New Technologies for Rapid Dam Construction

The accelerated economic growth in China and a few South Asian countries is one of the key drivers of mega hydel projects to harness rivers and generate power and future demands of electricity. Mass concrete with large aggregates makes up the concrete of such mega-dams. Typically this is a low slump concrete – about 2 to 4 cm - and requires a significant amount of compaction, intensive labour and time to complete. With traditional vibratable dam concrete enhanced to Roller Compacted Concrete (RCC) – originating in Japan during the late‘70s, this reduced the time by about 15 – 20%.

To meet the deadlines for power generating companies or clients, the need of the hour is to enable construction at a rapid pace and at the same time meet durability criteria for concrete under various climatic/geographical conditions. Today, this is possible with advanced concrete technologies aided with special admixture technologies to help accelerate and sustain speed of construction. These revolutionary admixtures enable other distinct advantages – lower cementitious content in concrete to help in reducing heat of hydration in mass concrete as well improve quality of paste (improving impermeability) and provide super flowability (in certain cases) - all of which help to increase service life of the dam.

This paper provides an overview into two “paradigm-shifts” – one in enhancing conventional Roller Compacted Concrete (RCC) become vibration sensitive and generate better paste quality to respond faster to the vibratory rollers and in the long run enable faster completion of an RCC dam; the other is a revolutionary step in enabling a ultra-low fines self consolidating concrete with 120 mm aggregates for rapid dam placement (referred to here as Speed Dam Technology)