Thermoplastic rubbers for the modification of bitumens: improved elastic recovery for high deformation resistance of asphalt mixes

Modification of bitumens with thermoplastic rubbers of the styrene-butadiene-styrene (SBS) type increases the deformation resistance of asphalt mixes markedly, even if the modification level is relatively low, e.g. 3 per cent. This phenomenon is closely related to the highly elastic nature of SBS-modified binders. The effect of these binders in asphalt mixes was studied in experiments in a Laboratory Test Track (LTT), which offers the closest simulation of asphalt performance in practice. Unlike static creep testing, dynamic creep proved to give a good correlation with the results obtained in the LTT. With the dynamic creep test, the mechanism of deformation upon loading could be studied in detail. It was shown that the elastic recovery upon deformation in the asphalt mix was significantly higher with the SBS-modified binders than with the neat bitumens. Elastic recovery of the binders can be demonstrated in a simple test using the ductilometer and thus the high efficiency of the SBS was confirmed. Moreover, after the Rolling Thin Film Oven Test (RTFOT) the highly elastic nature of these binders was maintained. Further, in comparison with their unmodified counterparts, the SBS-modified binders showed improved performance after RTFOT in terms of hardening. Ethylene/vinyl acetate (EVA) modified binders were also tested for elastic recovery before and after RTFOT and were found not only to be less effective than the SBS-modified binders but also to lose ductility and elastic recovery performance much more rapidly (A).

• Record URL:
  http://arrbknowledge.com
• Authors:
  • Valkering, C P
  • Vonk, W
• Conference:
  • Australian Road Research Board (ARRB) Conference, 15th, 1990, Darwin, Northern Territory
• Publication Date: 1990

Language

• English

Media Info

• Pagination: Jan-19
• Serial:
  • Volume: 15
  • Issue Number: 2

Subject/Index Terms

• TRT Terms: Bitumen; Bituminous binders; Bituminous pavements; Deformation; Materials tests; Mix design; Properties of materials; Thermoplastic materials
• ATRI Terms: Asphalt; Bitumen; Deformation; Material properties; Material testing; Mix design; Polymer modified binder; Thermoplastic
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 01431050
• Record Type: Publication
• Source Agency: ARRB
• Files: ATRI
• Created Date: Aug 24 2012 4:20PM