Fiber polymer has been extensively used to improve the mechanical properties and durability of concrete. However, the studies of the effect of fiber polymer on the dynamic performance of recycled aggregate concrete (RAC) is still very limited. In this study, we prepared two types of RAC formulations: RAC reinforced with basalt fibers (BFs) and RAC reinforced with polypropylene fibers (PPs), and compared the effects of fiber types and contents on the air void content, workability (slump), mechanical properties (compressive and flexural strength), dynamic characteristics (dynamic modulus of elasticity and damping ratio), and chloride resistance of RAC. The experimental results showed that the air void content and slump value decreased with the increase of replacement percentage of RCA and fiber contents. Adding PPs provided a more negative effect on the slump of RAC than BFs. The mixtures containing 0.2% PPs and BFs both obtained the highest flexural strength. The addition of PPs was more effective than BFs in improving the damping ratio of RAC, and the mixtures containing 0.3% PPs and BFs both obtained the highest damping ratio. Compared to the RAC without addition of fiber, the charge passed of specimen with addition of PPs approximately increased by 45%, while the specimen with addition of BFs approximately increased by 30%, when the fiber content was 0.3%. This study demonstrates the potential of using fiber to promote the dynamic properties of RAC.

中文翻译：

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玄武岩和聚丙烯纤维增强再生骨料混凝土的动态特性及耐氯性

纤维聚合物已被广泛用于改善混凝土的力学性能和耐久性。然而，关于纤维聚合物对再生骨料混凝土（RAC）动力性能影响的研究仍然非常有限。在本研究中，我们制备了两种类型的 RAC 配方：玄武岩纤维 (BFs) 增强的 RAC 和聚丙烯纤维 (PPs) 增强的 RAC，并比较了纤维类型和含量对气孔含量、可加工性（坍落度）、 RAC 的机械性能（压缩和弯曲强度）、动态特性（动态弹性模量和阻尼比）和耐氯化物性。试验结果表明，随着RCA置换率和纤维含量的增加，孔隙率和坍落度值降低。与 BFs 相比，添加 PPs 对 RAC 的暴跌产生更大的负面影响。含有 0.2% PPs 和 BFs 的混合物都获得了最高的弯曲强度。PPs的加入比BFs更能有效提高RAC的阻尼比，且含有0.3%PPs和BFs的混合物均获得最高的阻尼比。与不添加纤维的RAC相比，当纤维含量为0.3%时，添加PPs的试样的电荷通过率大约增加了45%，而添加BFs的试样的电荷通过率大约增加了30%。这项研究证明了使用纤维来促进 RAC 的动态特性的潜力。PPs的加入比BFs更能有效提高RAC的阻尼比，且含有0.3%PPs和BFs的混合物均获得了最高的阻尼比。与不添加纤维的RAC相比，当纤维含量为0.3%时，添加PPs的试样的电荷通过率大约增加了45%，而添加BFs的试样的电荷通过率大约增加了30%。这项研究证明了使用纤维来促进 RAC 的动态特性的潜力。PPs的加入比BFs更能有效提高RAC的阻尼比，且含有0.3%PPs和BFs的混合物均获得了最高的阻尼比。与不添加纤维的RAC相比，当纤维含量为0.3%时，添加PPs的试样的电荷通过率大约增加了45%，而添加BFs的试样的电荷通过率大约增加了30%。这项研究证明了使用纤维来促进 RAC 的动态特性的潜力。