This activity seeks to provide tools for agencies to be able to take more active measures against flexible pavement deterioration rather than passively observing cracking distress before taking action. Both full-scale mixture tests and reduced scale mixture tests are to be applied from the current research knowledge. The type of full-scale tests that will be applied are those that can be used in mix design and/or acceptance tests. The full-scale tests balance practicality with more engineering significance of cracking and damage because they are to be able to be performed in the asphalt mix performance tester (formerly simple performance tester) but go beyond |E*| stiffness. One test is viscoelastic continuum damage push-pull that provides continuum crack initiation context, and the second test is a fracture mechanics crack propagation type test. These are in harmony with Federal Highway Administration research stakeholders. The small-scale tests focus on viscoelastic properties generated from the ubiquitous Bending Beam Rheometer. This thrust is geared more towards surrogates of the full-scale mix tests and maximize practicality by allowing field (throughout a pavement's life cycle) sampling of thinner layers. The mixture itself is tested without the cumbersome and expensive solvent extraction routines. Further, the small-scale test allows much greater flexibility and resolution in laboratory accelerated aging to be explored in three different candidates: long-term oven aging, pressure aging vessel, and Weatherometer. The greater resolution in simulated aging provides more data points to emulate the lifetime of a pavement.
The key project objective is to develop laboratory test protocols for binders and mixtures with recommended criteria to quantify remaining crack resistant life.