Oil gel for asphalt modification and rejuvenation

A recycled asphalt pavement composition comprising:

• asphalt rejuvenator, virgin asphalt, and RAP and/or RAS, wherein said asphalt rejuvenator comprises bio-based oil or a bio-based oil blend capable of supporting at least 40 wt. % styrene butadiene block copolymer and an antioxidant system, said styrene butadiene block copolymer comprises:
• (i) a diblock copolymer comprising one block of a monoalkenyl arene and one block of a conjugated diene having a peak molecular weight from 30,000 to 78,000 and a vinyl content from 35 to 80 mol percent based on the number of repeat monomer units in the conjugated diene block, and (ii) a block copolymer comprising at least two blocks of monoalkenyl arene and at least one block of conjugated diene, the block copolymer selected from the group consisting of linear triblock copolymers having a peak molecular weight that is 1.5 to 3.0 times the peak molecular weight of the diblock copolymer, multiarm coupled block copolymers having a peak molecular weight that is 1.5 to 9.0 times the peak molecular weight of the diblock copolymer, and mixtures thereof, wherein each block copolymer has a vinyl content from 35 to 80 mol percent based on the number of repeat monomer units in the conjugated diene block, wherein the melt index for the styrene butadiene block copolymer is from about 15 g/10 min. to about 50 g/10 min. as determined by ASTM D-1238, condition G (200° C., under 5 kg load) and wherein the ratio of (i) to (ii) in the styrene butadiene block copolymer is greater than 1:1.

A method of making a recycled asphalt pavement composition, comprising:

• preparing an asphalt rejuvenator by uniformly blending 60-35 wt. % bio-based oil or a bio-based oil blend, 40-65 wt. % styrene butadiene block copolymer, wherein said bio-based oil or bio-based oil blend has a flash point >230° C. and can support 40 wt. % styrene butadiene block copolymer, and an antioxidant system, said asphalt rejuvenator at 180° C. has a maximum viscosity of <2000 cps when measured at 6.8/seconds shear rate, and said styrene butadiene block copolymer comprises:
• i) a diblock copolymer comprising one block of a monoalkenyl arene and one block of a conjugated diene having a peak molecular weight from 30,000 to 78,000 and a vinyl content from 35 to 80 mol percent based on the number of repeat monomer units in the conjugated diene block, and
• (ii) a block copolymer comprising at least two blocks of monoalkenyl arene and at least one block of conjugated diene, the block copolymer selected from the group consisting of linear triblock copolymers having a peak molecular weight that is 1.5 to 3.0 times the peak molecular weight of the diblock copolymer, multiarm coupled block copolymers having a peak molecular weight that is 1.5 to 9.0 times the peak molecular weight of the diblock copolymer, and mixtures thereof, wherein each block copolymer has a vinyl content from 35 to 80 mol percent based on the number of repeat monomer units in the conjugated diene block, wherein the melt index for the styrene butadiene block copolymer is from about 15 g/10 min. to about 50 g/10 min. as determined by ASTM D-1238, condition G (200° C., under 5 kg load) and wherein the ratio of (i) to (ii) in the styrene butadiene block copolymer is greater than 1:1;
• and
• blending said asphalt rejuvenator with hot virgin asphalt and RAP and/or RAS.