| 摘要 |
PURPOSE:To provide a grouting method capable of maintaining the pH-value of the groundwater in the grouted ground within the vauge of the water quality standard (pH:5.8-8.6) even if the pH-value of a formulated grout is <=5, by formulating a non-alkaline silicic acid aqueous solution in a specific composition range. CONSTITUTION:The pH-value of the grout consisting of a non-alkaline silicic acid aqueous solution is adjusted to <=5 and the value of [H<+>]/[SiO2]<n> to ca. 1X10<-13> or less by admixing water glass with an acidic reactant to eliminate the alkaline component in the water glass {where, [SiO2] is molar concentration (mol/l) of the silicon dioxide in the water glass in the aqueous solution; n is molar ratio of the water glass; [H<+>] is molar concentration of the hydrogen ion in the solution}. Thus, flocculation of the silicic acid is effectively prevented. The grout, with low viscosity, shows outstanding performance because the whole amount of the silicic acid present in the water glass separates out completely over a sufficiently long period of the penetration into the ground, being gelled, thus effecting firm binding of the ground. |
