| 摘要 |
PURPOSE: Provided is a high strength urethane liquid composition for solidifying the weak ground used in the polyurethane injection technique of NATM (new Austrian tunneling method) which can maintain strength to be constant owing to a small effect of water even if the liquid composition is absorbed in the underground water during injection process. CONSTITUTION: The urethane liquid composition comprises a liquid A which comprises 65-85 wt% of a polyol containing a polyol having at least two hydroxyl groups and 10-15 wt% of an oil having a hydroxyl group capable of urethane reaction; and a liquid B which comprises an isocyanate compound containing an isocyanate group, in a ratio of 1:1 to 1:1.1 by weight. Preferably the polyol having at least two hydroxyl groups is at least one selected from a di- or more valent alcohol polymer such as a polyoxyalkylene diol, a polyoxyalkylene triol, glycerin, sorbitol, etc.; the oil having a hydroxyl group capable of urethane reaction is at least one selected from a camellia oil, an olive oil and a castor oil; and the isocyanate compound is a prepolymer obtained by reacting diphenylmethane diisocyanate and a polyol. Preferably the liquid A comprises further at least one catalyst selected from an organometallic catalyst and a tertiary amine-based catalyst. |
