Experimental study demonstrates that fiber reinforcement improves fracture resistance in porous asphalt exposed to chemical runoff, indicating enhanced pavement durability.
Key Points
To evaluate the intermediate-temperature fracture performance of limestone- and granite-based porous asphalt mixtures reinforced with basalt and polypropylene fibers following oxidative aging and chemical runoff immersion across various pH levels.
Fabricated porous asphalt mixtures using 60/70 penetration bitumen, two aggregate mineralogies (limestone and granite), and reinforcement with basalt fiber (BF) or polypropylene fiber (PPF).
Subjected samples to sequential conditioning: AASHTO R30 short- and long-term aging followed by vacuum saturation and 5-day immersion in solutions ranging from pH 5 to 9.
Evaluated cracking behavior via semicircular bending (SCB) tests, quantifying peak load, ultimate displacement, fracture energy, toughness index, balanced cracking index, and dissipated energy ratio.
BF consistently provided superior peak load-bearing capacity, while PPF achieved greater deformation capacity and fracture energy, increasing ultimate displacement by 36–77% in limestone and 36–75% in granite mixtures.
Fiber reinforcement increased overall fracture energy and crack tolerance by up to approximately 70% under favorable conditions compared to unreinforced mixtures.
Degradation was aggregate-dependent, with pH 9 causing the most severe damage in limestone mixtures and pH 5 causing greater deterioration in granite mixtures, while limestone generally showed higher overall stability.