Roller compacted dam concrete (RCD) technology : B. J. Selva Mora, Individual Studies by Participants at the International Institute of Seismology and Earthqauke Engineering, 31, 1995, pp 201–216

Abstract

The use of rolled concrete was limited to the subbase of roads and airfield pavements, being called lean concrete or dry lean concrete. This kind of concrete became popular due to the fact it is a simple material to produce and place. This concrete has a low cement content, about 110 to 120 kg/m 3 (1) , and uses washed aggregate of concreting quality. According to some researchers, the rolled concrete gravity dam is the most economical solution between the high-volume earthfill dam and the lesser volume conventional concrete gravity dam (1) . The use of lean concrete for dams has generated both RCC (roller compacted concrete) and RCD (roller compacted dam concrete) dams. RCC dams have developed mainly in the USA, being a good example Willow Creek Dam, completed in 1983. This dam was widely known to seek complete economy, although it was necessary to use grouting in order to reduce a large amount of leakage through it. In the case of RCD dams, unique for Japan, in 1976 a full scale test was made at the cofferdam of Okawa Dam, which proved that RCD was applicable to the dam body. The first RCD dam was Shimajigawa Dam ( 317 000 m 3 ), completed in 1980, followed by Tamagawa Dam (1 150 000 m 3 ). Roller compacted concrete dams have the advantages of economical and rapid construction of embankment dams and structural reliability of concrete dams. The concrete is placed in continuous layers and is consolidated by vibrating rollers. Conventional concrete is placed in isolated monoliths and consolidated by immersion vibrators. RCC and RCD methods are characterized by reduced labor costs, continuous construction, shortened construction periods and cement content savings (1) .