Investigating the possibility of constructing low cost roller compacted concrete dam

This research was set with the objective of investigating the possibility of constructing Roller Compacted-Concrete Dam, RCCD, using local material to reduce its cost. Trial laboratory concrete mixtures were conducted to define RCCD proportions in stage-I. Twelve mixtures with fly ash, FA, of cement replacement percentages (0%, 50%, and 60%) designed with water/cementitious- materials ratio, w/cm of 1.0 and 0.9. Cm-content of 1.50 kN/m³ and 1.20 kN/m³ was also examined. In stage-II, RCCD scale model was constructed based on the laboratory results. Descriptions of RCCD construction stages, dam monitoring system instrumentations and temperature measurements analysis were conducted. Results clarified how FA interacts with Portland cement and showed its effect on concrete properties especially strength development ratio. FA long-term reaction refines the pore concrete structure to reduce water ingress and control its seepage. FA reduces the thermal stresses by reducing the concrete hydration heat and reduces temperature-related cracking due to low early young’s modulus and finally leads to durability improvement that minimizes the dam construction cost. Results indicated that RCCD could be effectively implemented with site local Egyptian materials. However, more further field measurements and a RCCD prototype are required to be examined analytically and verified with in situ data to evaluate that technique.