Characterization of thermal, high-temperature rheological and fatigue properties of asphalt mastic containing fly ash cenosphere

Abstract

This paper aims at evaluating the thermal, high-temperature rheological and fatigue properties of asphalt mastic, which was prepared using fly ash cenosphere (FAC) with a hollow sphere structure to replace equal volume of limestone mineral filler (LMF). A series of experiment were performed to investigate the physical, microscopic and chemical properties of the two fillers, as well as the thermal, high-temperature rheological and fatigue performances of asphalt mastics. The particle size distributions, surface characteristics, morphological information, chemical compositions and crystal structures of the fillers were first characterized. Based on the observed Fourier transform infrared spectrometry, it is found that FAC was physically blended with asphalt. The result of thermal conductivity test indicates that FAC reduced the thermal conductivity of asphalt mastic by 37.8%. Dynamic shear rheometer was used to perform a series of test, including temperature/frequency sweep test, steady shear viscosity test, multiple stress creep recovery test and linear amplitude sweep test, to evaluate the high-temperature rheological and fatigue properties of asphalt mastic. The results show that the addition of FAC generally had negative effects on both the high-temperature and fatigue properties of asphalt mastic. The study findings indicate that, although it is effective to prepare the low-thermal-conductive asphalt mixture using LMF, further studies are required to improve the interaction between asphalt and FAC, therefore, to mitigate the reduced high-temperature rheological and fatigue properties of asphalt mastic.