To address the construction difficulties of steel reinforced concrete structures and fully leverage material performance,the rebar cage was discretized into randomly distributed steel fibers.Steel fiber reinforced concrete was concentrated in the compression zone to form the locally composite steel and steel fiber reinforced concrete structure.Four-point bending tests were carried out on 18 beam specimens with different steel fiber volume fractions(ρsf),shear span ratios(λ),concrete protective layer thicknesses for upper and lower parts of steel compression flange(Css and Csv),and shaped steel specifications(Is).The effects of these test parameters on failure modes,load-deflection curves,and failure symmetry of specimens were analyzed.The results show that increasingρsf had a positive effect on improving the interface bonding performance for specimens with smaller λ(1.5 or 1.7),and the failure mode changed from interface failure to bending-torsion failure.To ensure that the concrete protective layer provides sufficient"grip-wrap effect"on the shaped steel and avoid or weaken the adverse effects of bending and torsion deformation,Css and Csv should increase simultaneously with Is.The deflection degradation coefficient was obtained by Gaussian distribution fitting,and the deflection when the specimen's overall performance began to seriously degrade was predicted.
维普
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