Sustainable recycling technology for rejuvenating aged bitumen by hydrothermal decomposition

2023 Fiscal Year Final Research Report

• Project/Area Number: 19H02219
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 22010:Civil engineering material, execution and construction management-related
• Research Institution: Nihon University
• Principal Investigator: KANOU Yousuke 日本大学, 生産工学部, 教授 (50451315)
• Co-Investigator(Kenkyū-buntansha): 新田 弘之 国立研究開発法人土木研究所, 土木研究所(つくば中央研究所), 研究グループ長 (00355869) ; 秋葉 正一 日本大学, 生産工学部, 教授 (10267031)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 舗装材料 / リサイクル / アスファルト / 亜臨界水 / 水熱分解 / 持続的利用

Outline of Final Research Achievements

Through this research, we have worked on developing an asphalt rejuvenation technology using water (high-temperature, high-pressure water). As a result, we have found that when subcritical water near the critical point is used as a solvent, the asphalt becomes lighter as the reaction temperature and reaction time increase, and that reaction conditions of 350°C and 15 minutes are appropriate for reusing asphalt as a paving material. Furthermore, we have confirmed that asphalt that has been repeatedly recycled and has aged and deteriorated can be rejuvenated to a quality comparable to that of new asphalt by hydrothermal decomposition under the same conditions.

Free Research Field

土木工学

Academic Significance and Societal Importance of the Research Achievements

本技術は、道路舗装の維持修繕工事に伴い年間約2,000万トン発生する再生資材の持続的利用ならびに高品質化を目指したものであり、「水と油」の関係性に着目した新たなアプローチによる研究要素を含む。よって、本研究の成果は、水熱分解における反応条件が重質油の化学的・物理的性状に及ぼす影響を明らかにするとともに、高温高圧水を応用した新たなマテリアルリサイクルの可能性、社会インフラの維持・更新に伴う資源の持続的利用、環境負荷低減の可能性を広げる一助となることを期待する。