Evaluation of Semicircular Bending Test for Assessing Cracking Potential of Superpave Mixtures with High Reclaimed Asphalt Pavement Content

Premature cracking of Superpave pavements with higher proportion of Reclaimed Asphalt Pavement (RAP) materials is a major concern in Kansas. This research was done to assess the suitability of the Semi-Circular Bending (SCB) test for evaluating cracking potential of Superpave mixture with high RAP content. Three sources of RAP and three RAP proportions (20%, 30% and 40%) were used in this study. Static and repetitive load SCB tests were conducted on samples compacted with the Superpave gyratory compactor. The peak load to cracking, time to crack initiation, and maximum strain in these tests were measured. The Analysis of Variance (ANOVA) was used to find out statistically whether cracking resistance of a certain mix varies with the RAP proportion used in the mix. ANOVA results showed that higher amount of RAP decreases cracking resistance of HMA mixes. RAP source is also an influencing factor in determining cracking resistance of HMA mixes with RAP.