No abstract

Opencast mining accounts for about 86% of the produced coal in India. Most of the opencast mines in the country use bulk emulsion explosives. The total consumption of explosives in India is around 550,000 tonnes annually. It has been shown that detonation velocities vary with the density of the emulsion explosive. Here we describe experiments that have been conducted to understand the influence of velocity of detonation of emulsion explosives on fragmentation of blasted muckpile over a range of densities. The density of explosives was varied from 0.6 to 1.1 g/cc which resulted in the variation of detonation velocity from 3262 to 4624 m/s.

No abstract

The use of activated fly ash in blended cement and sintered fly ash aggregate in concrete as a partial replacement of granite aggregate has been examined .The concrete so formed is light in nature(upto 40% reduction in unit weight)and development of such concrete minimises consumption of granite rock resulting in the protection of natural environment. Present investigation considers M20 and M25 grade concrete It is observed that with partial (20%,30% and 40% by volume)replacement of natural granite aggregate by sintered aggregate the physical properties of concrete such as compressive strength and Young's modulus of elasticity are retained.