Asphalt Rubber Technology Information Center
Development of Criteria for Durability of Modified Asphalt - Final Report
Tia, M.; Ruth, B.E., Huang, S.C., Chiu, C.T. and Richardson, D.  
November, 1994  
Key Words:
Asphalt durability, TFOT, RTFOT, California tilt oven, gisonite, carbon black, GTR, SBR, SEBS, EVA, pressure aging
vessel, Schweyer rheometer  
A laboratory investigation was conducted to evaluate the effects of a few promising modifiers on the long-term aging
characteristics of typical asphalt cements and asphalt concrete mixtures used in Florida.  The seven types of modifiers
evaluated in this study include (1) gilsonite, (2) carbon black, (3) fine ground tire rubber (GTR-80), (4) coarse ground tire
rubber (GTR-40), (5) stryrene-butadiene rubber (SBR), (6) ethylene vinyl acetate (EVA), (7)
styrene-ehtylene-butylene-styrene.  These modifiers were blended with an AC-30, AC-20 and AC-5 to produce various
modified asphalts for this study.    The results of the study indicate that the addition of modifiers generally reduces the
rate of aging of the asphalts.  AC-30 asphalt appears to be too hard and AC-5 asphalt appears to be too soft for use in
modified asphalts in Florida.
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