钢纤维表面处理对混凝土减振性能的影响

Effect of steel fiber surface treatment on vibration damping performance of concrete

摘要:

为了优化混凝土控制振动的能力,提出了3种通过钢纤维表面改性提高其阻尼从而提升减振性能的方法。将钢纤维使用硅烷偶联剂、乳化沥青、聚氨酯进行表面改性处理,通过振动激励法、显微扫描电镜探究了钢纤维表面处理对混凝土时域曲线、阻尼比、能量耗散因子和微观形貌的影响,并分析其影响规律与机理。研究结果表明:3种表面处理均可增大钢纤维混凝土的阻尼比,均在掺量（体积分数）为1%的钢纤维时阻尼比最大；乳化沥青对钢纤维表面处理试验组减振性能提升最为显著,当掺量为1%时,其保持抗压强度为50.5 MPa的同时,阻尼比提升为对照组的221%；钢纤维表面乳化沥青层增大了基体对振动能量的消耗,提高了混凝土的阻尼性能；钢纤维与基体的界面调制方法决定了减振方式,其中硅烷偶联剂表面处理钢纤维可增大纤维与基体黏结力,通过提高纤维与基体的滑移耗能提高振动过程的耗能,聚氨酯表面处理钢纤维可增大钢纤维和基体界面的形变能力和黏弹性,从而提升振动传播过程的耗能,乳化沥青表面处理钢纤维混凝土同时利用这两种方式进行振动过程中的耗能。研究成果提供了一种既满足实际施工中的工作性和强度要求,又具有优良减振性能的混凝土配合比,作为一种新型地铁道床材料减振方式,可为未来的工程实践和研究提供参考。

Abstract:

To optimize the vibration control capability of concrete, this paper proposes several methods to enhance the damping performance of steel fibers through surface modification, thereby improving the vibration reduction effect. Steel fibers were surface-modified using silane coupling agent, emulsified asphalt, and polyurethane. The effects of steel fiber surface treatment on the time-domain curve, damping ratio, energy dissipation factor, and microstructure of concrete were investigated via vibration excitation method and scanning electron microscopy (SEM), and the influencing laws and mechanisms were analyzed.The results show that all three surface treatments can increase the damping ratio of steel fiber-reinforced concrete, with the maximum damping ratio achieved when the steel fiber volume content is 1%. The emulsified asphalt-treated group exhibits the most significant improvement in vibration reduction performance: at a 1% volume content, it maintains a compressive strength of 50.5 MPa while increasing the damping ratio to 221% of the control group. The emulsified asphalt layer on the steel fiber surface enhances the vibration energy dissipation of the matrix, thereby improving the damping performance of concrete.The interface modulation method between steel fibers and the matrix determines the vibration reduction mechanism: silane coupling agent treatment enhances the bonding force between fibers and the matrix, improving energy dissipation during vibration by increasing slip energy consumption at the fiber-matrix interface; polyurethane treatment enhances the deformability and viscoelasticity of the fiber-matrix interface, thereby increasing energy dissipation during vibration propagation; emulsified asphalt treatment achieves energy dissipation through both mechanisms simultaneously.This study provides a concrete mix ratio that meets the workability and strength requirements in practical construction while exhibiting excellent vibration reduction performance. As a new vibration reduction method for subway ballast bed materials, it can serve as a reference for future engineering practices and research.