Assessing Cracking Test Methods to Improve the Performance of ADOT Asphalt Mixes

Temperature and precipitation vary widely across Arizona, presenting a challenge in designing asphalt mixes for pavements that resist both cracking and rutting. A balanced approach to asphalt mixtures that considers both cracking and rutting resistance is important to minimize maintenance costs and extend the life of the pavement. ADOT currently uses both the Marshall and Superpave methods to design asphalt mixtures. The ADOT Materials Laboratory (Lab) obtained an apparatus for conducting the Ideal Cracking Test (IDEAL-CT) and has been investigating its use in evaluating asphalt cracking resistance, but has not applied other testing methods for this purpose. To potentially refine its mix designs and improve resistance to cracking and rutting, the Lab needs valid, reliable methods to test and predict performance. Assessment results would inform the Lab in choosing an appropriate cracking test method that would predict the cracking resistance of ADOT mixes. This project will focus on assessing test methods for the cracking resistance, but to achieve a balanced mix design, rutting will still need to be investigated so that mix designs that reduce cracking do not in the end increase rutting.