在冷解周期后,H型钢和混凝土之间的结合行为
Yongjun Lin1, Sihua Jiang2, Shuiyun Zhong2
1School of Civil Engineering, Southwest Jiaotong University, Chengdu, 610031, China. scsmith@126.com.
Scientific reports
|August 11, 2025
概括
冷解周期降低了H型钢和混凝土之间的结合强度,而更高的杆比率提高了性能. 本研究分析了寒冷气候中复合结构的故障模式和键强度降低.
科学领域:
- 土木工程 土木工程是指土木工程.
- 材料科学 材料科学 材料科学
- 结构工程 结构工程
背景情况:
- 复合结构越来越多地用于建筑.
- 了解钢混凝土纽带在环境压力因素 (如冷解周期) 下的耐用性,对于结构完整性至关重要.
- 结解 (F-T) 对混凝土中嵌入的H形钢的结合性能的影响需要详细的研究.
研究的目的:
- 为了研究H形钢和混凝土在各种冷解周期下的结合行为.
- 分析杆比率和F-T周期对结合强度,故障模式和结合应力滑动曲线的影响.
- 开发一个回归模型来预测债券强度退化.
主要方法:
- 推出测试是在0,25和50个冷解周期下的H形钢混凝土样本 (C35) 上进行的.
- 测试了0.4%,0.8%和1.2%的体积计杆比率,固定长度为380毫米和560毫米.
- 分析了实验数据,以确定故障模式,结合强度和结合应力滑动特性.
主要成果:
- 故障模式从分割/拉出转移到推出故障,随着FT周期的增加.
- 结合强度在50次F-T循环后下降,固定长度减少到82.2% (380毫米) 和84.7% (560毫米).
- 在F-T条件下,较高的杆比率 (1.2%与0.4%) 导致更大的拉出力和键强度.
- 债券应力滑动曲线显示,峰值应力降低,峰值负载滑动增加,具有更多的FT周期.
结论:
- 冷解周期显著降低了H型钢和混凝土之间的结合性能.
- 螺纹增强在增强结合强度和抵抗F-T诱导损伤方面发挥着至关重要的作用.
- 开发的回归模型有助于预测长期性能和评估复合结构在寒冷环境中的耐用性.
相关概念视频
01:27Corrosion of Reinforcement
253
The corrosion of steel reinforcement within concrete is a process influenced by the material's inherent properties and external factors. The high pH level of around 13, provided by calcium hydroxide present in concrete, initially protects the steel reinforcement by promoting the formation of a passive iron oxide layer on its surface.
However, over time and under certain conditions like carbonation, chloride ingress, and cracking this protective state can be compromised. Steel has areas with...
However, over time and under certain conditions like carbonation, chloride ingress, and cracking this protective state can be compromised. Steel has areas with...
253
01:27Frost Action on Concrete
151
Concrete structures in cold climates, such as those along roadsides, can retain moisture. This moisture makes them susceptible to frost-related damage when temperatures fall below freezing. Adding moisture worsens the damage during temperature fluctuations, leading to repeated freezing and thawing. De-icing salts, spread over these structures to melt ice, add to the freeze-thaw cycle, and draw even more moisture into the concrete.
This freeze-thaw cycle primarily causes surface scaling, where...
This freeze-thaw cycle primarily causes surface scaling, where...
151
01:29Frost Resistant Concrete
135
Concrete's susceptibility to frost damage during freeze-thaw cycles demands strategic measures to enhance its frost resistance. Employing techniques like air entrainment, adjusting the water-cement ratio, proper curing, and selecting appropriate aggregates are essential.
Introducing microscopic air bubbles into the concrete mix through air entrainment creates small voids that accommodate ice expansion, thereby reducing internal pressures and preventing cracking. The optimal amount of...
Introducing microscopic air bubbles into the concrete mix through air entrainment creates small voids that accommodate ice expansion, thereby reducing internal pressures and preventing cracking. The optimal amount of...
135
01:27Cold Weather Concreting
112
When freshly poured concrete is exposed to freezing temperatures before it has set, the water within the concrete can freeze. This expansion disrupts the setting process, delays chemical reactions necessary for hardening, and increases the volume of pores within the hardened concrete, which weakens its overall structure. If the concrete manages to reach an appreciable strength before it freezes, the damage can be somewhat mitigated.
To counteract the negative impacts of cold weather, ensuring...
To counteract the negative impacts of cold weather, ensuring...
112
01:22Effect of Sea Water on Concrete
449
Concrete exposed to seawater can undergo degradation like the dissolution of ettringite and gypsum, increasing the material's porosity and decreasing its strength. In contrast, the crystallization of salts within the concrete's pores can cause expansion, particularly above the waterline where evaporation occurs. Nonetheless, this expansion only happens when seawater, enabled by the concrete's permeability, manages to infiltrate the structure.
Concrete in areas between tide marks,...
Concrete in areas between tide marks,...
449
01:23Behavior of Concrete Under Compressive Load
273
Concrete exhibits specific behaviors under different compressive loads. Understanding this is crucial for understanding its structural integrity. When concrete undergoes uniaxial compression, it tends to develop cracks that run parallel to the direction of the force. These parallel cracks stem from localized tensile stresses that occur perpendicular to the compression direction. Additionally, angled cracks may appear due to the formation of shear planes.
As the concrete specimen fractures under...
As the concrete specimen fractures under...
273