A possible valorization of reclaimed asphalt pavement (RAP) aggregates resulting from flexible roads maintenance consists of introducing them in cement concrete compositions for road construction. However, experimental results reported in the literature show a relative loss in mechanical and elastic properties due to the RAP aggregate’s incorporation. The main objective of the present study is to improve the compressive strength of RAP concretes by using silica fume (SF) as a mineral admixture. Experimental results show that SF increases the compressive strength of RAP concretes as well as conventional concretes. A scanning electron microscopy analysis was carried out on specimens in order to confirm the conclusion of the experimental study. Finally, a 2 2 factorial design allowed the individual and combined effects of RAP and SF introduction on the compressive strength of 91-day concretes to be quantified. This approach has shown that 30% partial aggregate substitution and 10% silica fume reinforcement would give the concrete the characteristics required for its use in the construction of reinforced rigid pavements. Therefore, recycling RAP aggregates and SF in cement concretes can be considered as an ecological approach that respects the environment, within a sustainable development context of road networks.

中文翻译：

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硅粉提高再生沥青路面混凝土的抗压强度

由灵活的道路维护产生的再生沥青路面 (RAP) 骨料的可能增值包括将它们引入用于道路建设的水泥混凝土组合物中。然而，文献中报道的实验结果表明，由于 RAP 骨料的掺入，机械和弹性性能的相对损失。本研究的主要目的是通过使用硅粉 (SF) 作为矿物外加剂来提高 RAP 混凝土的抗压强度。实验结果表明，SF 增加了 RAP 混凝土以及常规混凝土的抗压强度。对样品进行了扫描电子显微镜分析，以确认实验研究的结论。最后，2 2 因子设计允许量化 RAP 和 SF 引入对 91 天混凝土抗压强度的单独和组合影响。这种方法表明，30% 的部分骨料替代和 10% 的硅粉加固将使混凝土具有用于建造加固刚性路面所需的特性。因此，在道路网络的可持续发展背景下，回收水泥混凝土中的 RAP 骨料和 SF 可以被视为一种尊重环境的生态方法。