| 摘要 |
One embodiment provides a process for preparing an asphalt-coated crumb rubber composition that meets the specification set forth in ASTM D80-02 or deviations thereof which may be established by the specifying agency from time to time. The process generally comprises obtaining asphalt of different penetration grades, combining the asphalt of each grade with preselected chemicals to form separate premixed components, blending the premixed components together under predetermined conditions to form, upon curing, an asphalt-coated crumb rubber composition that meets certain physical requirements for asphalt-rubber binder (ARB), such as those set forth in ASTM D8-02. Advantageously, the resulting asphalt-coated crumb rubber composition not only meets the physical requirements of ARB used in road paving but also has improved dispersion of the rubber, such as dispersion of the rubber in an oil-in-water emulsion of an asphalt. |
| 主权项 |
1. An emulsion of an asphalt-rubber binder comprising:
a mixture of a first asphalt emulsion and swelled asphalt-coated crumb rubber particles, wherein the first asphalt emulsion comprises a first asphalt mixed with water and a surfactant, wherein the first asphalt has a pen value of about 0 dmm to about 50 dmm and wherein the surfactant is selected from the group consisting of amines, ammonium salts, amidoamines, imidazolines, imidoamincs, imines, amides, imadazoles, imidazolencs, and combinations thereof, wherein the swelled asphalt-coated crumb rubber particles comprise crumb rubber particles having a diameter of from 75-650 microns and being coated and swelled by a second asphalt at a temperature of 325° F. to about 375° F., wherein the second asphalt has a pen value 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; wherein the swelled asphalt-coated crumb rubber particles are substantially homogenized into first asphalt droplets of the first asphalt emulsion, 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 a total weight of all non-volatile components of the smooth and uniform emulsion, and wherein the smooth and uniform emulsion is stable at a pH below about 7. |
