Patent ID: 8808445
Filing Date: 2014-08-19
Classification: C08L,C09D,C09J

Abstract:
1. A method for preparing an emulsion of an asphalt-rubber binder comprising: mixing a first asphalt with water and a first surfactant to form a first asphalt emulsion, wherein the first asphalt has a pen value in the range of about 0 dmm to about 50 dmm, wherein the first asphalt emulsion has a temperature of from about 190° F. to about 210° F. after mixing, and wherein the first surfactant is selected from the group consisting of amines, ammonium salts, amidoamines, imidazolines, imidoamines, imines, amides, imidazoles, imidazolenes, and combination thereof; mixing crumb rubber particles having a diameter of from 75-650 microns with a second asphalt at a temperature of 325° F. to about 375° F., whereby the crumb rubber particles are coated with the second asphalt, wherein the crumb rubber particles swell in a presence of the second asphalt, wherein the second asphalt has a pen value in the range of about 90 dmm to about 200 dmm, and wherein the crumb rubber particles and the second asphalt yield a mixture having a viscosity in a range of from about 900 cps to about 1500 cps; and mixing the first asphalt emulsion with the swelled asphalt-coated crumb rubber particles, whereby the swelled asphalt-coated crumb rubber particles are substantially homogenized into asphalt droplets of the first asphalt emulsion, thereby forming a smooth and uniform emulsion of an asphalt-rubber binder, wherein the smooth and uniform emulsion of the asphalt-rubber binder comprises about 15% to about 30% crumb rubber based upon the total weight of all non-volatile components of the smooth and uniform emulsion.