Backcalculated Dynamic Modulus Master Curve From the Time Histories of Falling Weight Deflectometer Surface Deflections

Details

• Creators:
  Notani, Mohammad Ali ; Cho, Seonghwan ; Haddock, John E.
• Corporate Creators:
  Purdue University. Joint Transportation Research Program
• Corporate Contributors:
  Indiana Department of Transportation ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  Asphalt Pavements Back-calculation Cost Effectiveness Dynamic Modulus Of Elasticity Falling Weight Deflectometers Master Curve Mechanistic Design Nondestructive Tests Rehabilitation Structural Stability (Mechanics)
• Publication/ Report Number:
  FHWA/IN/JTRP-2025/18
• DOI:
  https://doi.org/10.5703/1288284317898
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Edition:
  Final Report
• Corporate Publisher:
  Purdue University. Joint Transportation Research Program
• Abstract:
  Accurate structural evaluation of flexible pavements is important for cost-efficient maintenance and rehabilitation (M&R) strategies. Traditional back-calculation methods based on Falling Weight Deflectometer (FWD) data assume elastic behavior, overlooking the viscoelastic nature of asphalt materials and subsequently leading to inaccuracies. This study introduces a mechanistic-based back-calculation technique to estimate the dynamic modulus (E*) master curve directly from FWD time-history data. By integrating layered elastic theory with viscoelastic principles, the proposed method first determines the relaxation modulus, E(t), using Differential-Time Fourier Transform (DTFT) analysis. This time-domain response is then converted into the frequency domain to construct the E* master curve. Validation against laboratory-measured dynamic modulus values from field-cored specimens demonstrates that the proposed technique generates highly accurate E* master curves for all asphalt layers. Moreover, the findings highlighted the importance of accurate pavement structural information, such as layer thickness and Poisson’s ratio, for achieving reliable E* master curve.
• Format:
  PDF
• Funding:
  SPR-4619
• Collection(s):
  FAA William J. Hughes Technical Center for Advanced Aerospace
• Main Document Checksum:
  urn:sha-512:eab42d3b857df964bea3ca5ecfd26a016df1f1e6b9350a8cbdf8d6b57450edc4e7dc7706ca85b4b4bf3b88af0ef8eaba3af451f886f25ab4ff6cee410cb76e91
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/92427/dot_92427_DS1.pdf
• File Type:
  [PDF - 10.69 MB ]