Browsing by Author "Kakar, Muhammad Rafiq"
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- Bituminous Binder and Bituminous Mixture Modified with Waste Polyethylene
A3 Kirjan tai muun kokoomateoksen osa(2023) Tušar, Marjan; Poulikakos, Lily D.; Kakar, Muhammad Rafiq; Pasquini, Emiliano; Pasetto, Marco; Porot, Laurent; Wang, Di; Cannone Falchetto, Augusto; Carter, Alan; Orozco, Gabriel; Riccardi, Chiara; Vasconcelos, Kamilla; Varveri, Aikaterini; Jing, Ruxin; Pinheiro, Gustavo; Hernando, David; Mikhailenko, Peter; Stoop, Jan; Wouters, Lacy; Miljković, Miomir; Orešković, Marko; Viscione, Nunzio; Veropalumbo, Rosa; Saboo, Nikhil; Lachance-Tremblay, Éric; Vaillancourt, Michel; Bueche, Nicolas; Dalmazzo, Davide; Moreno-Navarro, Fernando; Lo Presti, Davide; Giancontieri, GaspareRILEM TC-279 WMR task group TG 1 studied the performance of waste Polyethylene (PE) in bituminous binders and bituminous mixtures. Several laboratories participated in this study following a common protocol. Locally sources aggregates and bituminous binder and same source of waste PE were utilized. The binder experiments showed that at high temperatures, using MSCR tests, PE modified blends had better resistance to permanent deformation in comparison to the non modified binder. Whereas at intermediate temperatures, using the LAS tests, fatigue performance of the PE blends could withstand more loading cycles under low strains; however, it could sustain less loading cycles under high strains due to the increase in brittleness. Dry process was used for the mixture experiments in order to bypass the stability and inhomogeneity experience that was observed at the binder scale. The PE modified mixtures showed improved workability and increased strength. The higher the PE dosage, the higher the ITS increase with respect to the values measured for the control materials (i.e., without any plastic waste) thanks to the improved cohesion of the plastic modified mastic. The stiffness experiments tended to show an improved performance with a lower time dependence and a higher elasticity when plastic was added. The cyclic compression tests demonstrated a reduced creep rate along with a higher creep modulus thanks to the addition of PE; similar conclusions can be drawn from the experimental findings coming from wheel tracking test. Furthermore, acceptable and often improved moisture resistance was observed for PE modified materials. - Rheological properties of asphalt binder modified with waste polyethylene : An interlaboratory research from the RILEM TC WMR
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2022-11) Wang, Di; Baliello, Andrea; Poulikakos, Lily; Vasconcelos, Kamilla; Kakar, Muhammad Rafiq; Giancontieri, Gaspare; Pasquini, Emiliano; Porot, Laurent; Tušar, Marjan; Riccardi, Chiara; Pasetto, Marco; Lo Presti, Davide; Cannone Falchetto, AugustoSignificant 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 and experimental 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. - RILEM interlaboratory study on the mechanical properties of asphalt mixtures modified with polyethylene waste
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2022-11-15) Poulikakos, Lily D.; Pasquini, Emiliano; Tusar, Marjan; Hernando, David; Wang, Di; Mikhailenko, Peter; Pasetto, Marco; Baliello, Andrea; Cannone Falchetto, Augusto; Miljković, Miomir; Orešković, Marko; Viscione, Nunzio; Saboo, Nikhil; Orozco, Gabriel; Lachance-Tremblay, Éric; Vaillancourt, Michel; Kakar, Muhammad Rafiq; Bueche, Nicolas; Stoop, Jan; Wouters, Lacy; Dalmazzo, Davide; Pinheiro, Gustavo; Vasconcelos, Kamilla; Moreno Navarro, FernandoThis research aims to determine if the observed improvements using polyethylene (PE) waste in asphalt binder translate into better performance at the asphalt mixture scale in the laboratory environment while overcoming the stability and homogeneity issues experienced at the binder level. This is accomplished through a round-robin multinational experimental program covering four continents, with the active participation of eleven laboratories within the RILEM TC 279-WMR. PE modified AC16 mixtures were prepared employing the dry process using local materials with the PE waste provided by one source. Various mechanical tests were performed to investigate the compactability, strength, moisture sensitivity, stiffness and permanent deformation. Compared to the control mixtures, the following observations were made for PE modified mixtures: easier to compact, lower time dependence of stiffness, higher elastic behavior, lower creep rate, and higher creep modulus. Furthermore, cyclic compression test results showed that the resistance to permanent deformation is improved when using PE in asphalt mixtures, whereas the wheel tracking tests showed relatively similar or better results when 1.5% PE was added to the control mixture. The wheel tracking test results in water showed an increase in deformation with increasing PE content. The interlaboratory investigation showed that the use of PE as a performance-enhancing additive in asphalt pavements is a viable, environmentally friendly option for recycling waste plastic and could potentially reduce the use of polymer additives in asphalt.