Extensive shear testing for Saluda dam roller compacted concrete

Stability of the new Saluda RCC dam (safety berm) depends on adequate friction between RCC lift joints after separation and initial sliding during the design earthquake. Extensive tests were carried out on large full scale blocks of various RCC mixes made under full scale production conditions to determine initial friction and residual friction after sliding under various confining loads. Joints were tested with various lift joint maturities, bedding, cement contents, and other conditions. Although some variables had slight influence on test results, for all practical purposes the residual friction angle was acceptable and mostly independent of all variables.