AbstractGuayule resin was investigated through mixture to assess its role in the field performance. For performance comparisons, conventional asphalt, neat guayule, asphalt–rubber–guayule, and guayule–rubber binders were implied. Field-simulated lab mixtures were made to investigate the major distresses. Modified Lottman, rut, semicircular bending, and disk-shaped compact tension tests were used to assess stripping, rutting, fatigue, and thermal cracking resistances. Stripping and rutting susceptibilities were also assessed by Hamburg wheel-tracking test. The outcomes disclosed that when the modified Lottman test was used, guayule containing a 7% air content was more susceptible to stripping than that containing a 3.5% air content, resulting in tensile strength ratios of 40% and 71%, respectively. All investigated mixtures did not reach out the stripping inflection point under the Hamburg wheel-tracking criteria. Asphalt offered the worst Hamburg rut depth, which was 3.2 mm after 20,000 passes. Guayule-based mixtures perfectly resisted rutting as proven by the rut test. Guayule offered the worst rut depth of 6.3 mm, indicating a great rutting resistance. The guayule-based mixture had a high fracture toughness at intermediate temperatures. Guayule and guayule–rubber mixtures offered a critical strain energy release rate of 0.65–0.69  kJ/m2 compared to 0.46  kJ/m2 for asphalt. They, however, tended to possess low thermal fracture resistance (less than the threshold fracture energy, 400  J/m2). Conversely, a blend of 62.5% asphalt, 12.5% rubber, and 25% guayule offered 591  J/m2 at its performance grade low temperature (−16°C) and 409  J/m2 at −22°C compared to 429  J/m2 for asphalt at the later temperature, which represented the performance-grade low temperature of asphalt.

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