Method of paving a roadway using hydrogel modified subgrade

A method of paving a roadway using hydrogel modified subgrade, comprising:

• Step 1:
• cleaning a surface of a ground to be paved and compacted;
• Step 2:
• preparing the hydrogel modified subgrade, wherein the hydrogel modified subgrade comprises (by weight percentage, Wt. %):
• weather-resistant hydrogel 0.3%-1%, surfactant 0.2%-0.5%, and filling materials required for subgrade construction, and the weather-resistant hydrogel comprises ultrafine bentonite 20%-25%, sodium hydroxide solution 0.02%-0.08%, acrylic acid solution 0.2%-0.4%, initiator 0.2%-0.4%, N, N′ methylene-bis-acrylamide 0.2%-0.4%, 2-hydroxyethyl methacrylate 5%-10%;
• wherein, a preparation method of the hydrogel modified subgrade, comprises:
• Step 2.1:
• preparing an ultrafine bentonite aqueous solution, and stirring the ultrafine bentonite aqueous solution into a micro-paste dispersion state at a reinforced high-speed stir for 10-20 min, to obtain an ultrafine bentonite material;
• Step 2.2:
• titrating the sodium hydroxide solution into the acrylic acid solution to prepare an acrylic acid solution with a certain neutralization degree;
• Step 2.3:
• putting the acrylic acid solution obtained from step 2.2 in a four-mouth beaker, adding the ultrafine bentonite material and the N, N′ methylene-bis-acrylamide to the acrylic acid solution in sequence under a condition of nitrogen protection, stirring thoroughly and then carrying out an ultrasonic dispersion for 20-30 min to obtain a mixed solution;
• Step 2.4:
• adding potassium persulfate and the 2-hydroxyethyl methacrylate to the mixed solution of the step 2.3 and stirring thoroughly to obtain a solution, which is subjected to a rapid polymerization reaction under a certain constant-temperature water bath condition to obtain a gel mixture, and then drying, crushing and grinding the gel mixture to obtain a modified water-absorbing resin;
• Step 2.5:
• preparing the initiator and the surfactant in sequence;
• and
• Step 2.6:
• stirring and mixing the modified water-absorbing resin, the initiator, the surfactant, and the filling material required for subgrade construction to prepare and obtain the hydrogel modified subgrade;
• Step 3:
• paving a layer of the hydrogel modified subgrade on the surface of the ground to be paved to form a first-layer hydrogel modified subgrade by mechanically leveling and compacting;
• Step 4:
• paving and mechanically leveling and compacting a plain soil subgrade on a surface of the first-layer hydrogel modified subgrade;
• Step 5:
• paving another layer of the hydrogel modified subgrade on a surface of the plain soil subgrade to form a second-layer hydrogel modified subgrade;
• and
• Step 6:
• paving a pavement structure on a surface of the second-layer hydrogel modified subgrade.