Time-Fractional Model of Chloride Diffusion in Concrete: Analysis Using Meshless Method

Ling Yao,Guoli Gong,Lixia Ren

doi:10.1155/2020/4171689

Ling Yao, Guoli Gong + Show 1 more

Open Access

https://doi.org/10.1155/2020/4171689

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Abstract

Chloride diffusion is the major factor that affects the life of concrete structures. The time-fractional order equation can be used to describe anomalous diffusion in reinforced concrete. In this work, a time-fractional model of chloride diffusion is solved via the meshless method. The Element-Free Galerkin (EFG) meshless method does not require meshing. One-dimensional and two-dimensional numerical examples are presented. Numerical results are in good agreement with theoretical solutions. The initiation time of corrosion is predicted in the presented model. Simulation results are compared with experimental data. The good agreement between EFG and experimental data indicates that time-fractional chloride diffusion in concrete can be modeled effectively by using the EFG method. This method is beneficial for further research on anomalous chloride diffusion in concrete.

Highlights

Reinforced concrete (RC) structures in coastal areas may suffer from rebar corrosion, and chloride ingression is the main factor that affects the durability of concrete structures [1,2,3,4]
The concrete material is not uniform and stable; some observers have found that the actual chloride diffusion process does not satisfy the traditional diffusion model and the chloride diffusion process exhibits time-dependent feature in engineering practice, which is called anomalous diffusion [6, 7]. e chloride diffusion mechanism in concrete is highly complicated because of wicking, chloride binding, permeation, and absorption, this case is an anomalous diffusion process, in which particles diffuse slower than the normal diffusion and its time-dependent features cannot be accurately reflected by traditional models [8]
Results come from the time-fractional chloride (TFC) model in the Element-Free Galerkin (EFG) method and the traditional chloride (TC) model calculated by the MWLS method, respectively

Summary

Introduction

Reinforced concrete (RC) structures in coastal areas may suffer from rebar corrosion, and chloride ingression is the main factor that affects the durability of concrete structures [1,2,3,4]. The EFG meshless method is used to solve the time-fractional model of chloride diffusion in concrete. 4. Numerical Examples e application of the time-fractional model of the EFG meshless method is illustrated using 1D and 2D examples of chloride diffusion in concrete.

Experimental data TFC TC

Conclusions