Research on diffusion model prediction based on time-varying sulfate ion concentration on concrete surface
To explore the corrosion damage of concrete under sulfate attack.By considering the time-varying law of the concentration of SO42-on the concrete surface,improving the existing diffusion-reaction equations,combining cement hydration,corrosion product filling and damage degree functions,a concrete damage model under sulfate erosion is established.Comsol Multiphysics was used to simulate the SO42-concentration of each cross-section of concrete under different sulfate concentrations and different erosion ages,and the calculated values of the model were compared with the measured values.The results show that under the erosion conditions of sulfate concentration of 5%and 10%,the maximum error between the calculated value and the measured value considering the time-varying process of SO42-concentration on the concrete surface is 17.46%and 19.69%,respectively.Through the established prediction model of the maximum depth of SO42-eroded concrete,it is found that the maximum erosion depth of sulfate eroded concrete increases rapidly in the early stage of erosion,and gradually slows down with the extension of erosion age,so as to provide reference for the durability evaluation of concrete.
concretesulfate erosiontime-varying surface ion concentrationdepth prediction
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