FATIGUE RESPONSE OF ASPHALT MIXTURES TESTED BY THE FEDERAL HIGHWAY ADMINISTRATION'S ACCELERATED LOADING FACILITY

Fatigue testing of asphalt mixtures was conducted using the beam fatigue device proposed by SHRP researchers. The results from laboratory prepared specimens were compared to results from field sections tested under controlled conditions by the Federal Highway Administration's Accelerated Loading Facility (ALF). The results indicate that a direct comparison of fatigue life between laboratory and field material is not possible since laboratory properties do not account for pavement structure. However, relative comparisons between asphalt type and layer thickness are possible and can be used to aid in the selection of materials and structure of a pavement. Using the data from the ALF and the laboratory, a preliminary evaluation of the binder parameter G*sin was done. The conclusion is that G*sin? is only applicable to pavement sections under relatively high tensile strains that mimic the strain-controlled conditions under which the parameter was derived.