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Conventional index-based testing of asphalt mixtures cannot accurately capture local deformation in a sample, limiting the usage of standard test measurements. The non-contact-based measurements proved effective to capture local deformation fields. This study aimed to capture the fatigue and thermal cracking behaviour of fiber-reinforced asphalt mixture (FRAM) by utilising digital image correlation (DIC). One binder (PG76-22), a diabase aggregate and three fibers (polyolefin/ aramid fibers (PFA) at 0.05% dosage and Sasobit-coated aramid fibers at 0.01% and 0.02% dosage) were used to prepare a total of four mixtures (one control and three FRAM). All these mixtures were produced at a local batch plant following manufacturer-recommended mixing methods. DIC analysis was performed for three-point bending beam (3PB) and disk shape compact tension (DCT) tests at intermediate temperature (25°C) and low temperatures of −12°C and −18°C. Based on index values from DCT and 3PB, the thermal and fatigue cracking performance enhancement was not significant. However, DIC analysis showed that, regardless of testing temperature, the crack propagated in a random pattern for FRAM, whereas the crack followed a relatively straight path for the control mix. Finally, based on DIC strain contours, FRAM mixtures exhibit distributed strain over a larger area compared to the control mix. [ABSTRACT FROM AUTHOR]

This study was conducted to assess the impact of combined polyolefin/aramid fibers (PFA) and pure synthetic aramid fibers (AF) reinforcement on mix design properties and laboratory performance. The study also investigated the shift in laboratory performance (rutting to cracking and vice versa) with the addition of both type of fibers. One aggregate (diabase stone), one binder type (PG58–28), and two types of aramid fibers (combined polyolefin/ aramid fibers and synthetic aramid fibers), added at 0.05% dosage by mix weight, were used to produce two fiber-reinforced asphalt mixtures (FRAM). Additionally, a control mix was also produced without any reinforcement. Mix design for control and FRAM was performed and Optimum Binder Content (OBC) was determined. The laboratory rutting and cracking performance of the mixtures was assessed using Asphalt Pavement Analyzer (APA), Flow Number (FN) and Indirect Tension Asphalt Cracking Test (IDEAL-CT). Durability and stiffness of these mixtures were also determined by performing Cantabro loss and Dynamic Modulus (DCM) tests. According to the mix design results, PFA reinforced mix showed an offset bulk and theoretical maximum specific gravity. However, both control and FRAM mixtures showed the same OBC (5.7%). Both type of fibers improved the durability of mix. With addition of PFA and AF fibers into the asphalt mix, the performance trend shifted from rut resistant mix to crack resistant mix, respectively. Furthermore, addition of PFA fibers into the asphalt mix increased the toughness and AF fibers make the asphalt mix ductile. • Laboratory performance of pure synthetic fibers and polyolefin/ aramid (PFA) fibers were evaluated. • Fibers were mixed in the Hobart mixer at 0.05% dosage by mix weight. • At such a low dosage, air voids are consistent. • These fiber types have improved the durability of asphalt concrete. • Synthetic aramid fibers improved the cracking performance and PFA improved the rutting resistance. [ABSTRACT FROM AUTHOR]