Evaluation of mechanical properties and aging index of 10-year field aged asphalt materials

Abstract

Ten years’ field aged asphalt specimens have collected and being detailed studied. The aging index, viscoelastic behavior of aged binder recovered from the cored specimens, indirect tensile strength and residual fatigue life of the top layer and underneath layer were studied. Saturates, Aromatics, Resins and Asphaltenes (SARA) analysis and Fourier Transform Infrared Analysis (FTIR), viscoelastic analysis, Indirect Tensile (IDT) resilient modulus and fatigue test were performed.Both SARA, FTIR and viscoelastic analysis indicates that traffic loading does have positive degradation influence on asphalt binder. FTIR shows that traffic loading has limited influence on the chemic changes of SO compounds, while has positive contribution on degrading the CC bonds and hence promotes the oxidize aging. Although surface layer can protect underneath asphalt layer from aging, 10-year field aging would introduce significant deterioration onto the underneath layer. The effective aging depth can go as deep as to the second layer. Fatigue tests illustrate that 10-year service has resulted in very weak asphalt pavement surface. Its fatigue life is very sensitive to traffic loading.