Building Materials (Cement)

                                                                         Topic: Building Materials

Facts about Cement:

•  Chemical composition of cement

                 Lime( CaO) : 62 to 67 %

                 Silica (SiO2): 17to 25%

                 Alumina (Al2O3) : 3 to 8 %

                 Calcium sulphate (CaSO4): 3 to 4%

                 Iron Oxide(Fe2O3) : 3 to 4%

                 Magnesia (MgO): 0.1 to 3%

                 Sulphur: 1 to 3 %

                 Soda and Potash: 0.5 to 1.3%

• Bogue's Compound

                C3S(Tricalcium silicate) (3CaO.SiO2) : 30 to 50%

                C2S(Dicalcium Silicate)(2CaO.SiO2) : 20 to 45%

                C3A(Tricalcium Aluminate)(3CaO.Al2O3) : 8 to 12%

                C4AF(Tetracalcium Alumino Ferrite)  ( 4CaO.Al2O3.Fe2O3): 6 to 10%           
               
        Note:

•  C3S is also called Alite

• C2S is also called Belite

• C3A is also called Celite

• C4AF is also called Felite

•  Laboratory Test for Cement

               1. Normal Consistency Test

                Apparatus : Vicat apparatus

               2. Initial and final setting time test

               Apparatus : Vicat apparatus

               3. Sondness Test

              Soundness of cement is determined by Le Chatelier's method or Autoclave test

               4. Fineness Test

             There are three methods for testing fineness
                  (a) sieve method
                  (b) Air permeability method ( Nurse and Blaine's method)
                  (c) sedimentation method or Wagner's method)

               5. Heat of hydration Test

                 Apparatus: Calorimeter

               6. Specific Gravity test

                  Apparatus: Le Chatelier's flask

               7. Tensile strength test

                     Tensile strength of cement is obtained by Briquette test

               8. Compressive strength test

                  Size of Cube Mould:  7.06 cm

          

             

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