González Alvaro, Norambuena-Contreras José, Poulikakos Lily, Varela María José, Valderrama Jonathan, Flisch Alexander, Arraigada Martín
Department of Construction Engineering and Management, School of Engineering, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna, Santiago 4860, Chile.
LabMAT, Department of Civil and Environmental Engineering, University of Bío-Bío, Avenida Collao, Concepción 1202, Chile.
Materials (Basel). 2020 Dec 16;13(24):5731. doi: 10.3390/ma13245731.
This paper reports part of an international research project with the long-term aim of developing more sustainable asphalt mixture with crack-healing properties by the addition of recycled metallic waste from industrial sources. Specifically, this article presents an evaluation of the physical, thermophysical, and mechanical properties of asphalt mixtures with metallic fiber obtained from recycled tires for crack-healing purposes. Detailed results on the crack-healing of asphalt mixtures will be reported in a second article. Results showed a small reduction on the bulk density and increase in the air voids content was quantified with increasing fiber contents. The experimental results showed that mixing and compaction was more difficult for higher fiber contents due to less space for the bitumen to freely flow and fill the voids of the mixtures. Computed tomography (CT) results allowed to identify clustering and orientation of the fibers. The samples were electrically conductive, and the electrical resistivity decreased with the increase of the fiber content. Fiber content had a direct effect on the indirect tensile stiffness modulus (ITSM) and strength (ITS) that decreased with increasing temperature for mixtures and with increase in fiber content. However, the indirect tensile strength ratio (ITSR) was within acceptable limits. In short, results indicate that fibers from recycled tires have a potential for use within asphalt mixtures to promote crack-healing.
本文报道了一个国际研究项目的部分内容，该项目的长期目标是通过添加工业来源的回收金属废料来开发具有裂缝自愈性能的更可持续的沥青混合料。具体而言，本文对用于裂缝自愈目的的含回收轮胎金属纤维的沥青混合料的物理、热物理和力学性能进行了评估。关于沥青混合料裂缝自愈的详细结果将在第二篇文章中报道。结果表明，随着纤维含量的增加，体积密度略有降低，空隙率增加。实验结果表明，对于较高的纤维含量，由于沥青自由流动和填充混合料空隙的空间较小，搅拌和压实更加困难。计算机断层扫描（CT）结果有助于识别纤维的聚集和取向。样品具有导电性，且电阻率随纤维含量的增加而降低。纤维含量对间接拉伸刚度模量（ITSM）和强度（ITS）有直接影响，对于混合料，它们随温度升高和纤维含量增加而降低。然而，间接拉伸强度比（ITSR）在可接受范围内。简而言之，结果表明回收轮胎纤维有潜力用于沥青混合料中以促进裂缝自愈。
