Development of an index to evaluate the cracking potential of asphalt mixtures using the semi-circular bending test

•A review of the Illinois Flexibility Index Test (I-FIT) is presented.•An alternative cracking parameter called Cracking Resistance Index (CRI) is developed.•CRI is less variable and easier to calculate as compared to the Flexibility Index (FI) parameter.•CRI shows greater distinction between different asphalt mixtures with different properties.•CRI is sensitive to binder PG, recycled materials content, and the presence of recycling agents. This study introduced a cracking parameter, called the Cracking Resistance Index (CRI), derived from the load-displacement response obtained during a semi-circular bending test, and compared it to the recently developed Flexibility Index (FI). Laboratory test results indicated that both FI and CRI are sensitive to binder Performance Grade, recycled materials content, and recycling agent dosage. The results indicated the dependency of the two indices on specimen thickness and air voids content. A reasonable correlation between FI and CRI was verified. As compared to the FI, the proposed CRI provided better distinction between different asphalt mixtures, less variability, and easier calculation.