Numerical simulation of sulfate attack in cement based materials: Considering dynamic boundary calcium concentration

The coupling of sulphate attack and calcium leaching has been considered in various existing models. Whereas, the boundary condition in terms of calcium phases is commonly assumed as constant. In the present study, the runoff of calcium on the boundary is treated as a dynamic behaviour and according...

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Main Authors: Liyun Wu, Chaofan Yi, Qingge Feng, Xiao Huang, Zirong Mao
Format: Article
Language:English
Published: Elsevier 2024-12-01
Series:Case Studies in Construction Materials
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Online Access:http://www.sciencedirect.com/science/article/pii/S2214509524012439
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author Liyun Wu
Chaofan Yi
Qingge Feng
Xiao Huang
Zirong Mao
author_facet Liyun Wu
Chaofan Yi
Qingge Feng
Xiao Huang
Zirong Mao
author_sort Liyun Wu
collection DOAJ
description The coupling of sulphate attack and calcium leaching has been considered in various existing models. Whereas, the boundary condition in terms of calcium phases is commonly assumed as constant. In the present study, the runoff of calcium on the boundary is treated as a dynamic behaviour and accordingly, a flux-based boundary condition is proposed. Given this, the diffusion-reaction-damage model is established further to simulate the combined sulphate attack and calcium leaching in cement-based systems. By comparing the numerical results with experimental observations, the rationality of the proposed model has been fairly verified. Moreover, setting the boundary calcium concentration as zero or csatu has been found to either underestimate or overestimate the sulphate-induced degradation in cement-based systems, particularly within the region close to the exposed surface. The results obtained with the proposed flux-based condition are between them and are much more reasonable. Besides, under the coupling of sulphate attack and calcium leaching, the consumption of calcium ions in the formation of gypsum and ettringite is found much greater than the amount of runoff due to calcium leaching. This implies the dominant role of expansive cracking in such durability concerns. Through monitoring the cracking period for a certain clear cover, the result generated from the present study is between those modelled with the aforementioned two constant boundary calcium concentrations. This clearly confirms that fixing the boundary calcium concentration as a constant value will misestimate the service life of cement-based systems when subjected to the combined sulphate attack and calcium leaching.
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spelling doaj-art-664162be355146dd8b18beb7229b355a2024-12-11T05:56:38ZengElsevierCase Studies in Construction Materials2214-50952024-12-0121e04091Numerical simulation of sulfate attack in cement based materials: Considering dynamic boundary calcium concentrationLiyun Wu0Chaofan Yi1Qingge Feng2Xiao Huang3Zirong Mao4School of Civil Engineering and Architecture, Guangxi University, Nanning 530004, China; College of Architecture and Civil Engineering, Nanning University, Nanning 530200, ChinaSchool of Civil Engineering and Architecture, Guangxi University, Nanning 530004, ChinaSchool of Civil Engineering and Architecture, Guangxi University, Nanning 530004, China; School of Resource, Environment and Materials, Guangxi University, Nanning 530004, China; Corresponding author at: School of Civil Engineering and Architecture, Guangxi University, Nanning 530004, China.School of Resource, Environment and Materials, Guangxi University, Nanning 530004, ChinaSchool of Resource, Environment and Materials, Guangxi University, Nanning 530004, ChinaThe coupling of sulphate attack and calcium leaching has been considered in various existing models. Whereas, the boundary condition in terms of calcium phases is commonly assumed as constant. In the present study, the runoff of calcium on the boundary is treated as a dynamic behaviour and accordingly, a flux-based boundary condition is proposed. Given this, the diffusion-reaction-damage model is established further to simulate the combined sulphate attack and calcium leaching in cement-based systems. By comparing the numerical results with experimental observations, the rationality of the proposed model has been fairly verified. Moreover, setting the boundary calcium concentration as zero or csatu has been found to either underestimate or overestimate the sulphate-induced degradation in cement-based systems, particularly within the region close to the exposed surface. The results obtained with the proposed flux-based condition are between them and are much more reasonable. Besides, under the coupling of sulphate attack and calcium leaching, the consumption of calcium ions in the formation of gypsum and ettringite is found much greater than the amount of runoff due to calcium leaching. This implies the dominant role of expansive cracking in such durability concerns. Through monitoring the cracking period for a certain clear cover, the result generated from the present study is between those modelled with the aforementioned two constant boundary calcium concentrations. This clearly confirms that fixing the boundary calcium concentration as a constant value will misestimate the service life of cement-based systems when subjected to the combined sulphate attack and calcium leaching.http://www.sciencedirect.com/science/article/pii/S2214509524012439Sulphate attackCalcium leachingNumerical simulationFlux boundary conditionFilling-cracking effect
spellingShingle Liyun Wu
Chaofan Yi
Qingge Feng
Xiao Huang
Zirong Mao
Numerical simulation of sulfate attack in cement based materials: Considering dynamic boundary calcium concentration
Case Studies in Construction Materials
Sulphate attack
Calcium leaching
Numerical simulation
Flux boundary condition
Filling-cracking effect
title Numerical simulation of sulfate attack in cement based materials: Considering dynamic boundary calcium concentration
title_full Numerical simulation of sulfate attack in cement based materials: Considering dynamic boundary calcium concentration
title_fullStr Numerical simulation of sulfate attack in cement based materials: Considering dynamic boundary calcium concentration
title_full_unstemmed Numerical simulation of sulfate attack in cement based materials: Considering dynamic boundary calcium concentration
title_short Numerical simulation of sulfate attack in cement based materials: Considering dynamic boundary calcium concentration
title_sort numerical simulation of sulfate attack in cement based materials considering dynamic boundary calcium concentration
topic Sulphate attack
Calcium leaching
Numerical simulation
Flux boundary condition
Filling-cracking effect
url http://www.sciencedirect.com/science/article/pii/S2214509524012439
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AT qinggefeng numericalsimulationofsulfateattackincementbasedmaterialsconsideringdynamicboundarycalciumconcentration
AT xiaohuang numericalsimulationofsulfateattackincementbasedmaterialsconsideringdynamicboundarycalciumconcentration
AT zirongmao numericalsimulationofsulfateattackincementbasedmaterialsconsideringdynamicboundarycalciumconcentration