A Screening Tool for Assessment of Moisture-Induced Damage of Asphalt Mixes Containing Rap Based on Molecular Dynamics Simulation

Details

• Creators:
  Peters, Andrew ; Wasiuddin, Nazimuddin M.
• Corporate Creators:
  Louisiana Tech University. Civil Engineering Program
• Corporate Contributors:
  The Southern Plains Transportation Center (SPTC) Region 6 University Transportation Center (UTC)
• Subject/TRT Terms:
  Adhesion Asphalt Mixtures Moisture Damage Reclaimed Asphalt Pavements Rejuvenators Simulation
• Publication/ Report Number:
  CY1-LTU-02
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Edition:
  Final Report 9-2023 to 1-2025
• Corporate Publisher:
  The Southern Plains Transportation Center (SPTC) Region 6 University Transportation Center (UTC)
• Abstract:
  Moisture-induced damage in asphalt pavements remains a significant challenge for road infrastructure durability. This study investigated the adhesive interactions between asphalt binder and aggregate surfaces, with particular focus on the effects of moisture and polyethylene (PE) modification. Using atomistic molecular dynamics simulations, we quantified the adhesion energy between a model SHRP AAA-1 asphalt binder and SiO2 aggregate surface under various moisture conditions. The simulation methodology was validated by achieving dry adhesion energies (46 mJ/m²) consistent with experimental measurements. Interestingly, low water concentrations (<0.5 waters per nm²) initially increased adhesion energy, possibly due to enhanced hydrogen bonding. The addition of PE (2.52 wt%) to the asphalt binder produced two significant effects: it reduced the dry binding energy to 33 mJ/m², likely due to PE's non-polar nature, but demonstrated a protective effect against water damage at higher moisture concentrations. While unmodified asphalt showed continuous degradation of adhesion with increasing moisture content, PE-modified binder maintained stable binding energies around 28-29 mJ/m² (greater than the 23 mJ/m2 for unmodified asphalt, which continued to decrease). This stabilization effect appears related to PE's hydrophobic nature, which helps repel water from the asphalt-aggregate interface. These findings suggest PE modification could improve moisture damage resistance in wet conditions, though further investigation of its effects on dry properties is needed.
• Format:
  PDF
• Funding:
  69A3552348306
• Collection(s):
  University Transportation Centers
• Main Document Checksum:
  urn:sha-512:3a62948975a992fa02e21b61575ecb3f13f68c39827cbc3500e8bb442c8495e7a2ee6ca0210abfeeb54f9b90e1117d7828dc18b6e53b97e71869d7fd19fdd259
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/88290/dot_88290_DS1.pdf
• File Type:
  [PDF - 6.30 MB ]