Mechanical properties investigation of high-fluidity impermeable and anti-cracking concrete in high roller-compacted concrete dams

To solve the seepage problem of roller-compacted concrete (RCC) gravity dams, grout-enriched vibrated RCC (GEVR) and immersion vibrated RCC (IVRCC) have been widely used as the primary impervious materials. However, the vibration process required for these materials severely impedes the rapid construction of RCC dams. To reduce the construction disturbance on RCC impervious structures, we propose a new type of self-compacting concrete (SCC), namely, high-fluidity impermeable and anti-cracking concrete (HIAC). HIAC is formed by partially replacing cement with an equal amount of expansion agent and by adjusting the mixture proportions through trial testing. The comprehensive performance of HIAC was studied using tests on its compressive strength, elastic modulus, permeability and, in particular, the mechanical properties of the interface between HIAC and RCC, using a large roller-compacted specimen. The results indicated that HIAC meets the basic requirements of hydraulic concrete. The compressive strength reached 1.52 times the design strength, and the permeability grade of the HIAC was greater than W34. In addition, the interfacial properties between HIAC and RCC were favorable. Relative to RCC, higher splitting strength was measured at the interface of HIAC and RCC. Therefore, using HIAC as the impervious material instead of GEVR facilitates simpler, faster and higher-quality construction. These advantages signify that HIAC is a promising material in hydraulic engineering.