Hydrogel-cement composite material

A hydrogel-cement composite grouting material under flowing water, wherein, comprising following raw materials in parts by weight:

• 99.5-99.98 parts of a cement, 0.02-0.5 parts of a strengthening hydrogel, and 80-100 parts of a water;
• and
• the strengthening hydrogel is prepared by adopting a method comprising following steps (1)-(5):
• in the step (1), uniformly mixing a polyvinyl alcohol solution and a sodium alginate solution, and stirring in an ice-water bath;
• a concentration of the polyvinyl alcohol solution and the concentration of the sodium alginate solution is 2 wt. %, and a mass ratio of the polyvinyl alcohol solution to the sodium alginate solution is (8-10):
• 9;
• and
• in the step (2), adding a dispersion liquid of nano-ettringite whiskers to a mixture obtained from the step (1), and uniformly stirring;
• the mass ratio of the nano-ettringite whiskers to the polyvinyl alcohol solution in the dispersion liquid of nano-ettringite whiskers is (2-2.5):
• 9;
• and
• in the step (3), adding a calcium chloride solution to a mixture solution obtained from the step (2), and carrying out a cross-linking reaction;
• a time of the cross-linking reaction is 2.5-3.5 h;
• and
• in the step (4), crushing and drying a cross-linking product obtained from the cross-linking reaction to obtain solid particles;
• and
• in the step (5), soaking the solid particles in the mixture solution of a glutaraldehyde solution and a hydrochloric acid solution to obtain the strengthening hydrogel after soaking.