Experimental evaluation and recyclability potential of asphalt concrete mixtures with polyacrylonitrile fibers

Recently, the use of fibers has become an attractive option to be implemented as reinforcement in Asphalt Concrete (AC) mixtures. Nonetheless, few studies have been carried out to evaluate the recyclability potential of AC mixtures incorporating fibers. In this study, the reinforcing effect of polyacrylonitrile (PAN) fibers in AC mixtures is investigated. Air voids, Marshall stability, indirect tensile strength (ITS), moisture sensitivity, compactability, rutting, stiffness, and fatigue were the tests taken into consideration. In addition, bituminous mixtures manufactured with higher quantities of artificial reclaimed asphalt pavement containing PAN fibers (PANRAP) were evaluated experimentally. The results indicate that PAN fibers significantly increased the resistance to permanent deformation of the AC mixture. Improvements in ITS, moisture sensitivity and stiffness keeping the same fatigue life were also observed. In addition, a suitable performance was found in mixtures incorporating PANRAP in relation to control mix and remarkable increases in ITS, rutting, and stiffness were noted. The present investigation provides technical evidence of recycling AC mixtures with fibers up to 50% without the presence of rejuvenators.