Improvement of flexural and cyclic performance of bridge deck slabs by utilizing steel fiber reinforced concrete (SFRC)

Abstract

This paper aims at investigating how the utilization of steel fiber reinforced concrete (SFRC) improves the flexural and cyclic responses of reinforced concrete bridge deck slabs. Firstly, one plain concrete slab and two SFRC slabs reinforced by mill-cut steel fibers and corrugated steel fibers, respectively, were tested under cyclic loads. The load–deflection responses, cyclic deformation behaviors, strain and crack evolutions are discussed. Subsequently, a theoretical analysis method of SFRC slab is introduced and validated. Using this method, the effects of key strength parameters of SFRC, i.e. fL, fR1, fR4, on load–deflection responses and deck slab design indices (i.e. slab height, areas of steel rebars, slab span) are clarified through parametric analysis. Results demonstrate that using SFRC in deck slabs significantly enhances the cyclic deformation performance, decreases the residual strain in the slab section, and improves the crack behavior by reducing residual crack width and increasing cracking stiffness. An increase in fL and fR1 can enhance service capacity Ps and flexural stiffness ks, as well as improve design indices under the service requirement, whilst the influences of fR4 are minor. Increasing fR1 and fR4 can enhance ultimate capacity Pu and improve design indices under the ultimate requirement, whereas the effects of fL are rather limited. Since the use of mill-cut steel fibers produces higher fL and fR1 than corrugated steel fibers, the former has better advantages to enhance Ps and ks. These results may provide references for the application of SFRC in bridge deck slabs.