Long-term performance of Roller Compacted Concrete at Upper Stillwater dam, Utah, USA

Upper Stillwater dam, completed in 1987, was the first large roller compacted concrete (RCC)

dam constructed using “high paste” mixture proportioning methods including 70 percent pozzolan by mass of cementitious materials and a more workable mixture with a Vebe consistency of 15 seconds. Long-term strength properties were investigated 14 years after construction with particular emphasis on direct tensile and shear strength of bonded lift lines. The results of this program demonstrate that the more workable RCC mixes are easily compacted and well bonded without the need for bonding mortars or bedding concrete between lift lines.