Evaluation of Low-Temperature Cracking (LTC) Performance Testing Methods to Assess Nebraska Asphalt Mixtures

Details

• Creators:
  Bastola, Nitish R. ; Teixeira, Jamilla E. S. L. ; Ho, Chun-Hsing
• Corporate Creators:
  University of Nebraska--Lincoln. Charles W. Durham School of Architectural Engineering and Construction ; University of Nebraska--Lincoln. Nebraska Transportation Center
• Corporate Contributors:
  Nebraska. Department of Transportation ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  • Mix design
  • Low temperature
  • Cracking
  • Recycled materials
  • Mixtures
  • Performance evaluations
  • Asphalt mixtures
  • Laboratory tests
  • Evaluation
  • Balanced mix design
  More +
• Publication/ Report Number:
  SPR-FY25(039)
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Nebraska
• Edition:
  Final Report
• Corporate Publisher:
  Nebraska. Department of Transportation
• Abstract:
  Current advancements in asphalt mixture design in the United States are increasingly shifting toward performance-based specifications, particularly through implementation of the Balanced Mix Design (BMD) framework. However, most existing BMD protocols primarily emphasize rutting and mid-temperature cracking resistance, often overlooking low-temperature cracking (LTC),which is a critical distress mode in cold-climate regions. This study aims to investigate LTC performance-based methodologies for the asphalt mix design to support the development of a Nebraska BMD framework. With that, selection of appropriate LTC performance tests that can be sensitive to Nebraska recycled mixture's variables was the main goal developed in this phase of study. To this end, well-established mixture-level LTC tests were sought, including Semi-Circular Bending (SCB) test, Indirect Tensile(IDT) Creep/Strength Test, and Bending Beam Rheometer (BBR) for mixtures, and performance parameters from different mixtures were compared. Dynamic modulus (DM) test was also conducted to verify potential differences in mixture's stiffness at sub-zero temperature. Additionally, commonly used binder level tests (DSR and BBR) and IDEAL-CT tests were performed to complete the binder and mixture performance characterization, respectively. Three Nebraska recycled mixtures subjected to short- and long-term aging protocols were selected in this initial phase of the study, being two SPR mixtures (SPR1 and SPR2) and one SLX. Binder-level results highlighted the limitations of binder testing in differentiating the LTC performance of the studied recycled mixtures. At the mixture level, lab-produced SPR mixtures exhibited different LTC performance trends. SCB fracture energy and IDT creep compliance were the only index parameters that consistently captured these differences. Plant-produced SPR and SLX mixtures confirmed the sensitivity of selected performance-based index parameters to differentiate the mixture's LTC resistance. Finally, these laboratory-derived indicators were compared against observed field thermal cracking performance to assess the predictive accuracy and applicability of the laboratory test methods at a field-production scale. Findings from this report must be extended for a broad range of mixtures and site locations.
• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/92841/dot_92841_DS1.pdf
• File Type:
  [PDF - 3.24 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:94119e8976afccc4dac0c6671bfa2ce7d389df3248c6ad841eaf327d7e71aaa7fcd3eb88955861f48ad3745573b7e908293348f0d68f8072b50b7a138635b084