Concrete exposed to hot water springs - It’s designing and monitoring post construction performance - A case study

To full fill country’s irrigation and power requirements various large capacity dams have been constructed on major rivers in last 50 years. 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 concrete 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 projects for enhancing their sustainability. Water plays an important role in the production of concrete. 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 measures 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 study discusses the details of such problems and the suggested remedial measures for Nathapa Jhakri Hydroelectric power project, Himachal Pradesh, India.