WATER QUALITY IMPACT ON THE DAM CONCRETE FOR UPCOMING PUMPED STORAGE SCHEME IN WEST BENGAL

The construction of large capacity dams on major rivers in the country is required to full fill country’s irrigation and power requirements. The long term sustainability of these structures is largely dependent on hydro - environment and the capacity of these structures to resist weathering action, chemical attack, abrasion, or any other process of deterioration. The co ncrete deterioration is directly influenced by various geographical, climatic and ecological conditions. These are therefore the major factors to be considered during the designing and construction of the upcoming river valley projects. Water plays an important role as the chemical reactions between cement and water enable the setting and hardening of cement, resulting in a binding medium for the aggregates and development of strength. Concrete can be made which will perform satisfactorily when exposed to various atmospheric conditions, to most waters and soils containing chemicals etc. There are, however, certain aggressive conditions under which the useful life of even the best concrete will be short. Understanding these conditions permit m easures to be taken to prevent or reduce deterioration. Peculiar problems like deterioration of concrete due to poor water quality, problem of leaching of lime in seepage galleries, high temperature of water springs inside head race tunnels etc. have been encountered during the pre and post construction investigations at various projects. The present paper highlights the pre construction stage water quality studies for three seasons to evaluate its possible effect on conc rete along with suggested remedial measures for upcoming Turga Pumped Storage Scheme, West Bengal, India.