The use of DMA to characterize the aging of asphalt binders.

Details

• Creators:
  Daly, William H. ; Negulescu, Ioan I. ; Mohammad, Louay N. ; Chiparus, Ionela
• Corporate Creators:
  Louisiana Transportation Research Center
• Corporate Contributors:
  Louisiana. Dept. of Transportation and Development ; United States. Federal Highway Administration ; Louisiana State University (Baton Rouge, La.). Department of Civil and Environmental Engineering
• Subject/TRT Terms:
  • Binders
  • Dynamic tests
  • Field studies
  • Rheology
  • Mechanical analysis
  • Polymer Modified Asphalt Cement
  • Dry Aging
  • Wet Aging
  • Field Aging
  • FTIR
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• Publication/ Report Number:
  FHWA/LA.07/461
• Resource Type:
  Tech Report
• Geographical Coverage:
  Louisiana
• Edition:
  Final; Feb. 2004-Jan. 2007.
• Corporate Publisher:
  Louisiana Transportation Research Center
• Abstract:
  This report presents issues associated with long-term aging of polymer modified asphalt cements (PMACs) as ; reflected by dynamic mechanical analysis (DMA) data. In this study a standard SBS (styrene-butadiene-styrene block ; copolymer) polymer modified asphalt cement containing 3% copolymer (PMAC) meeting LADOTD specifications ; for PAC-40HG and PG 76-22M was selected and subjected to accelerated laboratory aging. Procedures were ; developed for simulation of long term aging of asphalt binders using multiple pressure aging vessel (PAV) operations ; in the absence and in the presence of water. Three, five and seven year old field aged asphalt samples originally of ; similar PMAC composition as that of PG 76-22 listed above were recovered from a wearing course mixture located on ; interstate I-55 near Granada, MS. All binders were characterized with respect to their composition and rheological ; properties. The extent of oxidation of both laboratory- and field-aged aged samples was estimated from Fourier ; transform infrared (FTIR) spectroscopy analysis and non-aqueous potentiometric titration data.. Changes in the ; molecular mass of the asphalt cement components were estimated from gel permeation chromatography (GPC) ; measurements. Aging determined a drastic reduction of molecular mass of SBS species and an increase in the content ; of large molecular species (LMS) asphalt components. Dynamic viscoelastic properties were determined using a high ; torque instrument. The asphalt architecture has been simulated with that of a gel. The cross-over temperature at ; which G” equals G’ at a frequency of 10rad/s as temperature increases was considered as the critical temperature, Tc, ; and chosen as a criterion to assess the advancement of hardening (aging). Oxidative aging in the presence of water ; promoted an increase in the carbonyl content of aged samples, primarily as acid groups, but the high humidity aging ; reduced the extent of asphalt hardening. Critical temperature of the field 3 year old I-55 paving sample correlated ; better with the laboratory wet 0.5xPAV aged PMAC sample, Tc of the field 5 year sample was intermediate between ; Tc of the dry 0.5xPAV and that of the dry 1.0xPAV laboratory aged PMAC samples and Tc of the field 7 year old ; sample correlated better with the laboratory dry 1.0xPAV aged PMAC sample. This type of correlation was used to ; determine if a binder extracted from the damaged LA 3234 Hwy road pavement was excessively aged after three years ; of service.
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• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/20284/dot_20284_DS1.pdf
• File Type:
  [PDF - 534.96 KB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:cf1290d084175fbfefe280e0904075ae3f821b13795c0ad0433dd6342de1bc131e0b7b2d2dea9fa5293b41eeb13c8cd2c3d07b5cc375a208e574cc0e77ed786a