Experimental Investigation and Analytical Modeling of Chloride Diffusivity of Fly Ash Concrete

Zhang, Jian; Zhou, Xinzhu; Zheng, Jianjun; Ye, Hailong; Yang, Jin

doi:10.3390/ma13040862

Cited by 5 publications

(4 citation statements)

References 41 publications

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“…In [26,44,61], Equation ( 5) was used to calculate the effect of humidity on chloride diffusion. A small change in humidity will cause a considerable change in the diffusion coefficient of chloride ions based on Equation (5). There are limited studies focused on the randomness of humidity.…”

Section: Effect Of Randomness Of Temperature and Humidity On Corrosio...mentioning

confidence: 99%

“…Moreover, it is infeasible to obtain the probability distribution of the load bearing capacity directly by experimental methods, which will cost a large amount of resources. Many studies [1][2][3][4][5] have been conducted on chloride ion diffusion and steel corrosion using experimental or analytical methods, which provide the basis of probability calculation. Bohni [6] comprehensively explained the basic corrosion mechanisms in reinforced concrete structures.…”

Section: Introductionmentioning

confidence: 99%

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The Corrosion Probability and Flexural Strength of an RC Beam under Chloride Ingress Considering the Randomness of Temperature and Humidity

Pang

Zhu

et al. 2020

Materials

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The load capacity of reinforced concrete structure will decrease by chloride ingress in coastal region. In this paper, the corrosion probability and flexural strength of a typical reinforced concrete beam design under the influence of temperature and humidity was obtained by the Monte Carlo method. The relationship between flexural strength, temperature, relative humidity, and geometric parameters was established. The annual average temperature and relative humidity were treated as random variables together with the geometric size and concrete compressive strength. The corrosion probability and flexural strength in a wave splashing zone, coastal atmospheric zone, and offshore atmospheric zone were calculated. The results show that the corrosion probabilities of the three regions are obviously different. When the standard deviation of temperature is less than 1.5 °C, the temperature can be treated as a constant in the calculation of the concrete cracking probability in the wave splashing zone. A binary logistic regression formula was given to predict whether the randomness of temperature and humidity should be considered in the offshore atmospheric zone. When the standard deviation of the temperature is less than 1 °C, the temperature randomness has no significant effect on the flexural strength of beams in the wave splashing zone. The flexural strength distribution conforms to the normal distribution in the early stage of service and the Weibull distribution after concrete cracking.

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Section: Effect Of Randomness Of Temperature and Humidity On Corrosio...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Corrosion Probability and Flexural Strength of an RC Beam under Chloride Ingress Considering the Randomness of Temperature and Humidity

Pang

Zhu

et al. 2020

Materials

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“…In theoretical research, empirical formula, analytical method and numerical model are all the effective method for analyzing the diffusion performance of mineral admixture cement paste. Zhang et al [21] comprehensively evaluated the effects of w/b, C f and t on chloride transport via the combination of effective medium theory with penetration theory. Similarly, Damrongwiriyanupap et al [22] established an analytical method to predict the diffusivity of fly ash cement paste based on the porosity evolution.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation and Numerical Model for Chloride Diffusivity of Long-Age Fly Ash Cement Slurry

Chen,

Qi,

Jia

et al. 2023

Sustainability

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Fly ash is a by-product of coal-fired thermal power plants and offers great potential for the use of resources. To effectively improve the durability of reinforced concrete structures in marine environment and achieve waste to treasure, fly ash is widely used as a pozzolanic material due to its long-hydration characteristics and effects of micro-aggregate, micro-filling and secondary hydration. In this study, both the experimental investigation and numerical simulation are carried out to study the chloride transport characteristics of fly ash cement paste. The variation in chloride diffusivity with fly ash content, water-to-binder ratio and curing age up to 360 days is studied via accelerated conductivity measurement, and it is found that the above three experimental variables have a significant impact on the chloride diffusivity. For the influence of the dosage of fly ash, the optimum dosage is 30%. By introducing specific rules for the particle distribution, the fresh fly ash cement paste is first made. Based on the volume change characteristics of fly ash and cement particles after hydration, the vector hydration model of fly ash cement paste is established by considering the water shortage effect caused by hydration layer interference. After the accuracy of this hydration model is verified by the results from third-party experiments, the random walk algorithm is proposed to calculate the diffusion coefficient of the reconstructed mineral admixture cement paste. By comprehensive comparison with the experimental results from the third-party and self-conducted experiments, the numerical model for predicting the chloride diffusivity of fly ash cement paste is verified.

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“…For civil engineering infrastructure located in a severe natural environment, the chloride diffusion coefficient is one of the important parameters to access the durability and design of reinforced concrete [1][2][3]. A great deal of engineering practice, laboratory research, and theoretical analysis have confirmed that the factors influencing the chloride ingression into concrete include the ratio of water to binder, the content and the shape of aggregate, and the interface transition zone (ITZ) [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Analytical Solution for Chloride Diffusivity of Concrete with Aggregate Shape Effect

et al. 2021

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In view of the key role of chloride diffusivity in evaluating concrete durability, it is very important to determine this parameter accurately by an effective approach. This paper establishes an analytical solution for chloride diffusivity of concrete that can consider the aggregate shape. In this approach, the aggregate shape is simulated as an ellipse and the equivalent model is applied to calculate the chloride diffusivity of equivalent aggregate composed of interface transition zone (ITZ) and aggregate. With resort to this model, at the meso scale, the concrete can be reduced from the original three-phase composition to the two-phase one (i.e., equivalent aggregates and cement paste). Based on the mesostructure of concrete that consisted of randomly dispersed equivalent elliptical aggregates and cement paste, the generalized Maxwell’s approach is formed to determine the chloride diffusivity of concrete. The corresponding chloride diffusion test is conducted and the thickness of ITZ is reasonably determined as 0.04 mm by SEM test. By comparing with the experimental data, the accuracy of the analytical solution is confirmed. Finally, the impact of aggregate shape on chloride diffusivity is discussed. The analytical results show that the chloride diffusivity has a reduction with the increase of aggregate content or decrease of aspect ratio.

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Experimental Investigation and Analytical Modeling of Chloride Diffusivity of Fly Ash Concrete

Cited by 5 publications

References 41 publications

The Corrosion Probability and Flexural Strength of an RC Beam under Chloride Ingress Considering the Randomness of Temperature and Humidity

The Corrosion Probability and Flexural Strength of an RC Beam under Chloride Ingress Considering the Randomness of Temperature and Humidity

Experimental Investigation and Numerical Model for Chloride Diffusivity of Long-Age Fly Ash Cement Slurry

Analytical Solution for Chloride Diffusivity of Concrete with Aggregate Shape Effect

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