Civil and Infrastructure Engineering, RMIT University, Melbourne, Victoria 3001, Australia.
Construction Management and Engineering, University of Twente, 7500 AE Enschede, the Netherlands.
Sci Total Environ. 2021 Jul 15;778:146187. doi: 10.1016/j.scitotenv.2021.146187. Epub 2021 Mar 8.
Many road construction and maintenance projects are increasingly using recycled material as pavement material. Most of the times, generic sustainability evaluations are ascribed to recycled products without fully considering their performance. The potential environmental benefits of various alternatives can be analytically evaluated with Life Cycle Assessment while many performance indicators can be found through laboratory and field tests. However, it is highly uncommon for these two approaches to be combined in the same assessment methodology and most of the analyses rely on one or the other. Trading off between environmental advantages and performance and durability in the field is considered of utmost importance when evaluating construction alternatives, especially on large projects. This study utilizes recycled plastic packaging films for bitumen modification. The recycled polyolefin blend is a combination of linear low-density polyethylene and low-density polyethylene (LLDPE/LDPE). LLDPE/LDPE was added in bitumen at various dosages (i.e., from 3% to 12% by weight of the bitumen) to assess the effect of recycled LLDPE/LDPE on the binder physio-chemical, rheological and thermal performance. In addition to the various laboratory performance tests, the environmental sustainability of the alternatives was evaluated through an LCA study. Finally, the outcomes from the two approaches (laboratory performance and environmental impact assessment) were combined via grey relational analysis to identify the best overall alternative. It was found that the storage stability of LLDPE/LDPE modified blends varied from 6 °C to 57 °C whereas the storage stability value of A35P was 2 °C. Softening point of bitumen was 44.1 °C which improved to 55.7-104.1 °C at different content of LLDPE/LDPE. The melting temperature of LLDPE/LDPE modified blends was 100.22, 101.44, 101.87 and 102.49 for LLDPE/LDPE-3%, LLDPE/LDPE-6%, LLDPE/LDPE-9% and LLDPE/LDPE-12%. The methodology highlighted in the paper can be easily adapted to other scenarios, hence facilitating multi-attribute decision-making processes when incorporating recycled materials in roads and leading to better informed decisions.
许多道路建设和维护项目越来越多地将回收材料用作路面材料。大多数情况下，通用的可持续性评估归因于回收产品，而没有充分考虑其性能。各种替代品的潜在环境效益可以通过生命周期评估进行分析评估，而许多性能指标可以通过实验室和现场测试找到。然而，这两种方法很少在同一评估方法中结合使用，而且大多数分析都依赖于一种或另一种方法。在评估建筑替代品时，特别是在大型项目中，权衡环境优势与现场性能和耐久性至关重要。本研究利用回收塑料包装薄膜来改性沥青。回收的聚烯烃共混物是线性低密度聚乙烯和低密度聚乙烯（LLDPE/LDPE）的组合。LLDPE/LDPE 以不同的剂量（即，占沥青重量的 3%至 12%）添加到沥青中，以评估回收 LLDPE/LDPE 对粘合剂物理化学、流变学和热性能的影响。除了各种实验室性能测试外，还通过生命周期评估 (LCA) 研究评估了替代品的环境可持续性。最后，通过灰色关联分析将两种方法（实验室性能和环境影响评估）的结果结合起来，以确定最佳的整体替代品。结果发现，LLDPE/LDPE 改性共混物的储存稳定性从 6°C 到 57°C 不等，而 A35P 的储存稳定性值为 2°C。沥青的软化点为 44.1°C，在不同 LLDPE/LDPE 含量下提高到 55.7-104.1°C。LLDPE/LDPE 改性共混物的熔点分别为 100.22、101.44、101.87 和 102.49，用于 LLDPE/LDPE-3%、LLDPE/LDPE-6%、LLDPE/LDPE-9%和 LLDPE/LDPE-12%。本文中强调的方法可以轻松应用于其他情况，因此在将回收材料纳入道路时促进多属性决策过程，并做出更明智的决策。
