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Functions of Cement Manufacturing Constituents.

  Lime (CaO) Lime forms nearly two-thirds of the cement. Therefore sufficient quantity of the lime must be in the raw materials for the manufacturing of cement. Its proportion has an important effect on the cement. Sufficient quantity of lime forms Dicalcium silicate and tri-calcium silicate in the manufacturing of cement. Lime in excess, causes the cement to expand and disintegrate.     Silica (SiO 2 ) The quantity of silica should be enough to form di-calcium silicate and tri-calcium silicate in the manufacturing of cement Silica gives strength to the cement. Silica in excess causes the cement to set slowly. Alumina (Al 2 O 3 ) Alumina supports to set quickly to the cement. Lowers the clinkering temperature. Alumina in excess reduces the strength of the cement. Iron Oxide (Fe 2 O 3 ) Iron oxide gives colour to the cement. Magnesia (MgO) It also helps in giving colour to the cement. Magnesium in excess makes the cement unsound Calcium Sulphate (or) Gypsum (CaSO...
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Field test

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Field tests on cement are carried to know the quality of cement supplied at the site. It gives some idea about cement quality based on colour, touch and feels and other tests. Tests on Cement at the Construction site: Colour test: The colour of the cement should normally be greenish-grey. Presence of lumps: Due to the moisture from the atmosphere, cement develops lumps. But it’s not good to use that for construction.  Open the bag and take a good look at the cement. There should not be any visible lumps Adulteration test: This test is performed by feeling the cement with fingers. It should feel smooth when rubbed in between fingers.  If it feels rough, it implies that the cement is adulterated with sand. Temperature test: This test involves inserting the hand in the bag to check its temperature. It must be giving you a cool feeling. If it’s warm inside, then it indicates that the process of hydration is taking place. Float tests: This test consists of throwing a handful of ce...
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Test conducted on cement

 There are two major tests conducted on cement: Field Test Laboratory test    Field Tests Field tests on cement are carried to know the quality of cement supplied at the site. It gives some idea about cement quality based on colour, touch and feels and other tests. Laboratory Tests Laboratory tests are required to confirm the Indian Standard Specifications. Tests are :  Fineness test,  Standard consistency test Setting time tests,  Soundness tests,  The heat of hydration tests, Chemical composition tests.
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