Experimental Study and Damage Analysis of Interface of Steel Reinforced Concrete

Research purposes: The research on the interfacial bonding relationship of steel reinforced concrete composite structures is mostly carried out by finite element simulation or fitting analysis using the results of the experimental results. And, the influence of interface damage on bonding is not considered in theoretical research. In order to obtain the interface cohesion model which can truly reflect the interface bonding condition, based on the results of the steel reinforced concrete push-out test, the interface cohesion model is proposed and the concept of interface damage is introduced. The evolution law of interface stress in the whole process of interface failure is analyzed. Research conclusions:(1) The ultimate interface bearing capacity of different specimens varies with interface bonding condition. After the interface failure, the wrapping force of concrete to section steel remains basically unchanged and the dynamic friction coefficient between concrete and steel is constant. (2) The state of the interface can be divided into three states: elastic state, damage state, and peeling state. The recommended values of the interface cohesion model parameters are: interface bond capacity 0.818 7 MPa; interface friction resistance 0.391 4 MPa. (3) The whole interface failure process will go through five stages: fully elastic stage, elastic-damage stage, elastic-damage-slip stage, damage-slip stage and slip stage. (4) In the fully elastic stage, the minimum bonding force appears near the free end, not at the free end. (5) The research results can provide a reference for determining the interfacial bond relationship and the evolution law of interfacial stress in the design of steel reinforced concrete composite structures. © 2019, Editorial Department of Journal of Railway Engineering Society. All right reserved.