The permeability of SO42− and Cl− in concrete under the effect of seepage flow and stress fields

The ultrasonic velocity in concrete and the concentrations of ions at different depths along the directional flow of ion erosion were measured under the joint effect of seepage flow and stress fields. The permeability of sulfuric acid and chloride ions in concrete under different pressure head and load were analyzed (pressure head and load are perpendicular to each other). The results show that the concentrations of chloride ion and sulfate ion in different depths of concrete were increased to a certain extent either under the water head pressure or load effect. The differences in water head can induce the variation of ions concentration in the surface layer of concrete and the influenced depth can reach up to 60 mm. The load imposed a similar effect on the ions concentration of different layers and the directions of ion erosion, respectively. The ultrasonic testing results of corroded concrete are consistent with the results of ions concentration measured by spectrometry.