Rheological properties of fiber reinforced asphalt binders

Abstract

<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="metricconverter"> Cellulose fiber, polyester fiber and mineral fiber are employed as additives to prepare fiber reinforced asphalt binders in this paper, with a concentration ranging from 0 to 1.0 %. Viscosity test, dynamic shear test and creep test are conducted to investigate the rheological characteristics of fiber reinforced asphalt binders. Experimental results indicate that the viscosity of fiber reinforced asphalt binders is increased by the addition of fibers, especially when the fiber concentration is up to 0.5 % by mass of asphalt binder. Complex shear modulus of fiber reinforced asphalt binders are increased, which indicate that the stiffness of asphalt binders can be enhanced by the use of fiber additives. The elastic part of viscoelastic behaviours of asphalt binders are enhanced by the addition of fibers, which result in the reduction of the phase angle. The master curves of complex shear modulus of fiber reinforced asphalt binders are determined based on nonlinear least square regression according to the time-temperature superposition theory at a control temperature (20°C). It is implied that the reinforcing effects of fibers are more significant at lower frequencies. The development of creep strain curves for asphalt binders varied remarkably by the addition of fibers. The total strain during loading period and the permanent strain are reduced greatly when fibers are added, which revealed that the resistance to permanent deformation can be significantly improved for asphalt binders containing fibers. </smarttagtype>