Evaluation of the effects of hot mix asphalt density on mixture fatigue performance, rutting performance and MEPDG distress predictions

The purpose of this study was to evaluate the effect of density on the fatigue cracking and rutting performance of hot mix asphalt mixtures. Two plant produced Superpave mixtures, 9.5 and 12.5 mm, were utilised to fabricate specimens to target density levels of 88, 91, 94 and 97% of the theoretical maximum specific gravity. The specimens were used to evaluate the mixture stiffness in the asphalt mixture performance test device, fatigue cracking characteristics utilising the beam fatigue test and the overlay test-based fatigue cracking analysis and rutting potential using the asphalt pavement analyser and the flow number test. Additionally, the mechanistic-empirical pavement design guide (MEPDG) distress prediction equations were used to predict the mixture performance as function of density. Overall, the testing analysis and MEPDG predictions indicated that higher density specimens yielded improved fatigue and rutting performance.