Abstract Indonesia is currently importing oil bitumen to meet its asphalt needs. One of the best solutions is to utilize Asbuton, which is not affected by the global oil price increases. One of the engineering issues being developed is improving the rheological properties of bitumen by adding Asbuton. The aim of this study is to provide an overview of the improvement in rheological properties due to the addition of pure Asbuton to a Pen 80/100 asphalt mixture. Basic rheological property tests were conducted with variations of 0%, 2%, 6%, 10%, 30%, 50%, 70%, 90%, 94%, 98%, and 100% pure Asbuton content, and mechanistic rheological property tests were carried out using a Dynamic Shear Rheometer with variations of 0%, 2%, 6%, 10%, and 30% pure Asbuton content. The basic rheological properties obtained from this study showed a decrease in penetration value, an increase in softening point, and a decrease in ductility and elastic recovery. Meanwhile, the mechanistic rheological properties of the bitumen mixture also showed an increase in Performance Grade (PG) in the original condition, RTFO condition, and PAV condition. Based on the Mastercurve, the addition of pure Asbuton caused the bitumen to be more sensitive to changes in temperature and loading frequency. In the Black Diagram review, there was a decrease in the phase angle (δ) value, indicating that the bitumen became more durable. Keywords: Asbuton, Asphalt Pen 80/100, Black Diagram, Complex Shear Modulus, Master Curve, phase angle Abstrak Indonesia saat ini masih melakukan impor aspal minyak untuk memenuhi kebutuhan aspalnya, maka salah satu cara yang terbaik adalah memanfaatkan Asbuton yang nilai harganya tidak terpengaruh dengan kenaikan harga minyak dunia. Salah satu isu kerekayasaan yang berkembang adalah meningkatkan sifat reologi dari bitumen dengan menambahkan Asbuton. Tujuan penelitian ini yaitu untuk mendapatkan gambaran dari perbaikan sifat reologi akibat penambahan Asbuton murni pada campuran Aspal Pen 80/100 dilakukan pengujian sifat reologi dasar dengan variasi: 0%, 2%, 6%, 10%, 30%, 50%, 70%, 90%, 94%, 98%, dan 100% kadar Asbuton murni dan pengujian sifat reologi mekanistik dengan alat Dynamic Shear Rheometer dengan variasi: 0%, 2%, 6%, 10%, dan 30% kadar Asbuton murni. Sifat reologi dasar yang diperoleh dari penelitian ini terjadinya penurunan nilai penetrasi, peningkatan titik melembek serta penurunan daktilitas dan elastic recovery. Sedangkan dari sifat reologi mekanistik campuran bitumen juga mengalami peningkatan Performance Grade (PG) pada kondisi original, kondisi RTFO, dan pada kondisi PAV. Berdasarkan Mastercurve dengan penambahan Asbuton murni menyebabkan bitumen lebih sensitif terhadap perubahan temperatur dan frekuensi pembebanan. Sedangkan dalam tinjauan Black Diagram terjadinya penurunan nilai phase angle (δ) sehingga bitumen semakin durable. Kata-kata Kunci: Asbuton, Aspal Pen 80/100, Black Diagram, Complex Shear Modulus, Master Curve, phase angle