Finite element analysis of interfacial bonding performance between steel bars and alkali activated slag concrete

To achieve a simple， accurate， efficient， and effective simulation of the interfacial bond behavior between alkali activated slag concrete （AASC） and reinforcing steel， finite element models of rebar pull out tests were developed based on experimental results using the Abaqus finite element software. The bond slip behavior at the AASC-steel interface was simulated using three approaches： the Spring2 spring element method， the axial connector element method， and the contact interaction method. Finite element analyses of rebar pull out behavior were conducted and systematically compared. The results showed that the spring element method was able to accurately capture the bond slip response while maintaining a relatively simple modeling procedure and good numerical convergence. The connector element method improved modeling efficiency through automated node matching via scripting； however， because transverse and tangential deformations were neglected， convergence difficulties were sometimes observed. The contact interaction method simulated bond slip behavior by directly defining contact properties and was straightforward to implement， but the results were highly dependent on the definition of contact pairs and the selection of friction coefficients， leading to larger uncertainties. Overall， the spring element method demonstrated superior performance in both accuracy and computational efficiency and was therefore more suitable for simulating the interfacial bond behavior between alkali activated slag concrete and reinforcing steel.