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硅酸盐通报 ›› 2026, Vol. 45 ›› Issue (9): 3043-3054.DOI: 10.16552/j.cnki.issn1001-1625.2026.0279

• 水泥混凝土 • 上一篇    下一篇

冻融循环时多场耦合下混凝土中氯离子传输的数值模拟研究

李凯1,2(), 高长天1, 史才军1,2   

  1. 1.湖南大学土木工程学院,绿色先进土木工程材料及应用技术湖南省重点实验室,长沙 410082
    2.湖南省绿色先进土木工程材料国际科技创新合作基地,长沙 410082
  • 收稿日期:2026-03-25 修订日期:2026-05-06 出版日期:2026-09-15 发布日期:2026-10-09
  • 作者简介:李 凯(1988—),男,博士,副教授。主要从事水泥基材料耐久性的研究。E-mail:kaili@hnu.edu.cn
  • 基金资助:
    国家自然科学基金面上项目(52178205);湖南省自然科学基金面上项目(2025JJ50291)

Numerical Simulation on Chloride Ion Transport in Concrete under Freeze-Thaw Cycles by Considering Multi-Field Coupling

LI Kai1,2(), GAO Changtian1, SHI Caijun1,2   

  1. 1.Key Laboratory for Green and Advanced Civil Engineering Materials and Application Technology of Hunan Province,College of Civil Engineering,Hunan University,Changsha 410082,China
    2.International Science and Technology Innovation Center for Green and Advanced Civil Engineering Materials of Hunan Province,Changsha 410082,China
  • Received:2026-03-25 Revised:2026-05-06 Published:2026-09-15 Online:2026-10-09

摘要:

服役状态下混凝土材料容易遭受冻融循环、干湿交替、氯盐侵蚀等多重破坏作用,所以揭示多场耦合作用下氯离子传输机制对准确开展混凝土耐久性评估具有重要意义。本工作首先基于不规则骨料堆积结构,构建了混凝土三相细观模型,然后使用多物理场数值模拟方法探究了冻融循环次数、温度范围、冻结时长与融化时长比、盐溶液浓度对氯离子传输行为的影响。研究结果表明,考虑冻融过程中温度与孔隙含冰量的梯度分布及水分对流效应后,模拟结果与试验数据十分吻合。冻融循环对孔隙结构造成的损伤,在100次循环后使氯离子扩散系数提升了34.40倍;更大温度范围、冻结时长与融化时长比都有助于提升水分流速,而后者还可使孔隙冰对传输路径的阻碍作用减弱,氯离子传输过程因而得到促进;盐溶液浓度升高虽然会减弱水分对流效应,但增大了氯离子浓度梯度并抑制了孔隙冰生成,氯离子传输速率总体仍会增加。

关键词: 混凝土, 冻融循环, 多场耦合, 数值模拟, 水分传输, 氯离子传输, 耐久性

Abstract:

Concrete in service is often subjected to various harsh environments, including freeze-thaw cycles, alternate wetting and drying and chloride ion corrosion. Consequently, the issues of chloride salt erosion in concrete gradually become prominent and attract a lot of attention in recent years, since it acts as a serious threaten to the service life of concrete materials. Once freeze-thaw cycles happen, a periodic variation in the temperature does not only induce the transition of water into ice, but also results in a damaged pore structure and occurred water convection phenomenon. On one hand, the changes in temperature can directly affect the diffusion rate of chloride ion. On the other hand, the pore ice would block the transport channels of chloride ion, while the water convection effect induced by pore pressure and cryosuction pressure could promote the movement of chloride ion as well. Moreover, the aggregates of arbitrary shape in concrete also have a significant influence on the transport of chloride ion. Unfortunately, existing studies often simply treat concrete as a homogeneous material, and its actual shape on chloride ion transport is just ignored. Hence, in order to reveal the mechanism of chloride ion transport in concrete under multi-field coupling effects during freeze-thaw cycles, the morphological characteristics of real aggregates and multi-field coupling effects during freeze-thaw cycles should be all taken into account.In this work, a three-phase concrete model at meso-scale was first built in which irregular aggregate packing structure was carefully considered. A multiphysics numerical simulation method was then employed to study the chloride transport process in concrete under different conditions. The model’s accuracy and applicability were compared to experimental results and a good agreement was observed in case the gradient distributions of temperature and pore ice content during freeze-thaw cycles, along with the water convection effect were taken into account. Afterwards, the influences of the number of freeze-thaw cycles, temperature range, freeze-thaw time ratio and salt solution concentration on the behavior of chloride ion transport were further investigated.The results show a damaged pore structure caused by freeze-thaw effect after 100 cycles enables the specimen’s chloride ion diffusion coefficient to be enlarged by 34.40 times. In case the water convection effect is neglected, the obtained chloride transport depth and average concentration in concrete are reduced by 5 mm and 1.16 times, respectively. Meanwhile, a wider temperature range and a higher freeze-thaw time ratio contribute to an increased temperature gradient inside concrete during thawing, thereby enhancing water flow velocity, but the latter can also diminish the blocking effect of pore ice on transport path, so the chloride ion transport process is still facilitated. Although an increase in salt solution concentration would weaken the water convection effect, the chloride concentration gradient is raised and the formation of pore ice is inhibited, resulting in an elevated chloride ion transport rate.

Key words: concrete, freeze-thaw cycle, multi-field coupling, numerical simulation, water transport, chloride ion transport, durability

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