Civil Engineering Today

  Tests for cement   1. Field tests 2. Laboratory tests   1. Field tests of Cement - Following tests may be carried out in the field : A.      Colour B.      Physical properties C.      Presence of lumps D.     Strength E.      Date of Packing   A. Colour - The colour of cement should be uniform. It should be typical cement colour i.e. grey colour with a light greenish shade. This is not not always a reliable test. But it gives an indication of excess lime or clay and the degree of burning. B. Physical properties - Cement should feel smooth when touched or rubbed in between fingers. If the hand is inserted in a bag or heap of cement, it should feel cool and not warm. If a small quantity of cement is thrown into the water, it should float some time before finally sinking. Then, it should sink and should not float on the surface. A thin paste of ...

  Manufacturing process of Cement Cement manufacturing process involves various raw materials and processes. Cement is a greenish grey coloured powder, made of calcined mixtures of clay and limestone. When mixed with water becomes a hard and strong building material. It was first introduced by a British stone mason , Joseph Aspdin in 1824, who cooked cement in his kitchen. He heated a mixture of limestone and clay powder in his kitchen, and grind the mixture into powder creating cement, that hardens when mixed with water. Cement is first used in the tunnel construction in the Thames River in 1828. Calcareous and argillaceous raw materials are used in the manufacture of Portland cement. The calcareous materials used are cement rock, limestone, marl, chalk and marine shell. The argillaceous materials consist of silicates of alumina in the form of clay, shale, slate and blast furnace slag.   There are four stages in the manufacturing process of cement: 1. Mixing of raw material 2...

  Types of Cement - 1.       Ordinary Portland Cement (OPC) 2.       Portland Pozzolana Cement (PPC) 3.       Rapid Hardening Cement 4.       Quick setting cement 5.       Low Heat Cement 6.       Sulfates resisting cement 7.       Blast Furnace Slag Cement 8.       High Alumina Cement 9.       White Cement 10.   Colored cement 11.   Air Entraining Cement 12.   Expansive cement 13.   Hydrographic cement Fig: Different types of cements 1. Ordinary Portland Cement (OPC) - Ordinary Portland cement is also called Portland cement because on hardening and its colour resembles to rocks near Portland in England. It was first of all introduced in 1824 by Joseph Asp din, England. Ordinary Portland cement is the most extensive...