Abstract: Formula studies on low-pH value cement for geological disposal were conducted with ordinary portland cement and silica fume employed. The key parameters thereof are also determined. Verification tests of cement and silica fume system were carried out. The results show that, for such a low-pH value cement, the major factor which effecting initial, final setting time and 28 d compressive strength is water/dry materials, while that for90 d pH is SiO₂ content and Ca/Si, i.e., the content of Ca(OH)₂ in products.

Key words: Geological disposal, Low-pH cement, Formulation