Using DSR and FTIR to Evaluate Asphalt Binder Extracted and Recovered from Asphalt Mixtures

The asphalt content and aggregate gradation are critical factors related to the performance of asphalt mixtures. The solvent extraction is a traditional method which use chemical solvent to extract asphalt binder from the asphalt mixtures. However, there are some concerns on solvent extraction, for examples, fine aggregates are hard to completely separate from solvent during the filtration procedure, and therefore it is very challenging to fully evaporate solvent from asphalt binder. There is no commonly accepted method to qualitatively evaluate the residue contents of solvent in recovered asphalt binders. The remaining solvent in asphalt binders have great influence on the performance of recovered asphalt binders. The objectives of this research study are to investigate the influence of solvent in asphalt binder and further propose a method to determine the presence of solvent. The FTIR test was used to analyze the functional group of both trichloroethylene (TCE) and asphalt binder with TCE to quantitatively determine the existence of solvent. DSR tests were employed to evaluate the complex shear modulus and phase angle of recovered asphalt binders and estimated the actual performance of binders without TCE. From the testing results, it is concluded functional groups of TCE can be used as indicators to check for the existence of TCE in extracted asphalt. For PG 58-28, the peak area around wavenumber of 837 cm-¹ and 928 cm-¹ have a relationship to the TCE percentage in asphalt binder. The peak area around wavenumber of 837 cm-¹ and 928 cm-¹ are the same for PG 58-34 with different TCE content. More tests with different PG grades may needed. For both PG 58-28 and PG 58-34, |G*| decreased gradually with the increase of TCE content. And the value of phase angle increased with the addition of TCE. A mathematical function could be built to establish a relationship between TCE content and |G*|. We can estimate the TCE amount by calculating the FTIR spectrum area, and back calculate the actual complex shear modulus of asphalt with TCE.


  • English

Media Info

  • Media Type: Web
  • Features: References;
  • Monograph Title: Congress on Technical Advancement 2017: Construction and Forensic Engineering

Subject/Index Terms

Filing Info

  • Accession Number: 01692465
  • Record Type: Publication
  • ISBN: 9780784481035
  • Files: TRIS, ASCE
  • Created Date: Feb 8 2019 5:00PM