Abstract: Underground oil storage in rock caverns became one of the widely-used oil storage facilities owing to its good performance. But due to its characteristic of permeability without leakage, drainage and oil-water separation are required for the operation in the late period. Excessive permeability would increase the running cost and bring about negative effects on its long-term security. On the basis of surrounding rock’s good condition, the permeability resistance of shotcrete increased by adding S95 ground granulated blast-furnace slag without reducing shotcrete’s basic properties. The long-term durability of shotcrete is improved, and the operation cost of underground oil storage caverns is reduced. The influence of slag ratio on setting time and working performance of shotcrete is analyzed so as to optimize the mix proportion of basic concrete. The compressive strength, rebound ratio, bond strength and anti-permeability performance of the slag-mixed shotcrete are researched. Results showed that: 1) slag delayed the setting time of shotcrete slightly, but had no adverse effect on shotcrete’s rebound ratio and bond strength 2) slag improved concrete’s workability, further reduced shotcrete’s water-cement ratio, and enhanced the performance of shotcrete in later stage 3) shotcrete mixed with slag displayed good anti-permeability performance for early self-compacting properties and secondary hydration.

Key words: shotcrete, underground oil storage in rock caverns, ground granulated blast furnace slag, durability