Using Polymer Modified Asphalt Emulsions in Surface Treatments A ...

2.9.4 Fillers
Airey et al (2002) present the findings of a laboratory investigation into the effects of
mixing SBS modifier with CRM to produce impact absorbing asphalt (IAA) surfaces (17).
The results of this study show that the polymeric viscoelastic characteristics of the SBS
are lost due to precipitation and phase-separation caused by the absorption of light
aromatics contained within the maltene fractions by the CRM particles. In properly
mixed SBS PMA which does not contain CRM, the SBS latex particles absorb these
light maltene fractions, which results in the swelling of the polymer phase, thereby
producing a continuous elastic network.
The availability of literature covering interactions between polymer modifiers and other
types of fillers was scant.
2.10 Surface Treatments, Distress, and Cost-Effectiveness
The selection of appropriate surface treatments and the decision on whether or not to
utilize polymer modifiers are dependent upon a number of factors, including:
• The effectiveness of a given treatment in rectifying a particular form of pavement
distress;
• The cost-effectiveness of a particular treatment relative to the benefits and cost
of other alternatives;
• The environmental conditions under which the treatment is to be applied;
• The functional classification and/or traffic loading conditions of the roadway to be
treated;
• The current condition of the underlying roadway, the type of pavement involved,
and its construction and maintenance history; and,
• The availability of appropriate materials and well-trained maintenance forces to
insure proper placement.
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