Cement

cementum: In the most general sense of the word, a cement is a takeer, a substance which designates and hardens independently, and can withstand other materials together. The volcanic ash and pulverized brick additives which were added to the burnt linden tree to obtain a hydraulic binder were later referred to as cement. Cements used in construction be characterized as hydraulic or non-hydraulic. The most important use of cement is the wall plug of mortar and concrete. Composition of Cements The essential raw ingredients of Portland cement are limestone, 60 to 65%, alumina (A12O3) 4 to 8% te dioxide (SiO2) 20 to 25%, Ferrous Oxide (Fe2O3) 2 to 4 % and atomic number 12 Oxide (MgO) 1 to 3%. The alumina and silica are unremarkably found combined as clay, which is a silicate of aluminum (Al2O32SiO2) + 2H2O. all(prenominal) last(predicate) cements contain other ingredients due to the essential materials non macrocosm elegant in nature and from contact with fuel in calcinations. both(prenominal) of these accidental ingredients may improve the cement, others are sluggish and clean except that they exist in such mensuration as to displace essential ingredients, and others are positively harmful, if resign in quantity, because of the chemical action they produce. There are accidental ingredients usually amounting to about 5%, but these must not implicate everyplace 1.75% anhydrous sulphuric acid (So3), nor over 3% of magnesia (MgO).

Excess of clay causes a cement to set quickly, while excess of lime causes it to set easy or imperfectly. Iron oxide gives cement its color. T ypes of Cement 1. hydraulic cement ! 2. Non-hydraulic Cement 3. Ordinary portland cement 4. rapid hardening cement 5. full(prenominal) alumina cement 6. Low heat cement 7. cursorily setting cement 8. Portland pozzolana cement 9. Blast furnace cement 10. uninfected cement 11. Colored cement 12. Sulphate resisting cement 1. hydraulic Cement Major application of hydraulic cement is for the parable of concrete and mortar. It bonds the aggregate to...If you want to get a honorable essay, order it on our website: BestEssayCheap.com

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