Question

What is the composition of Portland cement? What is the average composition of good quality cement?

Answer 1

Hint : Portland cement is the most common type of cement found and used all around the world. Portland cement is one of the key factors for the formation of concrete. This Portland cement is generally best for its low heat of hydration.

Complete Step By Step Answer:
Cements are actually the structural binding force. Cement sets the material to give its perfect, compact and well defined shape. It is the building block of our houses, industries, supermarkets etc.
So, Portland cement is a type of a cement with a particular composition that defines its structural, physical and chemical properties.
Portland cement can be defined as a fine powder produced by the heating of the limestone and the clay particles.
So, now let’s have a look at the composition of the Portland cement:
Portland cement consists of the
 $
  CaO = 50\% - 60\% \\
  Si{O_2} = 20\% - 25\% \\
  A{l_2}{O_3} = 5\% - 10\% \\
  MgO = 2\% - 3\% \\
  F{e_2}O = 1\% - 2\% \\
  S{O_2} = 1\% - 2\% $
Hence, this is the composition of the Portland cement which defines its good qualities and makes it suitable for the production of concrete.
Also, standardising the compositions of the certain compounds in the cement can improve its quality to many folds.
Hence, the average composition of good quality cement is:
The ration between the silica i.e. $ Si{O_2} $ And $ A{l_2}{O_3} $ should be between $ 2.5 - 4.0 $
The ratio of lime $ (CaO) $ to the silicon oxide, $ Si{O_2} $ aluminium oxide, $ A{l_2}{O_3} $ and iron oxide, $ F{e_2}O $ should be close to $ 2 $ .
Therefore, the answer is very much clear.

Note :
Portland cement is the most famous and worldwide used cement and it is especially used in all forms of concrete. Portland cement itself can be divided into five types. Among these five types of Portland cement, the most famous and good quality is ordinary Portland cement (OPC).