Development of a Cyclic Semi-Circular Bend Test to Evaluate Asphalt Mixture Crack Propagation Properties at Intermediate Temperature

Details

• Creators:
  Mohammad, Louay N. ; Ma, Ye
• Corporate Creators:
  Louisiana State University. Department of Civil and Environmental Engineering
• Corporate Contributors:
  Louisiana. Department of Transportation and Development ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  Asphalt Concrete Asphalt Mixtures Bend Tests Cracking Of Asphalt Concrete Pavements Fatigue Cracking Image Analysis Service Life Temperature
• Publication/ Report Number:
  FHWA/LA.25/710
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Edition:
  Final Report 01/2021–06/2024
• Corporate Publisher:
  Louisiana. Department of Transportation and Development
• Abstract:
  The Semi-Circular Bend (SCB) test has traditionally been conducted in a monotonic loading and displacement-controlled mode at intermediate temperatures to assess the fatigue crack resistance of asphalt mixtures. However, fatigue damage is essentially the deterioration of material integrity as a result of repeated loading. The monotonic loading of the SCB does not accurately represent the repetitive nature of traffic loads. This may have limitations on the mechanism of fatigue cracking in asphalt mixtures. This study aims to develop a cyclic SCB test protocol to characterize the fatigue cracking of asphalt mixtures. A secondary goal is to apply the Paris’ Law coefficients obtained from the proposed cyclic SCB test in the pavement fatigue model for predicting pavement fatigue life. Digital Image Correlation (DIC) system configurations were set up for deformation and crack propagation measurements of mixture samples during cyclic SCB testing. Two indicators, including the number of cycles to failure and Paris’ Law coefficients, were used to characterize the fatigue cracking resistance of asphalt mixtures. The testing parameters of the cyclic SCB test, including notch depth and load frequency, were optimized, and a sensitivity analysis was designed and conducted for the proposed cyclic SCB test protocol using three asphalt mixtures with differing levels of cracking performance. To address the limitations of previous approaches that relied on indirect estimation and manual labeling during the analysis process, an innovative method was developed to directly measure the crack length during the cyclic SCB test. Additionally, the results of the Paris’ Law coefficients determined from the cyclic SCB test were utilized to predict the fatigue life of asphalt pavement.
• Format:
  PDF
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:53e208f7257ede0d5aec4cbfc9bee9dfbb058943be60e49d31b8d8490b7e4d6adbf18a41ee08b0af6dcfbfc7bfa46f963a099ec9aa0df07ee8f60bdeca1f3b59
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/85500/dot_85500_DS1.pdf
• File Type:
  [PDF - 4.72 MB ]