Rheological properties of asphalt binder modified with waste polyethylene : An interlaboratory research from the RILEM TC WMR

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Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2022-11
Major/Subject
Mcode
Degree programme
Language
en
Pages
16
Series
Resources, Conservation and Recycling, Volume 186
Abstract
Significant volumes of waste materials such as plastics is generated every year worldwide with a potentially harmful impact on the environment. At the same time, the demand for asphalt modifiers has seen an increase over the year with consequent higher costs for these types of additives. Therefore, combining large amounts of available waste plastics with asphalt binder as an extender or modifier would potentially improve the paving material properties while limiting the disposed waste. While several rheological studies have been performed in the past, they were restricted to single research efforts hindering a consistent comparison among the valuable results of these investigations. For this reason, the Task Group 1 of the RILEM Technical Committee 279-WMR established a research activity with 11 international institutions to conduct interlaboratory research to evaluate the possibility of using waste polyethylene (PE) as an additive in asphalt binder. The study addressed the combined impact of PE materials andexperimental conditions on the rheological properties of asphalt binder. For this purpose, conventional tests (penetration value, softening point temperature, and Fraass breaking point temperature) and the linear viscoelastic characterization using the Dynamic Shear Rheometer (DSR) were adopted. An unaged pen grade 70/100 neat binder was selected as the reference binder; PE-pellets and PE-shreds, produced from the recycled waste polyethylene materials, were used as the polymer additives. A single content (5%) of PE-pellets and PE-shreds was used to blend the PE material with the reference binder (95%) and prepare the two PE modified binders. Results indicate that the use of plastic modifiers leads to an overall higher complex shear modulus and softening point temperature while decreasing the penetration value. Higher dispersion in the results, especially in phase angles, was observed for blended binders at high temperatures. The PE modified binders exhibited poor reproducibility among laboratories and a low level of repeatability. Such a scatter in the data could result from an uneven dispersion of plastic material at high temperatures. In contrast, plastic shapes and batches appeared to have a limited impact. Three different rheological behaviors, neat binder, modified binder, and complex modified binder, were visually identified among the interlaboratory results and based on a simple statistical analysis of variance. Further analysis of the data suggested that the Glover Rowe (G-R) parameter can be used as a sensitive tool to classify the rheological behaviors of PE modified binders. Further experimental evaluation on specific testing conditions, such as measurement gaps of DSR at high temperatures, is recommended to advance the understanding of their influence on the rheological behavior of PE modified binders.
Description
Funding Information: The RILEM Technical Committee on Valorisation of Waste and Secondary Materials for Roads (TC 279-WMR) and the members of Task Group 1 are gratefully acknowledged. The authors would also like to thank Nynas AB and Swiss company Innorecycling for supporting the interlaboratory activity by providing reference neat binder and PE-pellets, PE-shreds additives. The contribution of the Swiss National Science Foundation ( 205121_178991 ) to the Swiss partners is also acknowledged. Funding Information: The RILEM Technical Committee on Valorisation of Waste and Secondary Materials for Roads (TC 279-WMR) and the members of Task Group 1 are gratefully acknowledged. The authors would also like to thank Nynas AB and Swiss company Innorecycling for supporting the interlaboratory activity by providing reference neat binder and PE-pellets, PE-shreds additives. The contribution of the Swiss National Science Foundation (205121_178991) to the Swiss partners is also acknowledged. Publisher Copyright: © 2022
Keywords
Asphalt binder, Dynamic shear rheometer (DSR), G-R parameter, Polyethylene (PE) plastics, Rheological property, Waste
Other note
Citation
Wang , D , Baliello , A , Poulikakos , L , Vasconcelos , K , Kakar , M R , Giancontieri , G , Pasquini , E , Porot , L , Tušar , M , Riccardi , C , Pasetto , M , Lo Presti , D & Cannone Falchetto , A 2022 , ' Rheological properties of asphalt binder modified with waste polyethylene : An interlaboratory research from the RILEM TC WMR ' , Resources, Conservation and Recycling , vol. 186 , 106564 . https://doi.org/10.1016/j.resconrec.2022.106564