The present invention discloses methods of making improved rubber modified
asphalt cement compositions, and compositions made by the method, where
the compositions are useful in paving, roofing, coating and other sealing
applications. In one aspect, the method comprises combining asphalt, RVPR
(or a blended mixture of asphalt and RVPR) and at least one dodecyl or
tridecylbenzene sulfonic acid (SA), which can be linear (LAS) or branched
(BAS), in the presence of moderate heat. After heating the resultant RMAC
mixture exhibits at least one of the following: (1) an increase in
softening point, (2) an increase in hardness, or (3) improved recovery
from deformation. In another aspect, the invention teaches addition of at
least one SA to previously manufactured RMAC to accomplish at least one
of the following: (1) an increase in softening point, (2) an increase in
hardness, or (3) improved recovery from deformation. For paving
compositions, the resultant RMAC mixtures made by the methods of the
invention are mixed with an appropriate grade of aggregate composition,
and other paving materials as desired.