SUPERPAVE SUPPORT AND PERFORMANCE MODELS MANAGEMENT: EVALUATION OF THE SHRP PERFORMANCE MODELS SYSTEM

A principal result of the Strategic Highway Research Program (SHRP) was a set of pavement performance models for predicting low temperature thermal cracking, fatigue cracking, and permanent deformation in asphalt pavements under environmental and traffic loadings. The Federal Highway Administration, as part of its Superpave implementation plan, awarded a contract to the University of Maryland and a team of subcontractors to provide a comprehensive and unbiased evaluation of the original SHRP pavement performance models. The principal conclusions from this evaluation are: (a) the SHRP Superpave system provides an excellent framework for future modifications and enhancements to the models; (b) the existing non-load related thermal fracture model predicts field behavior reasonably well, although some minor modifications and enhancements to the model are necessary; (c) the performance prediction models for load related fatigue fracture and permanent deformation perform poorly, and substantial corrections and enhancements to these models are imperative if they are to be sufficiently reliable for acceptance and use by industry; (d) although some of the problems in the load related distress models are the consequence of technical and other constraints during the original SHRP research effort, many are the direct result of problems in the asphalt material characterization models and associated test procedures; and (e) the necessary corrections, modifications, and enhancements to the models will mandate new field calibration and validation. Detailed evaluation findings supporting these conclusions are presented in the paper. Future plans for the enhancement and implementation of the Superpave performance models are also briefly described.