This study focuses on the development of sustainable road materials by utilizing waste flakes generated from the PET plastic recycling process. The plastic flakes were used to partially replace asphalt cement in asphalt concrete mixtures at replacement ratios of 5–20% by weight.The experimental results indicated that the most suitable replacement ratio for asphalt cement is 0–10% by weight. Regarding material properties, the asphalt concrete mixed with plastic flakes exhibited increased density