Effect of W/B to the Time Dependent Chloride Diffusion in Concrete with GGBS

This paper studied the influence of water to binder ratio to time dependent diffusion coefficients in concrete exposed to marine environments. And a refined diffusion model which considered the time dependent apparent diffusion coefficients and time dependent surface chloride concentration was established. It was found that both apparent diffusion coefficients and surface chloride concentration are time dependent and both are significantly influenced by water to binder ratio. Apparent diffusion decrease with time while surface chloride concentration increase with time. but water to binder ratio has similar influence to the constant of time dependent diffusion coefficients and the parameter of time dependent surface chloride concentration.

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Effective and Apparent Diffusion Coefficients of Chloride Ions and Chloride Binding Kinetics Parameters in Mortars: Non-Stationary Diffusion–Reaction Model and the Inverse Problem

Materials ◽

10.3390/ma13235522 ◽

2020 ◽

Vol 13 (23) ◽

pp. 5522

Author(s):

Jerzy Jasielec ◽

Jakub Stec ◽

Krzysztof Szyszkiewicz-Warzecha ◽

Artur Łagosz ◽

Jan Deja ◽

...

Keyword(s):

Diffusion Coefficients ◽

Reaction Model ◽

Chloride Ions ◽

Diffusion Reaction ◽

Chloride Diffusion ◽

Accurate Estimation ◽

Chloride Binding ◽

Apparent Diffusion Coefficients ◽

Binding Isotherms ◽

Apparent Diffusion

A non-equilibrium diffusion–reaction model is proposed to describe chloride transport and binding in cementitious materials. A numerical solution for this non-linear transport with reaction problem is obtained using the finite element method. The effective chloride diffusion coefficients and parameters of the chloride binding are determined using the inverse method based on a diffusion–reaction model and experimentally measured chloride concentrations. The investigations are performed for two significantly different cements: ordinary Portland and blast furnace cements. The results are compared with the classical diffusion model and appropriate apparent diffusion coefficients. The role of chloride binding, with respect to the different binding isotherms applied, in the overall transport of chlorides is discussed, along with the applicability of the two models. The proposed work allows the determination of important parameters that influence the longevity of concrete structures. The developed methodology can be extended to include more ions, electrostatic interactions, and activity coefficients for even more accurate estimation of the longevity.

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Influence on GGBS to Time Dependent Chloride Diffusion Coefficient of HPC

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.243-249.5703 ◽

2011 ◽

Vol 243-249 ◽

pp. 5703-5710 ◽

Cited By ~ 1

Author(s):

Lu Guang Song ◽

Wei Sun ◽

Jian Ming Gao ◽

Yun Sheng Zhang

Keyword(s):

Diffusion Coefficient ◽

Diffusion Coefficients ◽

Great Influence ◽

Chloride Diffusion ◽

Chloride Diffusion Coefficient ◽

Time Dependency ◽

Apparent Diffusion Coefficients ◽

Granulated Blast Furnace Slag ◽

Apparent Diffusion ◽

Furnace Slag

This paper investigates the influences of dosage of ground granulated blast furnace slag (GGBS) (0%, 20%, 40%, 60% and 80%) to chloride diffusion coefficient. And the time dependency of apparent diffusion coefficient as the submerging time from 60 days to 360days has also been studied. The result shows that the addition of GGBS into concrete has great influence on the chloride diffusion. The diffusion coefficients of the mixes containing GGBS decrease rapidly with time than that of the mix PC Control. But there were little differences of the values of apparent diffusion coefficients among the mixes SL20, SL40 and SL60. The addition of GGBS in concrete has great influence on the time dependency of concrete. And the concrete which has 40%-60% replacement of GGBS has greater ability to resist the diffusion of chloride than other replacement.

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