QUALITATIVE ANALYSIS OF BAKED CLAY BRICKS AVAILABLE IN LARKANA REGION, PAKISTAN

Apparently in the beginning non-fired bricks were used for the shelter over the head. As the world progressed fired clay bricks found acceptability for construction. In Pakistan fired clay bricks are used in-plenty for erecting the houses. However, the technology is quite old and the practice is being repeated for several years. More commonly the bricks are porous; water absorbability is quite high and consequently the compressive strength and other properties are much lower than they should have been. In order to get an idea about quality of bricks, a comparative study of the properties of fired clay bricks of Hoofmann kiln versus Sada Bhatta (manually operated kiln) is done. A systematic study was carried out to determine various properties such as water absorption, efflorescence, crushing strength, specific weight, specific gravity of common bricks and specific weight of baked clay. This was particularly deemed imperative because of the fact that the process of burning is not uniform. This is done in two forms; i.e. by burning in the kiln with wooden logs and wooden fuels and in the Sada Bhattas where the fuel is bagasse and rice husks. Obviously it was expected that the compressive strength of bricks in the kiln was somewhat higher than Sada Bhattas. The systematic study consists of compressive strength, modulus of elasticity and Poisson's ratio as major points of investigations.