Revuelta David, Carballosa Pedro, García Calvo José Luis, Pedrosa Filipe
Institute for Construction Sciences Eduardo Torroja, CSIC, Serrano Galvache 4, 28033 Madrid, Spain.
Universidad Politécnica de Madrid, 28040 Madrid, Spain.
Materials (Basel). 2021 Oct 15;14(20):6111. doi: 10.3390/ma14206111.
Fiber reinforcement of concrete is an effective technique of providing ductility to concrete, increasing its flexural residual strength while reducing its potential for cracking due to drying shrinkage. There are currently a wide variety of industrial fibers on the market. Recycled steel fibers (RSF) from tires could offer a viable substitute of industrialized fibers in a more sustainable and eco-friendly way. However, mistrust exists among users, based on fear that the recycling process will reduce the performance, coupled with the difficulty of characterization of the geometry of the RSF, as a consequence of the size variability introduced by the recycling process. This work compares the behavior of RSF from tires compared with industrialized steel or polypropylene fibers, evaluating the fresh state, compressive strength, flexural residual strength, and drying behavior. The concept of Equivalent Fiber Length (EFL) is also defined to help the statistical geometrical characterization of the RSF. A microstructural analysis was carried out to evaluate the integration of the fiber in the matrix, as well as the possible presence of contaminants. The conclusion is reached that the addition of RSF has a similar effect to that of industrialized fibers on concrete's properties when added at the same percentage.
混凝土的纤维增强是一种为混凝土提供延性的有效技术，可提高其弯曲残余强度，同时降低因干燥收缩而开裂的可能性。目前市场上有各种各样的工业纤维。轮胎回收钢纤维（RSF）可以以更可持续和环保的方式成为工业化纤维的可行替代品。然而，由于担心回收过程会降低性能，再加上回收过程引入的尺寸变异性导致难以表征RSF的几何形状，用户之间存在不信任。这项工作比较了轮胎RSF与工业化钢纤维或聚丙烯纤维的性能，评估了新拌状态、抗压强度、弯曲残余强度和干燥性能。还定义了等效纤维长度（EFL）的概念，以帮助对RSF进行统计几何表征。进行了微观结构分析，以评估纤维在基体中的结合情况以及可能存在的污染物。得出的结论是，当以相同百分比添加时，RSF的添加对混凝土性能的影响与工业化纤维相似。
