Xu Lantian, Wang Yuchi, Wang Yuanzhan, Cheng Tianqi
State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Jinnan District, 135 Yaguan Road, Tianjin 300072, China.
Tianjin Research Institute for Water Transport Engineering, M.O.T., Binhai New District, 2618 Xingang 2nd Road, Tianjin 300456, China.
Materials (Basel). 2025 Aug 7;18(15):3708. doi: 10.3390/ma18153708.
Freeze-thaw damage is one of the most important factors affecting the durability of concrete in cold regions, and how to quantitatively characterize the effect of freeze-thaw cycles on the degree of damage of concrete is a widely concerning issue among researchers. Based on the hydraulic pressure theory, a new concrete freeze-thaw damage model was proposed by assuming the defect development mode of concrete during freeze-thaw cycles. The model shows that the total amount of defects due to freeze-thaw damage is related to the initial defects and the defect development capacity within the concrete. Based on the new freeze-thaw damage model, an equation for the loss of relative dynamic elastic modulus of concrete during freeze-thaw cycles was established using the relative dynamic elastic modulus of concrete as the defect indicator. In order to validate the damage model using relative dynamic elastic modulus as the defect index, freeze-thaw cycle tests of four kinds of concrete with different air content were carried out, and the rationality of the model was verified by the relative dynamic elastic modulus of concrete measured under different freeze-thaw cycling periods. On this basis, a freeze-thaw damage model of concrete was established considering the effect of air content in concrete. In addition, the model proposed in this paper was supplemented and validated by experimental data from other researchers. The results show that the prediction model proposed in this study is not only easy to apply and has clear physical meaning but also has high accuracy and general applicability, which provides support for predicting the degree of freeze-thaw damage of concrete structures in cold regions.
冻融破坏是影响寒冷地区混凝土耐久性的最重要因素之一，如何定量表征冻融循环对混凝土损伤程度的影响是研究人员广泛关注的问题。基于水压理论，通过假定混凝土在冻融循环过程中的缺陷发展模式，提出了一种新的混凝土冻融损伤模型。该模型表明，冻融损伤引起的缺陷总量与混凝土内部的初始缺陷和缺陷发展能力有关。基于新的冻融损伤模型，以混凝土相对动弹模量为缺陷指标，建立了混凝土在冻融循环过程中相对动弹模量损失的方程。为了验证以相对动弹模量为缺陷指标的损伤模型，对四种含气量不同的混凝土进行了冻融循环试验，并通过不同冻融循环次数下测得的混凝土相对动弹模量验证了模型的合理性。在此基础上，建立了考虑混凝土含气量影响的混凝土冻融损伤模型。此外，本文提出的模型还得到了其他研究人员实验数据的补充和验证。结果表明，本研究提出的预测模型不仅易于应用，物理意义明确，而且具有较高的精度和普遍适用性，为预测寒冷地区混凝土结构的冻融损伤程度提供了支持。
