Immersion Vibrated RCC

摘要

Roller-Compacted Concrete (RCC) technology has replaced in many cases the traditional way of building concrete dams,which was based on the use of Conventional Vibrated Concrete(CVC).This development is mainly motivated by lower construction costs of RCC compared with CVC dams.However,from beginning,in-situ quality has been a point of controversy.The concrete mix(or combination of mixes) used in some RCC dams,has not achieved the level of performance which is typically required in concrete dams,namely: density,strength,impermeability and durability.A new mass concrete mix which is in the limit range of consistency between CVC and RCC has been developed recently.This concrete is called Immersion Vibrated-Roller Compacted Concrete (Ⅳ-RCC) and,when designed and placed in the dam following certain specifications and construction procedures,the same mix is suitable for consolidation either by traditional immersion vibration or by roller compaction.This finding has brought major simplifications in the design and construction of modern concrete dams.Both,quality and economy are derived from this simplicity.Details of Ⅳ-RCC materials,typical mixture proportions,construction,and dam design benefits are discussed in this article.In addition,application of Ⅳ-RCC in several dam projects is presented.These experiences show that the end product has similar quality,if not better,than traditional mass concrete that was used in dam construction before RCCs broke into the dam world.