| 摘要 |
PROBLEM TO BE SOLVED: To obtain a grout of which the homogel has a very long gelling time and which exhibits a gel strength practically enough by using, as effective components, an aq. active silicic acid soln. and an acidic reactant. SOLUTION: This grout is prepd. by adding at least one acidic reactant selected from phosphoric, sulfuric, hydrochloric, and citric acids, etc., to an aq. active silicic acid soln. to adjust the pH to lower than 2. If necessary, a sequestering agent (e.g. a polyphosphate), a metal corrosion preventive (e.g. N,N-dibutylthiourea), and a polymn. inhibitor (e.g. glycerin) are incorporated into the grout. The gelling time of the homogel is at least 5 days, and the unconfiend compression strength of solidified sand is 0.5 kg/cm<2> or higher. The aq. active silicic acid soln. is prepd. by removing alkali ions from a water- soluble silicate (e.g. sodium silicate) by an ion-exchange method, etc., has at least one silanol group capable of participating in condesation in an aq. soln. at a pH of 2-4, and has a mol.wt. of 1,000 or lower, an average particle size of 1-2 nm, and an SiO2 concn. of 12 wt.% or lower. |
