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A.N. Koyun, J Büchner, H. Grothe, M. Wistuba:
"Field aged and laboratory aged polymer-modified asphalt binder -investigation with fluorescence spectroscopy";
Vortrag: 9th EATA Conference, Wien (eingeladen); 07.06.2021 - 09.06.2021; in: "9th EATA Conference", 9th EATA Conference, 9th EATA Conference (2021), S. 20.

Field aged and laboratory aged polymer-modified asphalt binder -investigation with fluorescence spectroscopy
Koyun, A.*; Büchner, J.**; Wistuba, M.**; Grothe, H.*
*Institute of Materials Chemistry, TU Wien, Getreidemarkt 9/BC, A - 1060 Vienna, Austria **Braunschweig Pavement Engineering Centre (ISBS), Technische Universität Braunschweig, Beethovenstraße 51b, D - 38106 Braunschweig, Germany
Numerous factors affect the lifespan of asphalt roads, such as the climate, traffic and whether or not the owner performs routine maintenance. Ageing is caused by mechanical stress (steric or physical hardening), through rain water including oxidizing agents, thermal oxidation, solar radiation and reactive oxygen species (ROS) in the atmosphere. While mechanical stress also plays a crucial part in this study we are focusing on the oxidants from the atmosphere. Standardized binder tests such as rolling thin film oven test (RTFOT) and pressure ageing vessel (PAV) address mechanical and thermal oxidation, while UV radiation and ROS are neglected. The interaction of ozone and UV light with volatile organic compounds (VOCs) in the atmosphere leads to the formation of OH radicals and many other oxidants such as HONO. These compounds are key species in photochemical cycles, which are responsible for the so called "photochemical smog". With OH radicals known to be as very powerful oxidizing agents for organic compounds, they are neglected in PAV and RTFOT testing methods. Here we demonstrate the power of UV and ROS ageing and highlight the importance of implementing these factors to the existing standardized testing methods. Last but not least, the penetration depth of oxidants into the binder is demonstrated with fluorescence spectroscopy. Characteristic chemical shifts which are unique for UV ageing have been found with progressive ageing that are missing in PAV and RTFOT ageing methods.

Photochemical ageing; UV; reactive oxygen species; fluorescence spectroscopy

https://publik.tuwien.ac.at/files/publik_301298.pdf