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

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.