Polyurethane, modified asphalt and mixture material containing same and pavement structure

A method for preparing a polyurethane-modified asphalt, comprising:

• (a) adding a polymerization inhibitor, a catalyst, and an isocyanate component into a reactor;
• (b) adding a polyol to the reactor while stirring the resulted mixture at room temperature under nitrogen;
• (c) heating the mixture obtained from (b) to a temperature of 50-80° C., and holding the temperature to react for 0.5 to 6 hours to obtain a polyurethane prepolymer;
• and
• (d) continuously reacting the polyurethane prepolymer obtained from (c) in an asphalt or asphalt mixture material system under high temperature to produce the polyurethane-modified asphalt,
• wherein,
• the polymerization inhibitor comprises one or two selected from the group consisting of p-benzenesulfonate, benzoyl chloride, phosphoric acid, and dimethyl sulfate;
• the isocyanate component comprises one or two selected from the group consisting of liquefied MDI, TDI dimer, TDI trimer, TDI-TMP adduct, HDI dimer, HDI trimer, and IPDI trimer;
• and
• the polyol comprises one or more selected from the group consisting of castor oil, dehydrated castor oil, adipic acid-based polyester diol, polyolefin polyol, polyoxypropylene glycol, polyoxypropylene-oxyethylene copolyether triol, trimethylolpropane, vegetable oil polyol, and polytetrahydrofuran polyol.