Review on the Use of both Fly-Ash and Pond-Ash in Concrete Mix Design

In today’s Era energy planners are aiming to increase the use of Oil, Gas, Nuclear and also Renewable Energy sources to meet the electricity demand in India. But till now coal-based thermal power plants are the major source of electricity generation and they will continue to dominate in the next few decades too. One of the major disadvantages of coal-based thermal power plants is the disposal problem of Fly Ash. It was earlier considered as a total waste and an environmental hazard, thus its use was limited, without much understanding. Fortunately, its useful properties have now begun to be known as raw material for various applications. Fly ash from the thermal plants is available in large quantities in fine and coarse form. Fine fly ash is used in construction industry in some amount and coarse fly ash is subsequently disposed over land in slurry forms. In India around 165 MT fly is produced and only around 40% of that is being utilized in different sectors. Balance fly ash is being disposed over land. It needs one acre of land for ash disposal to produce 1MW electricity from coal. Fly ash and pond ash utilization helps to reduce the consumption of natural resources. The fly ash became available in coal based thermal power station in the year 1930 in USA. For its gainful utilization, scientist started research activities and in the year 1937, R.E. Davis and his associates at university of California published research details on use of fly ash in cement concrete. This research had laid foundation for its specification, testing & usages. This study reports the potential use of pond-ash as a replacement for sand and fly-ash as cement in concrete mixes. The study investigated the effect of waste pond-ash as partial replacement of fine aggregates in various percentages, on concrete properties such as mechanical (compressive strength, splitting tensile strength and flexural strength) and durability characteristics (rapid chloride penetration and deciding salt surface scaling) of the concrete. This paper deals with the review of literature for fly-ash and pond-ash as partial replacement of cement and fine aggregates in concrete.