ABSTRACT
Transverse joint-grouting was necessary for conventional concrete arch dam. In the same way, repeated joint-grouting was also indispensable for high RCC arch dam that would undergo a slowly cooling process in a long time. This paper summarized the latest study on the repeated joint-grouting in RCC arch dam, and described the layout of a new type of repeated-grouting pipeline system, the details of the rubber sleeve valve served as grout outlet and the grouting experiments on large-scale concrete models. Grouting pressure, the maximum spreading radius of grout and the water pressure needed to wash the repeated-grouting pipeline were estimated according to hydromechanics theory. The use of the new repeated-grouting pipeline system in two RCC arch dams in China was also introduced.
