AbstractAsphalt pavement properties (strength, durability, bearing capacity, etc.) are considerably affected by environmental conditions. Because of this fact, regions with severe climates (high thermal gradients, abundant precipitation, presence of freeze-thaw cycles, solar radiation, etc.) have serious problems in maintaining the functional integrity of these infrastructures. Thus, it is necessary to develop new materials that could extend the service life of these pavements without increasing the construction costs. Accordingly, the present paper studies the improvement of the mechanical performance of high-modulus asphalt mixtures through the addition of acrylic fibers, for their use under severe environmental conditions. For this purpose, different tests were carried out thermal stress restrained specimen test, immersed wheel-tracking test, freeze-thaw sensitivity test, and UGR-FACT (University of Granada-Fatigue Asphalt Cracking Test) under variable conditions (simulating cold and hot scenarios). The results show that the use of acrylic fibers improves the mechanical behavior of high-modulus asphalt mixtures (at high and low temperatures, as well as under the presence of water and ice), and could thus be considered an interesting alternative for extending the service life of asphalt pavements in severe climates.