Experimental investigation on the performance of asphalt binders reinforced with basalt fibers

The laboratory performance of the asphalt binder reinforced with basalt fibers was compared with a control asphalt binder with no fibers in this study. The dosages of basalt fibers adopted for the study were 0.5%, 1.0%, 1.5%, 2.0% and 2.5% by weight of the asphalt binder. Scanning electron microscopy was used to study the microstructure of the basalt fibers and the fiber–asphalt binder interaction at different magnification levels. The rheological and creep recovery properties were investigated in this study using dynamic shear rheometer, while the conventional tests on binder, viz., penetration and softening, were also conducted. The scanning images indicate that the basalt fibers are smooth surfaced and round shaped that will not absorb any asphalt binder. Uniform distribution of fibers was observed indicating an efficient mixing methodology adopted. The penetration values were found to be decreased with the increase in fiber dosage, while the softening results were increased indicating thick binder which offers excellent resistance to deformation at higher temperatures. The rheological properties such as G*, phase angle (δ), G*/Sinδ, non-recoverable creep compliance (J_nr) and percent of recovery (R%) suggest that the basalt-modified asphalt binders provide a better opportunity to improve the rutting resistance, particularly at high temperatures. Also, it was observed that improvement in the performance of the binders is significant only up to a fiber dosage of 1% and the optimum dosage of basalt fibers can be fixed as 1% by the weight of asphalt binder.