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 (rho(sf)), shaped steel ratio (rho(ss)), and shear span ratio (lambda) on mechanical properties were investigated. Increasing rho(sf) 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 rho(ss) ascended, the mechanical properties were obviously improved. However, rho(sf) should be accordingly increased to avoid adverse effects of excessive rho(ss). The specimen with small lambda had the better bearing and energy dissipation capacity and poor ductility. A large lambda meant that rho(ss) and rho(sf) should be appropriately increased to prevent premature failure of specimens.