A Hydration based Model for Chloride Penetration into Slag blended High Performance Concrete

초록

To improve the chloride ingress resistance of concrete, slag is widely used as a mineral admixture in concrete industry. And currently, most of experimental investigations about non steady state diffusion tests of chloride penetration are started after fourweeks standard curing of concrete. For slag blended concrete, during submerged chloride penetration tests periods, binder reactionproceeds continuously, and chloride diffusivity decreases. However, so far the dependence of chloride ingress on curing ages arenot detailed considered. To address this disadvantage, this paper shows a numerical procedure to analyze simultaneously binderhydration reactions and chloride ion penetration process. First, using a slag blended cement hydration model, degree of reactions ofbinders, combined water, and capillary porosity of hardening blended concrete are determined. Second, the dependences of chloridediffusivity on capillary porosity of slag blended concrete are clarified. Third, by considering time dependent chloride diffusivityand surface chloride content, chloride penetration profiles in hardening concrete are calculated. The proposed prediction model isverified through chloride immersion penetration test results of concrete with different water to binder ratios and slag contents.

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