Green high viscosity toughness asphalt modifier, modified asphalt, bituminous concrete and preparation methods thereof

A green high viscosity toughness asphalt modifier, which comprises following raw material components by weight:

• 70-232 parts of waste rubber and plastic mixture;
• 4-10 parts of nano-clay material;
• and
• 15-50 parts of compatilizer, wherein:
• the waste rubber and plastic mixture consists of waste rubber and waste plastics with a mass ratio in a range of 1:(0.8-1.5);
• the waste rubber is waste rubber powder with a particle size in a range of 40 to 120 meshes, wherein a content of rubber hydrocarbon in the waste rubber is larger than 50%;
• the waste plastics are waste polyethylene particles or waste polypropylene particles with a particle size in a range of 10 to 15 meshes;
• the nano-clay material is at least one member selected from a group consisting of nano-organic montmorillonite, nano-rectorite, and nano-vermiculite;
• the asphalt modifier is prepared by secondary melt blending extrusion method, wherein the secondary melt blending extrusion method comprises steps of:
• (1) preparing masterbatch by a first melt blending extrusion, which comprises weighing the nano-clay material, the waste rubber and plastic mixture and the compatilizer in accordance with a weight ratio of 1:(2-4):(1-2), mixing evenly at high speed, extruding and granulating for obtaining the masterbatch;
• and
• (2) performing a second melt blending extrusion, which comprises mixing evenly the waste rubber and plastic mixture, the masterbatch obtained by the step (1) and the compatilizer with a weight ratio of (5-9):(1-5):(1-3) at high speed, extruding and granulating for obtaining the asphalt modifier.