Fly ash, Lime calcined gypsum and sand, with requisite quantity of
Water is mixed in proper proportions which produces slow setting
Cement, the resultant mass pressed is in to bricks of any desired strength. These bricks can be used in building constructional activities instead of common burnt clay bricks. These bricks are lighter in weight and stronger than common burnt clay bricks. The generation of fly ash in India by thermal power stations is more than 100 million tones per annum (in December 2010). One kilogram of coal of fired yields fly ash ranging from 200 to 500 grams. At present only 6% fly ash being utilized.
180 billion tones of common burnt clay bricks are consumed annually. Approximately 340 billion tones of clay – about 5000 acres of top layer of soil dug out for bricks manufacture. Soil erosion, and emission from coal burning or fire woods which causes deforestation are the serious problems posed by brick industry. The above problems can be reduced some extent by using fly ash bricks in dwelling units.
Demand for dwelling units likely to rise to 80 million units by
year 2015 for lower middle and low income groups, involving an
Estimated investment of $670 billion, according to the Associated
Chamber of Commerce and Industry (Assocha). Demand for dwelling
units will further grow to 90 million by 2020, which would requires a
minimum investment of $890 billion. The Indian housing sector at
present faces a shortage of 20 million dwelling units for its lower middle and low income groups which will witness a spurt of about 22.5 million dwelling, units by the end of Tenth plan period. There is ample scope for fly ash brick and block units.
So by using this type of bricks we not only conserve our environment from degradation, also made a positive step to preserve our precious top soils.