High-viscosity, high-elasticity, and anti-aging composite modified asphalt and a preparation method thereof

A high-viscosity, high-elasticity, and anti-aging composite modified asphalt, characterized by, according to parts by mass, comprising the following components:

• 100 parts of a matrix asphalt, 12 parts of a thermoplastic styrene-butadiene rubber, 7 parts of a tackifier, 1 part of a plasticizer, 3 parts of a compatibilizer, 0.25 parts of a stabilizer, and 0.05 parts of an anti-aging agent,
• the tackifier is a compound of a resin and a polyisoprene derivative, and the resin is a rosin modified resin, the structural formula of the polyisoprene derivative is:
• the mass ratio of the resin to the polyisoprene derivative is 2:1,
• the thermoplastic styrene-butadiene rubber has a linear structure, and has a block ratio S/B of 30/70,
• the plasticizer is dioctyl phthalate, the compatibilizer is an extract oil from furfural refining, the stabilizer is sulfur, and the anti-aging agent is 9,9-dimethylacridine,
• the high-viscosity, high-elasticity, and anti-aging composite modified asphalt is prepared by the following method:
• step 1:
• melting a matrix asphalt and maintaining the temperature, adding weighed plasticizer, compatibilizer and anti-aging agent to the molten asphalt, and dispersing evenly;
• step 2:
• adding a thermoplastic styrene-butadiene rubber to the asphalt obtained in the step 1, swelling, then heating up, and shearing at a high speed to completely dissolve the thermoplastic elastomer in the asphalt;
• the specific method of the step 2 comprises:
• adding the weighed thermoplastic styrene-butadiene rubber to the asphalt obtained in step 1, stirring, swelling for 10 min, then heating the asphalt to 180±5° C., and shearing at a high speed of 4500-5500 r/min for 20-40 min to completely dissolve the thermoplastic elastomer in the asphalt;
• step 3:
• adding a tackifier to the asphalt obtained in the step 2, adding a stabilizer after high-speed shearing, and then shearing for stable crosslinking;
• and
• step 4:
• developing the asphalt obtained in the step 3, and regularly removing gas, so as to obtain a high-viscosity, high-elasticity, high-performance, and anti-aging composite modified asphalt;
• the specific step of the step 4 comprises:
• after shearing is completed, transferring a modified asphalt sample into an oven at 170-180° C. for development for 45 minutes, and stirring the asphalt sample every 10-15 minutes to discharge the air mixed in the asphalt, so as to obtain a high-viscosity, high-elasticity, high-performance, and anti-aging composite modified asphalt;
• The high-viscosity, high performance, aging resistant composite modified asphalt has a dynamic viscosity of 253248 at 60° C., a needle penetration at 25° C. of 51.2, a ductility at 25° C. of 42.5 cm, a softening point of 96.4° C., a storage stability of 1.5° C. of 48 h, a residual needle penetration at 25° C. of 79% after RTFOT, and a residual ductility at 5° C. of 34 cm.