Construction materials research is consistently striving to improve sustainability, in the reduction of virgin materials by use of otherwise landfilled materials of the same purpose. Crumb rubber (CR) from end-of-life tires and polyethylene terephthalate (PET) from post-consumer liquid containers are two of the most commonly circulating forms of waste in the urban environment. This study investigated the replacement of semi-dense asphalt (SDA) sand by untreated mechanically shredded CR and PET, at 2.5 and 5.1% respectively by total mass of aggregates. The mixtures were evaluated by compactability, indirect tensile strength (ITS), fracture energy (FE), water sensitivity by ITS ratio (ITSR%), surface texture and acoustic absorption tests. After compaction, the CR and PET samples experienced an elastic rebound effect, which resulted in the air voids being higher than expected. Also, the PET samples required more compaction energy. The ITS, FE and ITSR% were significantly reduced with CR replacement, while the PET mixture performed similar to the control, especially in FE. The sound absorption was related more to the air voids than the material type, although the absorption coefficients of the SDA was not found to be significant. The CR reduced the texture level of the pavement significantly in comparison to the control, while texture level remained the same for the PET mixture, despite a difference in the porosity. Further studies were performed using a mixture replacing PET by aggregate volume at 5.1%, comparing it to the control SDA in terms of low temperature cracking and permanent deformation at 50 °C. While the compactability of the PET mixture was now similar to that of the control, the resistance to cracking and permanent deformation was lower. Although the PET mixture had some interesting ductility properties, the replacement of sand by CR and PET is not recommended, and the more common use as asphalt mixture modifiers with fairly low addition contents of around 1% is more sound.

建筑材料研究一直致力于提高可持续性，通过使用具有相同目的的其他填埋材料来减少原始材料。报废轮胎中的碎胶 (CR) 和消费后液体容器中的聚对苯二甲酸乙二醇酯 (PET) 是城市环境中两种最常见的循环废物形式。本研究调查了用未经处理的机械粉碎 CR 和 PET 替代半密沥青 (SDA) 砂，分别占集料总质量的 2.5% 和 5.1%。通过压实性、间接拉伸强度 (ITS)、断裂能 (FE)、ITS 比率 (ITSR%) 的水敏感性、表面纹理和吸声测试来评估混合物。压实后，CR 和 PET 样品经历了弹性回弹效应，这导致空隙率高于预期。此外，PET 样品需要更多的压实能量。ITS、FE 和 ITSR% 随 CR 替换显着降低，而 PET 混合物的表现与对照相似，尤其是在 FE 中。尽管没有发现 SDA 的吸声系数显着，但吸声与空气空隙的关系比材料类型更多。与对照相比，CR 显着降低了路面的质地水平，而 PET 混合物的质地水平保持不变，尽管孔隙率有所不同。使用混合物以5.1％的总体积代替PET的混合物进行了进一步的研究，将其与对照SDA进行了比较，发现其在50°C的低温下开裂和永久变形。虽然 PET 混合物的压实性现在与对照相似，但抗开裂和永久变形的能力较低。尽管 PET 混合物具有一些有趣的延展性，但不建议用 CR 和 PET 代替沙子，并且更常见的用作沥青混合物改性剂且添加量相当低（约 1%）更合理。