A Study on Analytical Technique of Chloride Diffusion considering Characteristics of Mixture Design for High Performance Concrete using Mineral Admixture

With increased significance of durability of concrete structures, intensive studies on numerical analysis for deterioration of the concrete structures due to the chloride attack have been carried out. In order to obtain required durability of concrete structures, use of mineral admixture is also considered as a measurement in material. For the diffusivity characteristics which is changing along with micro structure formation of hydrated cement paste, it is necessary to consider time-dependent change of micro-structure of concrete. But in general analysis for chloride penetration inside concrete, the target concrete is mainly made of ordinary portland cement (OPC) and the prediction of amount of free chloride contents are not evaluated because total chloride contents are only used in the general chloride penetration analysis. This study is on analytical technique of chloride diffusion considering characteristics of mixture design for HPC using mineral admixture. In order to evaluate chloride behavior of the HPC using mineral admixture, the, so called, multi-component heat hydration model (MHHM) and micro structure formation model (MSFM) for early-age concrete are used. The change of chloride binding capacity due to the use of mineral admixture is expressed in the function of porosity and chloride diffusivity is also obtained as a function of the porosity using the models. Finally, numerical results obtained from the analysis using derived diffusivity and chloride binding capacity are compared with experiment data obtained from experimental results.