :- Excess alumina weaken the cement. 4 . MAGNESIA: MAGNESIUM OXIDE(MGO) :- Magnesia should not be present more than 2% in cement. Excess magnesia will reduce the strength of the cement.

7. 5. Iron oxide (Fe2O3) :- Iron oxide imparts color to cement . It acts as a flux. At a very high temperature it imparts into chemical reaction with Calcium and Aluminum to form tricalcium aluminoferrite. Tricalcium A luminoferrite imparts Hardness and strength to cement 6 . Calcium Sulfate ( CaSO4) :- This is present in cement in the form gypsum(CaSO4.2H O) It slows down or retards the setting action of cement .

8. 7. SULFATE (SO4) :- Should not be present more than 2%. Excess Sulfur Trioxide causes cement to unsound. 8. ALKALINE: Should not be present more than 1%. Excess Alkaline matter causes efflorescence.

9. CEMENTS – COMPOSITION Name Formula Shorthand Weight % Tricalcium silicate ( Alite ) 3 CaO . SiO2 C3S ~55-60 Dicalcium silicate ( Belite ) 2 CaO . SiO2 C2S ~15-20 Tricalcium aluminate 3 CaO . Al2O3 C3A ~5-10 Tetracalcium aluminoferrite 4 CaO . Al2O3 Fe2O3 C4AF ~5-8 Gypsum CaSO4. 2H2O CSH2 ~2-6

10. Determines the physical and mechanical Characteristics of the cement Determines its chemical activity Determines its scope of use Determines the cost IMPLICATIONS OF COMPOUND COMPOSITION

11. 1) TRICALCIUM ALIMUNATE (C3A) :- 3 TO 14% High heat evolution Formed with in a day Early strength 210 cal/gm- ----3days 310 cal/gm-----90day Heat of hydration

12. 2)TETRACALCIUM ALUMINOFERRITE (C4AF) Formed within day influence on color (Dark color) ; so it is less used in white concrete (1 % to 2 %) only Contributes little strength Low temperature Heat of hydration 70 cal/gm------3 days 100 cal/gm- --90 days

13. 3) TRICALCIUM ALUMINATE (C3A):-(45%-65%) Formed within a weak Early strength of concrete 50%-60% strength to concrete Heat of hydration is 120 cal/gm 4)DICALCIUM ALUMINATE (C2A):-(15%-35%) It take year to form Progressives strength to cement Heat of hydration is 62 cal/gm

14. PORTLAND CEMENT TYPES (ASTM C150) Type I – Normal (OPC) Type II – Moderate Sulfate Resistance Type III – High Early Strength Type IV – Low Heat Of Hydration Type V – High Sulfate Resistance

15. Type 1

16. ASTM Type 2 &4

17. ASTM Type 3

18. ASTM Type 5

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