Statistical analysis of chloride concentration distribution in concrete by a meso-scale model considering irregular shape aggregates: Fid-Bau Portal

Statistical analysis of chloride concentration distribution in concrete by a meso-scale model considering irregular shape aggregates

Jiang, Zhi-Lu / Qian, Zhi-Wei / Gu, Xiang-Lin / Zhu, Ji-Hua / Long, Wu-Jian / Xing, Feng

Abstract

Highlights • Chloride diffusion model with 3D irregular aggregate particles was proposed. • Aggregate shapes affect standard deviation of chloride concentration notably. • Critical time dispersion was decreased by using aggregates with higher sphericity. • Effects of aggregate shapes on critical chloride depths were studied. • Cover thickness was designed using spatial variability of critical chloride front.

Abstract The purpose of this paper is to investigate the probabilistic characteristics of chloride concentration distribution in concrete with irregular aggregates by a numerical method. Chloride diffusion was simulated based on a three-dimensional geometrical model considering random distribution of irregular aggregate particles. The simulated results indicated that the chloride diffusivity increased as the aggregate sphericity and flatness ratio increased. The standard deviation of chloride concentration at the same depth could be decreased by using aggregates with a higher sphericity or a more isotropic aggregate. The heterogeneity of the concrete’s meso-structure should be considered for evaluation of the critical time in steel corrosion in concrete under chloride environment. Critical time dispersion could by decreased by using aggregates with higher sphericity. The concrete cover thickness was designed considering the spatial variability of critical chloride front. This research confirms that the spatial variability of aggregate distribution should be considered if maximum critical chloride depths were used as the cover thickness.