Failure mechanism on sulfate attack and dissolved corrosion of diseased tunnel lining structure

To study the corrosion failure mechanism of tunnel lining structure subjected to sulfate attack and dissolved corrosion, site investigation was carried out on a diseased in Chongqing. The products were analyzed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) Fourier transform infrared (FTIR) spectroscopy. results showed that had been exposed groundwater containing substantial concentrations salts (SO 4 2- , HCO 3 - et al.) for many years, resulted concrete strength lower than its design value. formation thaumasite made lose completely. Concrete would be destroyed when crystallization pressure exceeded tensile concrete. also appeared which cement stone density reduce.