A Presentation by

Chander Shekhar Tanwar (09-ITMG-1409-IT) Deeksha Agrawal (09-ITMG-1413-IT)

First used in the 19th century A strong binder/bonding agent Cement comes from opus caementicium (masonry in Greek)

Portland cement clinker is a hydraulic material which shall consist of at least two-thirds by mass of calcium silicates (3CaO.SiO2 and 2CaO.SiO2), the remainder consisting of aluminium- and iron-containing clinker phases and other compounds. The ratio of CaO to SiO2 shall not be less than 2.0. The magnesium content (MgO) shall not exceed 5.0% by mass.Definition byEuropean Committee for Standardisation

OxidesFormulaPercentageLimeCaO60-67SilicaSiO217-25AluminaAl2O33-8Iron OxideFe2O30.5-6.0MagnesiaMgO0.1-4.0Sulphur Trioxide SO31-2Soda & PotashNa2O + K2O0.5-1.3

CompoundFormulaPercentageTricalcium Silicate3CaO.SiO245Dicalcium Silicate2CaO.SiO225Tricalcium Aluminate3CaO.Al2O310Tetracalcium Aluminoferrite4CaO.Al2O3.Fe2O310

Dry Process: Raw materials are crushed, dried and then ground to a fine powder form.Wet Process: Raw materials are crushed. Then, they are ground and washed in the presence of water. (Slurry)

The raw mixture is heated in a cement kiln with temperatures ranging up to a peak of 1400-1450 C. A complex succession of chemical reactions take place as the temperature rises. This results in formation of clinker.CaCO3 CaO + CO22CaO + SiO2 2CaO.SiO23CaO + SiO2 3CaO.SiO23CaO + Al2O3 3CaO.Al2O3 4CaO + Fe2O3 +Al2O3 4CaO.Al2O3.Fe2O3

The cooled clinker is passed onto tube mills, where it is ground to fineness which is decided according to the quality/class of the product. 2% of Gypsum is added to control the process of hardening.

Calcareous MaterialRotary KilnSlurry/PowderCementArgillaceous MaterialClinker (cooled)Ball and Tube MillMillGypsum (CaSO4.2H2O)

It is the chemical combination of cement and water which continues at a great speed at first and goes on reducing gradually.3CaO.Al2O3 + 6H2O 3CaO.Al2O3.6H2O + 3CaO.Al2O3 + CaSO4.2H2O + xH2O 3CaO.Al2O3.CaSO4.yH2O3CaO.SiO2 + xH2O 2CaO.SiO2.(x-1)H2O + Ca(OH)2 + 2CaO.SiO2 + xH2O 2CaO.SiO2.xH2O4CaO.Al2O3.Fe2O3 + 7H2O 3CaO.Al2O3.6H2O + CaO.Fe2O3.H2O

Manufacture of concrete Construction of brick buildingsPre-cast unitsRoad FurnitureCement mixed with water leads to a highly alkaline solution (pH~13)Cement leads to pollution in the form of dust, gases, noise and vibration.

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