Rheological behaviors of asphalt binders reinforced by various fibers

Abstract

Incorporating different fibers contributes to improving the properties of asphalt materials. In this study, chopped basalt fibers (CBFs), flocculent basalt fibers (FBFs), lignin fibers (LFs), and polyester fibers (PFs) were mixed into SBS modified asphalt at four contents (1%, 2%, 3%, and 4% by weight of SBS modified asphalt) to prepare fiber-reinforced asphalt (FRA) samples for dynamic shear rheology (DSR) tests, including temperature sweep, multiple stress creep recovery (MSCR), and linear amplitude sweep (LAS) tests. The microscopic characteristics of the incorporated fibers and those of the remnants of FRAs after screening out the fibers were also determined using scanning electron microscopy (SEM) and attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). The results demonstrated that the rheological behavior of FRA varied significantly with the type of fiber incorporated. Generally, the deformation recovery ability and anti-fatigue ability of SBS modified asphalt were improved by adding different fibers. With an increase in the fiber content, fiber network structures were gradually formed in the bundle fibers, including CBFs- and PFs-reinforced asphalt, resulting in an increase in the viscosity and high-temperature stability of FRA. Comparatively, flocculent fibers such as LFs and FBFs presented better improvements in terms of the elasticity, deformation recovery, and fatigue life (Nf) of FRA. The approximate characteristic peaks and values indicate that no chemical reactions were found between the fibers and the SBS modified asphalt. Property analysis revealed that the recommended content was 2%, 3%, 4%, and 4% for CBFs, PFs, LFs, and FBFs, respectively.