尼龙纤维对橡胶混凝土力学性能的影响

Effects of Nylon Fiber on Mechanical Properties of Rubber Concrete

摘要:

为提升橡胶混凝土的力学性能，制备了尼龙纤维增强橡胶混凝土（NFRC），并对比了尼龙纤维和NaOH表面改性对橡胶混凝土力学性能的影响。结果表明：NaOH表面改性可有效改善橡胶与水泥基体的界面结构，使橡胶混凝土抗压强度提升8.1%；尼龙纤维能显著补偿橡胶颗粒掺入引起的强度衰减，当尼龙纤维掺量φ_NF（体积分数）为1.0%时，增强效果最优，与普通橡胶混凝土相比，该掺量下NFRC的抗压强度、劈裂抗拉强度、抗折强度、冲击延性指数分别提高了14.7%、34.0%、27.1%、59.89%，抗冲击破坏次数增加了5.61倍，并使其冲击破坏模式由脆性破坏转变为延性破坏；尼龙纤维通过桥接、拔出和断裂等机制在裂纹发展阶段有效增韧，并与橡胶颗粒协同作用，改善了混凝土的断裂性能。

Abstract:

To enhance the mechanical properties of rubber concrete， nylon fiber-reinforced rubber concretes（NFRC） were prepared. The effects of nylon fiber and NaOH surface modification on mechanical properties of rubber concretes were investigated. The results indicate that NaOH surface modification effectively improves the interface structure between rubber and the cement matrix， resulting in an 8.1% increase in the compressive strength of rubber concrete. Nylon fibers significantly compensate for the reduction in strength induced by rubber particles.When the content （volume fraction） of nylon fibers φ_NF is 1.0%， the reinforcing effect reaches the optimum level. Compared with ordinary rubber concrete， the compressive strength， splitting tensile strength， flexural strength， and impact ductility index of the NFRC with 1.0% nylon fibers increase by 14.7%， 34.0%， 27.1%， and 59.89%， respectively， while the number of impact failure cycles rises by 5.61 times. Moreover， the impact failure mode is transformed from brittle to ductile. Nylon fibers enhance toughness through mechanisms such as bridging， pulling out， and fracturing at various stages of crack development， working synergistically with rubber particles to improve the fracture behavior of concrete.