Introduction of Concrete

                             Cement And Admixtures  

Manufacture of Portland Cement:

                 The Raw materials required for manufacture of Portland cement are calcareous materials like limestone or chalk and argillaceous materials like shale and clay.

                 The Process of manufacture of cement consists of grinding of raw materials ,mixing  them intimately in such certain proportions depending upon their purity ,composition and burning them in kiln at temperature of about 1300-1500 C.At this Temperature materials sinters  and particularly fuss to form modular shaped kilnker is cooled and grounded in to fine powder with addition of about 2-3% Gypsum .There are two process known as 

• Wet
• Dry Process.

Depending upon the weather,mixing and grinding of raw materials is done wet or dry in condition.

With the little change in the above process we have to do semi dry process also,where the raw materials are ground dry and hen mixed with about 10-14% of water and further burst kilnkering temperature.

Chemical Compostion of Cement:

            The Raw materials used for manufacturing of cement consists of mainly of lime,silica,aluminium and iron oxide.These oxides interact with one another in kiln  to form compler compounds.