Faßbender Sabine, Oeser Markus
Institute of Highway Engineering, RWTH Aachen University, Mies-van-der-Rohe-Str. 1, 52074 Aachen, Germany.
Materials (Basel). 2020 Mar 9;13(5):1235. doi: 10.3390/ma13051235.
A polyurethane-based rubber-modified layer within a road superstructure leads to absorption of traffic emissions. Noise emissions have quite a negative effect on society, as they lead to high stress levels and health risks for people. Therefore, constructional methods of noise-reducing road layers have been developed before. This research paper focuses on the questions whether the existing noise-reducing road constructions, which have a low durability, can be optimized in terms of a longer duration while simultaneously maintaining the noise-reducing effects. Within this research, a large parametric study contributed to an optimal solution of a noise-reducing and durable layer. We found that noise absorption is mainly dependent of the void content of the pavement and its flexibility. Also, a result is that the durability of a road layer is based on the properties of the binder as well as the composition of the mixture, i.e., the grading curve. As we used polyurethane binders within our mixtures, which have a low dependency on regular environmental temperatures after their complete chemical reaction, we can imply a low temperature dependence of the entire polyurethane asphalt mixture. Based on these results, the construction of a noise-reducing and durable road layer is a great solution. The application of such road layers leads to lower traffic emissions at major hotspots. These might be urban highways, where the infrastructure is too tight to build noise barriers, enclosures or tunnels.
道路上层结构中基于聚氨酯的橡胶改性层可吸收交通排放物。噪音排放对社会有相当大的负面影响，因为它们会导致人们产生高压力水平并带来健康风险。因此，之前已经开发出了降低噪音道路层的施工方法。本研究论文关注的问题是，现有的降噪道路结构耐久性较低，能否在延长使用寿命的同时保持降噪效果的前提下进行优化。在这项研究中，一项大型参数研究促成了一种降噪且耐用层的最优解决方案。我们发现，噪音吸收主要取决于路面的孔隙率及其柔韧性。此外，一个结果是道路层的耐久性基于粘结剂的性能以及混合料的组成，即级配曲线。由于我们在混合料中使用了聚氨酯粘结剂，其在完全化学反应后对常规环境温度的依赖性较低，所以我们可以推断整个聚氨酯沥青混合料对温度的依赖性也较低。基于这些结果，构建一种降噪且耐用的道路层是一个很好的解决方案。这种道路层的应用可减少主要热点地区的交通排放。这些热点地区可能是城市高速公路，那里的基础设施空间有限，无法建造隔音屏障、隔音罩或隧道。
