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 Dry Aging Dynamic Mechanical Analysis Dynamic Tests Field Aging Field Studies FTIR GPC Mechanical Analysis Polymer Modified Asphalt Cement Rheology Wet Aging

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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.
  
  
• Format:
  PDF
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:90b2d2ddf402cc0600e7342f62fd4f18c88578ebe24e5f0a7b4b23b36b1c2804
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/20284/dot_20284_DS1.pdf
• File Type:
  [PDF - 534.96 KB ]