<p>We examined a process for obtaining a polymer composite material derived from petrochemical industry wastes and by-products in order to modify substandard commercial bitumen to improve its physical and mechanical characteristics. The resulting polymer composite consisting of pulverized polyethylene terephthalate, thermally unstable high-density polyethylene, and biodegradable polycaprolactone is considered as a replacement for traditional expensive thermoplastics such as styrene-butadiene, which was used for comparison. In laboratory studies, we found the main indices of the initial bitumen sample, bitumen with a plasticizing additive, and plasticized solutions of each polymer. The process of obtaining these polymer composites and their effect on bitumen binders are described. Samples of asphalt concrete mixtures were obtained. Feasibility was demonstrated for recycling of these nonstandard polymers to obtain a new material to improve the properties of road bitumen as well as a derived high-quality hot asphalt concrete mixture.</p>