Mix design and properties of RCC at Mujib dam ― high and low cementitious content

摘要

Detailed mix design studies with site specifc materials for Mujib Dam using various cement contents, pozzolan contents, and moisture contents indicated that the original intended design with pozzolan and a high cementitious content should be adjusted to a low cement content with no pozzolan. The Jordanian pozzolan was simply not effective in RCC made with the local aggregates, and the high cementitious content mixes were not efficient. The change resulted in much lower cementitious materials costs, it allowed relaxed thermal controls, it allowed larger joint spacings, and it eliminated the need for washing aggregates by allowing a relaxed gradation with more aggregate fines, and it extended the construction season. With a cement content of 85 kg/m~3 and no pozzolan the RCC is achieving 1 year strengths of 12.9 MPa compression and an estimated 1.1 MPa direct tensile (1.75 MPa split tensile). The density was very good at 2530 kg/m~3. These properties exceed design requirements.