VISCOELASTIC, FATIGUE DAMAGE, AND PERMANENT DEFORMATION CHARACTERIZATION OF HIGH RAP BITUMINOUS MIXTURES USING FINE AGGREGATE MATRIX (FAM)

Performance characteristics of bituminous mixtures play the most influential role in designing flexible pavement. These asphaltic mixtures can be considered as heterogeneous mixtures which composed of two primary components: fine aggregate matrix (FAM) phase and aggregate phase. The FAM phase acts as a critical phase in evaluating the performance characteristics including viscoelastic, fatigue damage, and permanent deformation characteristics of entire asphalt mixtures. This study evaluates the viscoelastic, fatigue damage and permanent deformation characteristics of bituminous mixtures containing 65% reclaimed asphalt pavement (RAP) by performing oscillatory torsional shear tests of cylindrical bars of FAM using a dynamic mechanical analyzer. Moreover, this study investigates a linkage between performance characteristics of asphalt concrete (AC) mixture and its corresponding FAM phase. To meet the objectives of this study, laboratory tests were performed for several FAM mixtures with 65% reclaimed asphalt pavement and different types of rejuvenators and one warm mix asphalt (WMA) additive. Test results were then analyzed using viscoelastic theories and fatigue prediction models based on continuum damage mechanics. Furthermore, obtained laboratory test results were compared with corresponding test results of asphalt concrete mixtures. The test results indicated that rejuvenators change properties and performance behavior related to fatigue damage and permanent deformation of high reclaimed asphalt pavement mixtures. In addition, test results of FAM phase were generally linked well with asphalt concrete mixture test results, and they vividly depicted that FAM phase could provide core information to predict the behavior of the asphalt concrete mixture. Advisor: Yong-Rak Ki