Study of Concrete Moisture Transfer Characteristics in the Presence of the Concrete Micro–Meso Structure Effect

Water and water transfer are the keys of the concrete durability problem; the non-uniform moisture transfer caused by the concrete micro–meso structure has a great effect on the drying shrinkage crack, transfers of inimical ions, etc. For the non-uniform moisture transfer problem, a multi-scale conc...

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Main Authors: Xiaogang Zhang, Shuhua Zhang, Bofu Chen, Bin Tian, Xiaochun Lu, Bobo Xiong, Zhao Pan
Format: Article
Language:English
Published: MDPI AG 2025-02-01
Series:Applied Sciences
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Online Access:https://www.mdpi.com/2076-3417/15/4/1774
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author Xiaogang Zhang
Shuhua Zhang
Bofu Chen
Bin Tian
Xiaochun Lu
Bobo Xiong
Zhao Pan
author_facet Xiaogang Zhang
Shuhua Zhang
Bofu Chen
Bin Tian
Xiaochun Lu
Bobo Xiong
Zhao Pan
author_sort Xiaogang Zhang
collection DOAJ
description Water and water transfer are the keys of the concrete durability problem; the non-uniform moisture transfer caused by the concrete micro–meso structure has a great effect on the drying shrinkage crack, transfers of inimical ions, etc. For the non-uniform moisture transfer problem, a multi-scale concrete moisture diffusion coefficient model which can consider the effect of Knudsen diffusion was established and verified based on the moisture transfer mechanism of porous medium and the concrete micro–meso structure characteristics. The effects of pore structure, the interfacial transition zone, and aggregate on the concrete moisture diffusion coefficient were studied based on the model, and the non-uniform moisture transfer characteristics and differences in concrete wetting and drying were analyzed via simulations. The results show that the moisture transfers more easily via the pores ranging from 10 nm to 100 nm, the effect of Knudsen diffusion increases with the increasing water-to-cement ratio and decreases with the increasing relative moisture, and Knudsen diffusion is also an effect factor which causes the moisture diffusion coefficient to increase with the increase in moisture. Moisture transfers more easily via the interfacial transition zone at the meso-level and causes a “flow around” phenomenon. The “S” growth relation between the moisture diffusion coefficient and relative moisture can consider the differences in the moisture diffusion coefficient under wetting and drying conditions to a certain extent, which makes concrete wet faster than dry. In addition, the jumping growth of the moisture diffusion coefficient in the relation also leads to an “inflection point” in the concrete moisture distribution.
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spelling doaj-art-a4a6515f8bee4de7881fca22ef6b7a662025-08-20T03:12:10ZengMDPI AGApplied Sciences2076-34172025-02-01154177410.3390/app15041774Study of Concrete Moisture Transfer Characteristics in the Presence of the Concrete Micro–Meso Structure EffectXiaogang Zhang0Shuhua Zhang1Bofu Chen2Bin Tian3Xiaochun Lu4Bobo Xiong5Zhao Pan6College of Hydraulic and Environmental Engineering, Three Gorges University, Yichang 443002, ChinaThe Seventh Geological Brigade of Hubei Geological Bureau, Yichang 443000, ChinaCollege of Hydraulic and Environmental Engineering, Three Gorges University, Yichang 443002, ChinaCollege of Hydraulic and Environmental Engineering, Three Gorges University, Yichang 443002, ChinaCollege of Hydraulic and Environmental Engineering, Three Gorges University, Yichang 443002, ChinaCollege of Hydraulic and Environmental Engineering, Three Gorges University, Yichang 443002, ChinaCollege of Hydraulic and Environmental Engineering, Three Gorges University, Yichang 443002, ChinaWater and water transfer are the keys of the concrete durability problem; the non-uniform moisture transfer caused by the concrete micro–meso structure has a great effect on the drying shrinkage crack, transfers of inimical ions, etc. For the non-uniform moisture transfer problem, a multi-scale concrete moisture diffusion coefficient model which can consider the effect of Knudsen diffusion was established and verified based on the moisture transfer mechanism of porous medium and the concrete micro–meso structure characteristics. The effects of pore structure, the interfacial transition zone, and aggregate on the concrete moisture diffusion coefficient were studied based on the model, and the non-uniform moisture transfer characteristics and differences in concrete wetting and drying were analyzed via simulations. The results show that the moisture transfers more easily via the pores ranging from 10 nm to 100 nm, the effect of Knudsen diffusion increases with the increasing water-to-cement ratio and decreases with the increasing relative moisture, and Knudsen diffusion is also an effect factor which causes the moisture diffusion coefficient to increase with the increase in moisture. Moisture transfers more easily via the interfacial transition zone at the meso-level and causes a “flow around” phenomenon. The “S” growth relation between the moisture diffusion coefficient and relative moisture can consider the differences in the moisture diffusion coefficient under wetting and drying conditions to a certain extent, which makes concrete wet faster than dry. In addition, the jumping growth of the moisture diffusion coefficient in the relation also leads to an “inflection point” in the concrete moisture distribution.https://www.mdpi.com/2076-3417/15/4/1774concretemoisture transferKnudsen diffusionmicro–meso structuremoisture diffusion coefficient
spellingShingle Xiaogang Zhang
Shuhua Zhang
Bofu Chen
Bin Tian
Xiaochun Lu
Bobo Xiong
Zhao Pan
Study of Concrete Moisture Transfer Characteristics in the Presence of the Concrete Micro–Meso Structure Effect
Applied Sciences
concrete
moisture transfer
Knudsen diffusion
micro–meso structure
moisture diffusion coefficient
title Study of Concrete Moisture Transfer Characteristics in the Presence of the Concrete Micro–Meso Structure Effect
title_full Study of Concrete Moisture Transfer Characteristics in the Presence of the Concrete Micro–Meso Structure Effect
title_fullStr Study of Concrete Moisture Transfer Characteristics in the Presence of the Concrete Micro–Meso Structure Effect
title_full_unstemmed Study of Concrete Moisture Transfer Characteristics in the Presence of the Concrete Micro–Meso Structure Effect
title_short Study of Concrete Moisture Transfer Characteristics in the Presence of the Concrete Micro–Meso Structure Effect
title_sort study of concrete moisture transfer characteristics in the presence of the concrete micro meso structure effect
topic concrete
moisture transfer
Knudsen diffusion
micro–meso structure
moisture diffusion coefficient
url https://www.mdpi.com/2076-3417/15/4/1774
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