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Effects of Film Thickness, Wavelength, and Carbon Black on Photodegradation of Asphalt
| Title: | Effects of Film Thickness, Wavelength, and Carbon Black on Photodegradation of Asphalt |
| Other Titles: | アスファルトの光による劣化に及ぼす膜厚，波長ならびにカーボンブラック添加の影響 |
| Authors: | Yamaguchi, Katsuyuki1 Browse this author | | Sasaki, Iwao2 Browse this author →KAKEN DB | | Nishizaki, Itaru3 Browse this author | | Meiarashi, Seishi4 Browse this author | | Moriyoshi, Akihiro5 Browse this author →KAKEN DB |
| Authors(alt): | 山口, 勝之1 | | 佐々木, 厳2 | | 西崎, 到3 | | 明嵐, 政司4 | | 森吉, 昭博5 |
| Keywords: | Asphalt | | Photodegradation | | Ultraviolet irradiation | | Film thickness | | Wavelength | | Carbon black |
| Issue Date: | 2005 |
| Publisher: | Japan Petroleum Institute |
| Journal Title: | Journal of the Japan Petroleum Institute |
| Volume: | 48 |
| Issue: | 3 |
| Start Page: | 150 |
| End Page: | 155 |
| Publisher DOI: | 10.1627/jpi.48.150 |
| Abstract: | Focusing on sunlight that has severe effects on the degradation of asphalt pavement during service, this study examined the relationships between the film thickness of asphalt and the states of photodegradation. The results confirmed that thinner films had a higher modulus of elasticity, lower viscosity, and increased production of carbonyl groups, which is an indicator of oxidative degradation. The degree of degradation rapidly increased especially at thicknesses below 200 μm. The wavelength dependence of spectral photodegradation was also examined. Visual observations and the carbonyl index confirmed that ultraviolet irradiation in the range of 300 to 400 nm caused severe photodegradation of asphalt. Carbon black blocked light near the surface of the asphalt layer, where the damage caused by light is most severe. Addition of carbon black helps to prevent photodegradation by ultraviolet irradiation in the wavelength range of 300 to 400 nm. | | アスファルト舗装の供用中の劣化現象に影響の大きい光に注目し，この劣化におけるアスファルト単体の膜厚の影響を調査した。その結果，膜厚が薄くなるにつれて，特に200 μm以下の領域で，弾性率の増大や粘性の喪失，また酸化劣化を示すカルボニル基生成の増大など，劣化の程度が急激に著しくなることが確認された。また，分光劣化試験による波長依存性を調査した結果，外観変化やカルボニル指数の挙動より，アスファルトの光による劣化には波長範囲300～400 nmの紫外線の影響が大きいことを明らかにした。さらに，遮光性フィラーとして知られるカーボンブラックは，光による劣化の著しいアスファルト層の表面付近で機能し，波長300～400 nmの紫外線による劣化を抑える効果のあることが見出された。 |
| Type: | article |
| URI: | http://hdl.handle.net/2115/40070 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 森吉 昭博
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