Permeability of slag concrete under repeated loading

Repeated loading five times was applied to concrete specimens using WHY series full automatic testing machine, the maximum loading was 0.4f_cy (axial compressive strength) and 0.8f_cy. In order to analyze the relationship between slag replacement, loading, and permeation time, the chloride ion concentration in anode chamber was measured during the accelerated chloride permeation test of concrete after unloading. The chloride ion concentration in the anode chamber was linear with respect to time after a stage time. The results show that, in the case of 0.4f_cy, the permeability of concrete increases significantly. The permeability of concrete has a further increment when the stress level rises from 0.4f_cy to 0.8f_cy. Adding ground slag in concrete can inhibit the increment of concrete permeability due to the loading. The inhibition increases with the replacement of ground slag when the replacement is no more than 30%, while the inhibition decreases when the replacement is 40%.