This paper investigated the rheological performance of the combination of ethylene methyl acrylate and glycidyl methacrylate—EMA-GMA (reactive polymer)—and high-density polyethylene (HDPE) associated with polyphosphoric acid (PPA116%) in the modification of an asphalt binder (PG 64-XX). Tests such as performance grade (PG), multiple stress creep and recovery (MSCR), linear amplitude sweep (LAS), and master curve vary the EMA-GMA and PPA116% contents to obtain an ideal composition to provide a high-performance asphalt binder and thus compare with an unmodified asphalt binder and a styrene-butadiene-styrene (SBS) modified asphalt binder. The results showed that the asphalt binder stiffness improved as the EMA-GMA and PPA116% content increased. The PG temperature increased with the addition of PPA116% content in the asphalt binder samples, being most significant with the use of 1.8% of EMA-GMA. The addition of the combined polymers decreased the susceptibility to rut and improved the elastic recovery of the asphalt binder PG 64-XX, but only the samples with 1.8% EMA-GMA showed higher elastic recovery than the SBS-modified binder. PPA116% provided benefits in damage resistance at all strain levels; however, more was observed in samples subject to minor strains. The incorporation of 1.8% EMA-GMA, 0.3% HDPE, and 0.5% PPA116% was the one that presented the most improvements, without presenting gelation, in the performance of the asphalt binder in relation to stiffness and elasticity with increasing temperature. Thus, the use of these polymers in this composition can be a good alternative to regions with high temperatures, such as the northeast region of Brazil.