Use of the Asphalt Pavement Analyzer and Repeated Simple Shear Test at Constant Height to Augment Superpave Volumetric Mix Design

摘要

As accelerated pavement testing (APT) devices emerge as possible candidates for a supplemental performance test, questions related to the ability to assess resistance of hot mix asphalt to permanent deformation under full-scale trafficking remain. Toward addressing this question, performance data under full-scale trafficking collected for several replacement sections at WesTrack were compared with test results for mixtures fabricated in the laboratory using WesTrack materials and tested at a critical temperature for permanent deformation. The asphalt pavement analyzer (APA) and repeated simple shear test at constant height (RSST-CH) were validated as useful APT tools by comparing measured field performance and laboratory predicted performance of laboratory mixed-laboratory compacted specimens at field (in-place) air void and asphalt contents. Test results from the APA and RSST-CH showed good agreement with downward rut depths measured under full-scale trafficking. Based on a simple statistical analysis, the APA test can be used to assess adequate rutting performance. Rutting performance was also assessed by determining the expected number of design equivalent single axial loads (ESALs) for each section from relationships between permanent shear strain in the RSST-CH and ESALs in the field. Both APT devices demonstrated the ability to differentiate between mixtures with good and poor rutting performance.