The use of asphalt concrete (AC) for railway trackbed layers is now well established and, in some countries, even accepted as a standard solution for high–speed or high–load lines. To date constructed track sections which incorporate AC trackbed layers use AC mixtures which contain only up to 30 % of reclaimed asphalt (RA). This limit is most likely a remnant of the past when the amount of RA in AC mixtures was limited as a precaution to compensate for the lack of experience with RA. Nowadays, the trend and the aspiration for using higher percentages of RA in AC mixtures is increasing and railway engineering should embrace this. This paper presents the results of ongoing research to this end. The first part of the paper describes a laboratory–based investigation into the required design properties of an AC mixture made of 100 % of RA. The second part describes the construction and continuous assessment of a trial section on an operational mainline in the Czech Republic. The results show that it is possible to construct an AC trackbed layer with a high percentage (70%) of RA using only simple mechanization and that such a layer provides an effective formation treatment, significantly reduces the loss of track geometry, provides more uniform track support and protects the subgrade from the adverse effects of temperature changes and the ingress of rainwater. The paper concludes that an AC mixture for a railway trackbed layer should be treated as a specific type of AC mixture, with its own set of design criteria, and invites further research into the feasibility of using AC with high percentage of RA not only as a remediation technique but as a standard trackbed solution.

如今，在铁路轨道床层中使用沥青混凝土（AC）的做法已经很成熟，在某些国家甚至被接受为高速或高负荷线路的标准解决方案。迄今为止，结合有AC履带层的已建造轨道段使用的AC混合物最多仅包含30％的再生沥青（RA）。当限制AC混合物中RA的量作为补偿​​RA经验不足的预防措施时，此限制很可能是过去的遗留物。如今，在AC混合物中使用更高比例的RA的趋势和愿望正在增加，铁路工程应接受这一点。本文介绍了为此目的正在进行的研究的结果。本文的第一部分描述了基于实验室的研究，研究了由100％RA制成的AC混合物所需的设计特性。第二部分介绍了捷克共和国某业务干线上试验段的建设和持续评估。结果表明，仅通过简单的机械化就可以构建具有高百分比（70％）RA的AC履带层，并且该层可提供有效的地层处理，显着减少轨道几何形状的损失，提供更均匀的轨道支持并保护路基免受温度变化和雨水进入的不利影响。本文的结论是，应将铁路轨道床层的交流混合气作为一种特定类型的交流混合气，并按其自身的设计标准进行处理，并鼓励人们进一步研究使用高比例RA的交流混合气的可行性，而不仅仅是将其作为一种混合物。修复技术，但作为标准的跟踪解决方案。