| 摘要: |
| 对不同冻融损伤程度的混凝土圆环体试件进行了试验研究.结果表明：当相对冻融深度小于临界值时，混凝土的峰值应力、峰值应变均呈线性退化，超过临界值后则保持稳定；当冻融循环次数由100次增加到200次时，相对冻融深度临界值由0.5增大到0.8；基于应变等价性假说和统计损伤理论，建立了不同冻融损伤程度下承压混凝土的应力-应变关系模型. |
| 关键词: 冻融损伤 承压混凝土 本构关系 损伤梯度 |
| DOI：10.3969/j.issn.1007-9629.2023.10.002 |
| 分类号:TU528.1 |
| 基金项目:国家自然科学基金资助项目（52178163；51808437）；陕西省重点研发计划项目（2022SF-403） |
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| Effect of Frozen Damage Gradient on Stress-Strain Relationship of Stressed Concrete |
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LIU Xiguang1, LEI Yongjie1, ZHOU Jiali2, NIU Ditao1, LIU Jun1
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1.College of Civil Engineering， Xi’an University of Architecture and Technology， Xi’an 710055， China;2.XAUAT Engineering Technology Co.， Ltd.， Xi’an 710055， China
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| Abstract: |
| Experimental research was conducted on concrete torus-shaped specimens with different degrees of freeze-thaw damage. The results show that when the relative freeze-thaw depth is less than the threshold， the peak stress and peak strain of concrete exhibit linear degradation， while remained stable after exceeding the threshold. When the number of freeze-thaw cycle increases from 100 times to 200 times， the threshold of relative freeze-thaw depth increases from 0.5 to 0.8. Finally， based on the hypothesis of strain equivalence and statistical damage theory， the stress-strain relationship model of stressed concrete with different degrees of freeze-thaw damage is established. |
| Key words: freeze-thaw damage stressed concrete constitutive relationship damage gradient |
