Laboratory assessment of porous asphalt mixtures reinforced with synthetic fibers

Abstract

Porous asphalt (PA) mixtures have become a new alternative in the development of new road pavement surface layers given their multiple advantages such as surface runoff improvement, the decrease of the urban heat island effect, the reduction of road traffic noise and the minimization of the spray and aquaplaning effect leading to a safer driving. However, the durability of these mixtures is not as good as for dense graded mixtures. This research studies the effectiveness of adding a blend of polyolefin/aramid fibers and homopolymer polyacrylonitrile fibers in PA mixtures in terms of functionality and mechanical performance. Furthermore, changes in the filler content are assessed. The experimental testing plan includes air voids characterization, permeability, moisture sensitivity and particle loss in dry and wet conditions. Improvements in the mechanical performance can be observed in dry conditions. Finally, the fracture energy, postcracking energy and toughness are also analyzed. The results show that the addition of fibers brings ductility to the PA mixture improving toughness while maintaining functionality since the air void content remains over 20%.