In pavement engineering, the use of bio-binders and reclaimed asphalt (RA) promotes the principles of sustainability and circular economy, without penalizing or even improving the performance. In this regard, this study focuses on the “circular propensity” of bio-binders obtained by partially replacing a conventional bitumen with a bio-oil generated as a residue by the wood and paper industries. Specifically, the objectives are: 1) to assess the effectiveness of bio-binders in the hot recycling of traditional RA and 2) to evaluate, in a long-term perspective, their recyclability potential. For this purpose, two severely aged binders (one “RAP” binder recovered from reclaimed asphalt and one laboratory-produced “Bio-RAP” binder) and two fresh binders (one bio-binder and one bitumen) are blended to reproduce four hot recycled binders. The mechanical behaviour and the aging susceptibility of these blends are compared to those of a control virgin bitumen. The experimental investigation includes conventional tests, rheological testing and modelling (modified CAM model) as well as chemical analysis (Fourier transform infrared spectroscopy). The main results indicate that the hot recycling of reclaimed bio-asphalt (bio-RA) may lead to mixtures less susceptible to cracking as compared to the recycling of conventional RA, as well as the use of bio-binders in the hot recycling of conventional RA may be beneficial in terms of cracking. Even though the blends with the bio-binder are characterized by a lower aging rate, the permanent deformation behaviour of all the recycled blends studied is comparable in unaged and short-term aged conditions, i.e. the circumstances under which rutting is usually a concern. Finally, the recycled blends show significantly lower aging susceptibility than the control bitumen. Overall, these results suggest that the bio-binders studied are effective in the hot recycling of RA and 100% recyclable, and their use in asphalt pavements can lead to significant technical and environmental benefits.

在路面工程中，生物粘结剂和再生沥青（RA）的使用促进了可持续性和循环经济的原则，而不会影响甚至改善性能。在这方面，本研究着重于通过用木材和造纸工业产生的作为残留物的生物油部分替代常规沥青而获得的生物粘合剂的“圆形倾向”。具体而言，目标是：1）评估生物粘合剂在传统RA热回收中的有效性，以及2）从长远角度评估其可回收性潜力。为此，将两种严重老化的粘合剂（一种从再生沥青中回收的“ RAP”粘合剂和一种由实验室生产的“ Bio-RAP”粘合剂）和两种新鲜的粘合剂（一种生物粘合剂和一种沥青）混合在一起，以生产四种热回收材料。粘合剂。将这些混合物的机械性能和老化敏感性与对照原始沥青的力学性能和老化敏感性进行比较。实验研究包括常规测试，流变测试和建模（改进的CAM模型）以及化学分析（傅立叶变换红外光谱）。主要结果表明，与常规RA的回收相比，再生生物沥青（bio-RA）的热回收可能导致混合物不易破裂，并且在常规热回收中使用生物粘合剂RA可能对破解有帮助。即使具有生物粘合剂的共混物的特征在于较低的老化率，但在未老化和短期老化的条件下，所研究的所有回收共混物的永久变形行为都是可比的，即 通常需要关注车辙的情况。最后，与对照沥青相比，回收的混合物显示出明显更低的老化敏感性。总体而言，这些结果表明，所研究的生物粘合剂在RA的热循环和100％可循环利用方面均有效，它们在沥青路面中的使用可带来重大的技术和环境效益。