Experimental Study and Degradation Analysis on Interfacial Shear Modulus of Steel and Steel Fiber-Reinforced Concrete Composite Structure

To address the problems of mutual interference between shaped steel and reinforcement bars and the difficulty of concrete pouring in the construction of steel-reinforced concrete (SRC) composite structure, the steel and steel fiber-reinforced concrete (SSFRC) composite structure without rebars was proposed. Bond behavior between the shaped steel and steel fiber reinforced concrete is the basis to ensure two kinds of materials work together. 20 square specimens were designed and tested by push-out test to study the bond performance and shear modulus of the interface between the shaped steel and steel fiber reinforced concrete. The effects of steel fiber ratio ( ρ sf ), embedded length ( L e ), and concrete cover thickness ( C ss ) on the interfacial shear modulus ( G ) were analyzed quantitatively. The degradation law of G was studied by defining the degradation variable of interfacial shear modulus ( D a ). The results show that the increase of ρ sf contributes to the ascent in G , and the loading end displacement ( D ) at the end of degradation related to G also increase. With the rise of L e , the value of G decreases gradually and the D becomes larger when G starts to deteriorate. In addition, there is a positive correlation between G and C ss . Besides, the higher C ss leads to a slower degradation process of G .