Experimental study on mechanical properties of steel and steel fiber reinforced concrete beams

According to the construction difficulties in steel reinforced concrete (SRC) structures, rebar cages were discretized into steel fibers to form steel and steel fiber reinforced concrete (SSFRC) structures. The 18 SSFRC beams without rebar cages were tested under bending, and the effect of the steel fiber volume ratio (ρsf), shaped steel ratio (ρss), and shear span ratio (λ) on mechanical properties were investigated. Increasing ρsf could not only turn shearing failure and debonding failure into bending failure, and effectively reduce the sudden decrease of load, but also enhance the bearing capacity, ductility, and damage resistance of specimens to a certain extent. As the ρss ascended, the mechanical properties were obviously improved. However, ρsf should be accordingly increased to avoid adverse effects of excessive ρss. The specimen with small λ had the better bearing and energy dissipation capacity and poor ductility. A large λ meant that ρss and ρsf should be appropriately increased to prevent premature failure of specimens.