Grout enriched RCC: The past and future in the USA

Grout Enriched RCC (GERCC) refers to the process of adding grout to the surface of traditional RCC and using internal vibration to create a homogeneous facing material similar to traditional conventional concrete. The process is traditionally used at the upstream and downstream faces of RCC dams, but has also been used for consolidation near rock abutments and around imbedded waterstops and dam penetrations. The benefits of GERCC include its simplicity, efficiency, low cost, and relatively low permeability. Since its inception at the Yantan Dam cofferdam in China in 1987, GERCC has become the mostly widely used facing system in China and has been used extensively on several large dams internationally. Notable GERCC projects over the past few years include the Sharpei Dam (132 m high) in China, the Cine Dam (135 m high) in Turkey, the Meil I Dam (188 m high) in Columbia and the Ralco Dam (150 m high) in Chile.

In the United States, the use of GERCC has been very limited. GERCC was first used to a limited extent on the Atlanta Road Dam in Cobb County, Georgia and an experimental test section was constructed using GERCC on the North Fork Hughes River Dam in West Virginia. At Olivenhain Dam in San Diego Co., California, GERCC was used to provide a relatively flat surface for the installation of a liner system on the upstream face.

This paper will explore the reasons why GERCC has not been successful in the limited domestic applications to date. In particular, the paper will compare the RCC mix designs used domestically with limited success with those used internationally with marked success. Various grout proportions, equipment, placement arrangements, and vibration techniques will be compared and evaluated. Furthermore, the paper will consider domestic technical concerns with RCC including freeze thaw susceptibility, general constructability, and quality control issues. 15 pp., 9 references.