Effect of additives on performance of asphalt mixtures

The new mechanistic-empirical design guide introduced by the American Association of State Highway and Transportation Officials relies heavilyon performance testing results of asphalt concrete mixtures (asphalts) as input to predict pavement service life. In addition, the National Cooperative Highway Research Program, USA 9-19 project introduced the concept of simple performance testing to complement the Superpavemixture design. There is a significant debate about whether these procedures are sensitive to and/or suitable for asphalts withmodified bitumen binders (binders). This study was initiated to evaluate the sensitivity of the new asphalt performance tests to modified binders. Two aggregates, three types ofmodified binder and one conventional unmodified binderwere used to conduct a parametric study. The testing included asphalt rutting, asphalt dynamic modulus, and indirect tensile test before and after water conditioning. Modifiers include one anti-stripping additive and two polymeric additives. The results show that the tests are very effective inmeasuring modifier effects. In general, the anti-stripping additive shows no apparent effect on rutting resistance and on dynamic modulus at high temperatures, but it shows some effect on modulus at low temperatures. Polymeric additives show apparent effects on all aspects of rutting resistance and dynamicmodulus. Also, polymeric additives increase the resistance of asphalts to moisture damagemore than the increase shown by the anti-stripping additive for the two aggregate types used (granite and limestone). The results are very encouraging in the sense that newtests can be effectively used to study the performancemodifications offered by various additives used in practice. (A)

  • Availability:
  • Authors:
    • CHO, D W
    • BAHIA, H
  • Publication Date: 2006-8


  • English

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  • Accession Number: 01050735
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, ATRI
  • Created Date: Jun 5 2007 12:01AM