Development of Criteria for Durability of Modified Asphalt - Final Report Author(s): Tia, M.; Ruth, B.E., Huang, S.C., Chiu, C.T. and Richardson, D. Origin: Florida Date: November, 1994 Categories: Performance Key Words: Asphalt durability, TFOT, RTFOT, California tilt oven, gisonite, carbon black, GTR, SBR, SEBS, EVA, pressure aging vessel, Schweyer rheometer Summary: 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.