Strength Characteristics of Pond Ash Mixed With Polypropylene Fibre

Pond ash is a by-product obtained from Thermal Power Plants due to burning of coal. It is a mixture of Fly ash and bottom ash which is deposited in slurry form in ash ponds. India’s electricity demands are met through Power plants of which most are coal based. Based on some estimation 73 % power plants are coal based from which huge tonnes of Pond ash are generated every year. Disposal of these waste products is a big nuisance and poses threat to environment. Disposal in Pond ash in ash ponds not only causes loss of agricultural land which could provide food to human and animal race, it also renders the land unfit for future use. Because of large amount of Pond ash generation, large amount of land is increasingly being used for its diposal which is posing serious threat to food security. Hence the need of the hour is to look for alternative ways to utilise this by product. The present study is based on the effective utilisation of Pond ash in geotechnical field and its replacement as conventional earth material. The geotechnical characteristics of compacted Pond ash were evaluated using Polypropylene fibres. Polypropylene fibres of 6 mm, 12 mm and 19 mm length were used in 0.5 %, 1 % and 1.5 % of dry weight of Pond ash and their effect on strength characteristics of Pond ash were studied. The effect of fibre reinforcement on compacted density was studies using heavy compaction test. The stress strain behaviour of Pond ash using triaxial tests (unconsolidated undrained) was performed. The results showed increase in ductility of pond ash due to fibre inclusion and also increase in peak deviator stress. Higher strength were obtained in 19 mm fibres but keeping the economical and ease of handling issues in mind 12 mm fibres showed encouraging results. It can be safely concluded that Pond ash can replace conventional earth materials.