Numerical analysis on corrosion and mechanical performance of shear stud connector in concrete

Abstract

Geometric shape of shear stud connector plays an important role on its connecting capacity in steel-composite structures. Recent application of steel–concrete structures showed the degradation of structural performance due to aggressive medium from environment. Available research indicated that the presence of chloride ions in concrete induced depassivation on the surface of steel shear stud connector and resulted in its corrosion accordingly. Thus, it is essential to obtain the corroded shape of shear stud connector for further accurate assessing structural performance of steel–concrete composite structure. As the focus of this paper, based on Fick's second law and Butler-Volmer equation, a quantitative simulation method for reaction of corrosion in steel–concrete composite structures was introduced and discussed. Wherein, two steps of this approach were listed. Firstly, mass transportations of chloride ion, oxygen and hydroxide were simulated for their concentration for preparation of electrochemical reaction. Secondly, electrochemical reaction of Ferrum with presence of oxygen and water, catalyzed by chloride ion, was numerically simulated. Furthermore, two cases of ingression of chloride ion into concrete were discussed for the influence of boundary condition on structural characteristics of steel–concrete composite structure. Random distribution of aggregate in concrete was considered. Result of numerical simulation indicated that, corrode shape of shear stud connector was related to configuration of boundary condition and different pull-out performance were obtained by finite element analysis. Moreover, degradation of mechanical properties of shear stud during its service life were provided.