Chloride Ion Transport Simulation of Concrete with Added Glazed Hollow Bead Considering Thermal Damage

[Purposes] The crack damage to tunnel lining structure caused by fire generally poses a significant challenge to the maintenance of its structural durability. [Methods] To address this issue, a convex polygon aggregate numerical model of concrete with glazed hollow beads (GIC) consisting of coarse aggregate, mortar, and the interface transition zone was established through the interactive use of MATLAB and COMSOL softwares. The numerical simulation was conducted to investigate the chloride ion transport behavior considering the effect of high temperature and the model validity was then verified. According to the theory of steel reinforcement depassivation life, an evaluation mechanism of post-disaster service life parameter impact was further established. [Findings] The results show that with the increase of the volume fraction of glazed hollow beads, the decrease of the thickness of interfacial transition zone, and the increase of the maximum aggregate diameter, the post-disaster residual service life is improved. Especially, the effect of glazed hollow beads is particularly significant. [Conclusions] According to parameter analysis, the durability limit state function considering the influence of high temperature is finally established through single factor correlation analysis and multivariate nonlinear analysis methods. This study could provide a reference for building structure design and post-disaster life assessment in practical engineering.