Development of light weight building blocks using bottom ash from coal fired thermal power plants

Abstract

Self-weight of building units, construction time and sound workmanship are key factors affecting the quality and cost effectiveness of masonry construction. Amongst the loads a structure should resist, self-weight is a major component thus the reduction of self-weight by introducing lightweight material would effectively reduce the load as well as the cost of construction. Furthermore, large individual units would help speedy construction and results in cost reduction. Yet, it is difficult to achieve sound workmanship in construction of masonry works without skilled workers. By having interlocking blocks, requirement of skilled workers can be reduced. Hence an experimental investigation was carried out to develop interlocking lightweight cement blocks, contrary to those existing, to address the above mentioned requirements. The interlocking hollow blocks developed are 600mm x200mm x200mm in size with a weight of 20 kg. The expanded polystyrene beads have been used to reduce the self-weight. Experimental investigation has shown that average compressive strength of block was 4.91N/mm2 and wall panel strength was 2.13 N/mm2, therefore it can be used for load bearing masonry walls. It was also observed ductile load deformation behaviour at the failure of the masonry wall panel, which is an added advantage.