Study of Durability of Concrete by Partial Replacement of Cement by Hypo Sludge and Fly Ash
CHAPTER 01
INTRODUCTION
1.1 FLY ASH
India produces about 70 million tons of coal ash per year from burning about 200 million tons of coal per year for electric power generation. Coal-ash management posses a serious environmental problem for India and requires a mission-mode approach. Considerable research and development work have been undertaken across the country towards confidence building and developing suitable technologies for disposal and utilization of fly ash construction industries. At present about 10% ash is utilized in ash dyke construction and land filling (a technology developed and pioneered at IIT Kanpur) and only about 3% of ash is utilized in other construction industries. This is very much in contrast with 80% or more fly ash used in developed countries for the manufacture of bricks, cellular concrete blocks, road construction, land fill application, ceramics, agriculture, insulating bricks, recovery of metals and cenospheres and dam constructions. Currently, about one acre per MW of land is needed for ash disposal. Several pilot projects were undertaken in recent years to demonstrate the bulk utilization of fly ash specifically for Indian conditions. Also, it has been successfully demonstrated that fly ash can be utilized in major construction projects such as dams, ash dyke, landfills, roads and pavements, soil stabilization and for other purposes such as brick manufacture, cement industry, tiles, and paint industry. Realizing the large scale generation of fly ash, it’s very low utilization, the Government of India set up the fly ash Mission under the Department of Science & Technology at New Delhi for coordinating all such effort. A law has also been enacted in 1999 projecting 100 per cent utilization of fly ash within a stipulated period and making it mandatory to use flash for the purpose of road construction, bricks etc. within a radius of 50 km from coal based thermal power plants.
INTRODUCTION
1.1 FLY ASH
India produces about 70 million tons of coal ash per year from burning about 200 million tons of coal per year for electric power generation. Coal-ash management posses a serious environmental problem for India and requires a mission-mode approach. Considerable research and development work have been undertaken across the country towards confidence building and developing suitable technologies for disposal and utilization of fly ash construction industries. At present about 10% ash is utilized in ash dyke construction and land filling (a technology developed and pioneered at IIT Kanpur) and only about 3% of ash is utilized in other construction industries. This is very much in contrast with 80% or more fly ash used in developed countries for the manufacture of bricks, cellular concrete blocks, road construction, land fill application, ceramics, agriculture, insulating bricks, recovery of metals and cenospheres and dam constructions. Currently, about one acre per MW of land is needed for ash disposal. Several pilot projects were undertaken in recent years to demonstrate the bulk utilization of fly ash specifically for Indian conditions. Also, it has been successfully demonstrated that fly ash can be utilized in major construction projects such as dams, ash dyke, landfills, roads and pavements, soil stabilization and for other purposes such as brick manufacture, cement industry, tiles, and paint industry. Realizing the large scale generation of fly ash, it’s very low utilization, the Government of India set up the fly ash Mission under the Department of Science & Technology at New Delhi for coordinating all such effort. A law has also been enacted in 1999 projecting 100 per cent utilization of fly ash within a stipulated period and making it mandatory to use flash for the purpose of road construction, bricks etc. within a radius of 50 km from coal based thermal power plants.