Patent ID: 7446139
Filing Date: 2008-11-04
Classification: C08K,C08L,C09D,E01C

Abstract:
1. A method for making a modified asphalt binder composition, comprising the steps of: a. providing neat asphalt in an appropriate vessel; b. heating the neat asphalt to a temperature of between about 120° C. and about 200° C.; c. adding to the neat asphalt a first modifying ingredient selected from the group consisting of at least one acid, at least one synthetic polymer and crumb rubber; d. mixing the asphalt and the first modifying ingredient with one of a high shear mixer or a low shear mixer for a period of between about 5 minutes and about 10 hours e. adding to the modified asphalt binder a second modifying ingredient selected from the group consisting of at least one acid, at least one synthetic polymer and crumb rubber, wherein the second modifying ingredient is a different type of ingredient than the first modifying ingredient; f. mixing the second modifying ingredient and the modified asphalt binder in one of a high shear mixer or a low shear mixer for a period of between about 5 minutes and about 10 hours g. adding to the modified asphalt binder a third modifying ingredient selected from the group consisting of at least one acid, at least one synthetic polymer and crumb rubber, wherein the third modifying ingredient is a different type of ingredient than the first modifying ingredient and the second modifying ingredient; and h. agitating the third modifying ingredient and the modified binder material in one of a low shear mixer or a high shear mixer for a period of between about 5 minutes and about 48 hours.