Failure mechanism and bearing capacity analysis of steel fiber steel reinforced concrete(SFSRC) beams.

In order to put forward the failure mechanism and calculation method of bearing capacity of Steel Fiber and Steel Reinforced Concrete (SFSRC) composite beams, the mechanical performance tests of 33 SFSRC specimens were carried out with steel fiber content, shear span ratio, stirrup ratio and longitudinal reinforcement configuration as variables, and the failure mechanism of specimens under three different failure modes of shear failure, bending failure and interface slip failure is revealed, the typical load deflection curves of three failure modes are summarized. According to the theory of crack strength enhancement of steel fiber, a formula for calculating the anti slip strength of the interface between steel and steel fiber concrete is proposed. By means of regression analysis, the distribution coefficients of steel fiber reinforced concrete, steel shape and reinforcement of composite beams are determined, and the calculation formula of shear strength of composite beams is proposed. Based on the interface failure mechanism of specimens, the bond influence coefficient is introduced, and the bearing capacity calculation formula of composite beam with normal section bending failure and interface slip failure are proposed. Through comparison and verification, the calculation results of the above formula are in good agreement with the test results. • Research on Steel Fibers Steel Reinforced Concrete composite beams under four point bending. • The failure mechanisms corresponding to the three failure modes were revealed. • The formulas for calculating the interfacial bonding strength were proposed based on the interfacial bonding failure mechanism. • The section steel and SFRC in the rebar-free composite beams were in good agreement before the specimens entered the failure stage. • The calculated method for predicting the bearing capacity of SFSRC beams are proposed and correctness has been verified. [ABSTRACT FROM AUTHOR]