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 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.

全世界每年都会产生大量的废料，例如塑料，对环境造成潜在的有害影响。与此同时，对沥青改性剂的需求逐年增加，因此这些类型的添加剂成本更高。因此，将大量可用的废塑料与沥青粘合剂结合起来作为增量剂或改性剂，可能会改善铺路材料的性能，同时限制处理的废物。虽然过去已经进行了几项流变学研究，但它们仅限于单一的研究工作，阻碍了这些研究的有价值结果之间的一致比较。为此原因，RILEM 技术委员会 279-WMR 的任务组 1 与 11 个国际机构建立了一项研究活动，以进行实验室间研究，以评估使用废聚乙烯 (PE) 作为沥青粘合剂添加剂的可能性。该研究探讨了 PE 材料和实验条件对沥青结合料流变性能的综合影响。为此，采用了常规测试（渗透值、软化点温度和 Fraass 断裂点温度）和使用动态剪切流变仪 (DSR) 的线性粘弹性表征。选择未老化的笔级 70/100 纯粘合剂作为参考粘合剂；由回收的废聚乙烯材料制成的 PE 颗粒和 PE 碎片用作聚合物添加剂。使用单一含量 (5%) 的 PE 颗粒和 PE 碎片将 PE 材料与参考粘合剂 (95%) 混合并制备两种 PE 改性粘合剂。结果表明，塑料改性剂的使用导致整体更高的复合剪切模量和软化点温度，同时降低了穿透值。在高温下观察到混合粘合剂的结果分散度更高，尤其是在相角方面。PE 改性粘合剂在实验室中表现出较差的再现性和低水平的可重复性。数据中的这种分散可能是由于塑料材料在高温下的不均匀分散造成的。相比之下，塑料形状和批次似乎影响有限。三种不同的流变行为，纯粘合剂、改性粘合剂和复合改性粘合剂，在实验室间结果中并基于简单的方差统计分析进行视觉识别。对数据的进一步分析表明，Glover Rowe (GR)参数可作为对 PE 改性粘合剂流变行为进行分类的敏感工具。建议对特定测试条件进行进一步的实验评估，例如高温下 DSR 的测量间隙，以促进了解它们对 PE 改性粘合剂流变行为的影响。