Harmful Ingredients in Brick-earth

Harmful Ingredients in Brick-earth :

            1. Alkalis : Alkalis present in the brick earth lower the fusion temperature abnormally making the brick deform and twist. In addition, alkalis have hygroscopic properties. They absorb water from atmosphere and make the walls damp resulting into unhealthy atmosphere and weaker structure.  In addition, when the moisture in the wall evaporates, they leave behind white or gray spots spoiling the appearance of the building. This effect is called ‘Efflorescence effect’.

            2.  Lumps of Lime :  If these are present, as explained earlier, on heating get converted into quick lime. This quick lime in the presence of water is highly brittle and the brick crumbles.

            3.  Pebbles of stones :  In the presence of these, there is hindrance in molding the brick. In addition, the bricks cannot be cut to the required size, if needed, while erecting the wall.

            4.  Organic matter :  Organic matters like roots, leaves etc. burn while the brick is burnt producing CO2. This Carbon dioxide creates porosity in bricks affecting the strength of bricks. Hence, organic matter should be avoided in brick-earth.

            In addition to these above mentioned impurities,  Iron pyrites, Kallar or Reh  [ Sodium Sulphate + Sodium Chloride ] also have harmful effects on bricks like that of  lumps of lime and organic matter respectively.