ABSTRACT
Since massive volumes of RCC, then called “rollcrete”, was used to rehabilitate Tarbela Dam in Pakistan during a twelve year period starting in 1974, the use of RCC to remediate existing dams has been basically restricted to the United States. More than one hundred dams have used RCC to either upgrade or completely replace the existing structure. The most common use of RCC has been to increase the hydraulic capacity of existing embankment dams. By placing an RCC overlay on the downstream slope, the dam can now accommodate flood flows over the embankment safely. To date, 80 dams have used this concept called overtopping protection. RCC has also been used to provide additional structural stability for concrete or masonry dams by applying a downstream buttress to the existing structure. Many of these remediations involve improving transverse seismic stability to various types of concrete dams. In addition, RCC gravity structures have become the dam of choice for completely replacing failed or distressed dams, mainly embankment type dams. This paper will report on the applications and lessons learned from using RCC for the three main rehabilitation categories noted above in the USA.
