A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Water and salt migration characterization in NaHCO3 saline soils during unidirectional freezing conditions
Abstract In cold regions, the eutectic action of the NaHCO3-H2O binary system during the freezing process affects the migration of water and salt in NaHCO3 saline soils. This study aims to investigate the migration of water and salt in open and closed systems, utilizing unidirectional freezing tests with different salt contents. By considering the phase diagram of pore solution and phase transition theory, two phase-change paths can be observed in NaHCO3 saline soils during freezing. These paths result in different migration patterns for water and salt, depending on the salt and water content conditions of the samples. The theoretical and experimental results both validate that water migrates from the unfrozen zone towards the eutectic action and ice crystallization zone during the freezing process. Under low-salinity conditions, salt migrates from the ice crystallization zone towards the eutectic action and unfrozen zone. Conversely, under high-salinity conditions, salt migrates from the unfrozen zone towards the eutectic action. Moreover, it is observed that a high salt content hinders water migration.
Highlights The water-salt migration characteristics of NaHCO3 saline soils was investigated by unidirectional freezing test. The eutectic temperature and eutectic concentration of NaHCO3 saline soil during freezing were determined. The effect of initial water and salt content on water-salt migration was analyzed from the point of phase transition.
Water and salt migration characterization in NaHCO3 saline soils during unidirectional freezing conditions
Abstract In cold regions, the eutectic action of the NaHCO3-H2O binary system during the freezing process affects the migration of water and salt in NaHCO3 saline soils. This study aims to investigate the migration of water and salt in open and closed systems, utilizing unidirectional freezing tests with different salt contents. By considering the phase diagram of pore solution and phase transition theory, two phase-change paths can be observed in NaHCO3 saline soils during freezing. These paths result in different migration patterns for water and salt, depending on the salt and water content conditions of the samples. The theoretical and experimental results both validate that water migrates from the unfrozen zone towards the eutectic action and ice crystallization zone during the freezing process. Under low-salinity conditions, salt migrates from the ice crystallization zone towards the eutectic action and unfrozen zone. Conversely, under high-salinity conditions, salt migrates from the unfrozen zone towards the eutectic action. Moreover, it is observed that a high salt content hinders water migration.
Highlights The water-salt migration characteristics of NaHCO3 saline soils was investigated by unidirectional freezing test. The eutectic temperature and eutectic concentration of NaHCO3 saline soil during freezing were determined. The effect of initial water and salt content on water-salt migration was analyzed from the point of phase transition.
Water and salt migration characterization in NaHCO3 saline soils during unidirectional freezing conditions
Li, Sitan (author) / Chen, Huie (author) / Chen, Zongfang (author)
2023-06-22
Article (Journal)
Electronic Resource
English
Study on water-salt phase transition of saline soils during freezing
| Elsevier | 2024
Salt expansion and frost heave of freezing saline soils
| British Library Conference Proceedings | 1997