在结解作用下和砂岩的机械性能和损害构成模型
Meimei Feng1,2, Xiaoxiao Cao3, Taifeng Wu2
1State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering, China University of Mining and Technology, Xuzhou 221116, China.
Materials (Basel, Switzerland)
|December 17, 2024
概括
冷解周期会损害砂岩,降低其强度和弹性模量,特别是在-5°C至-10°C的温度下. 孔隙结构发生显著的变化,在应力和孔隙压力下影响机械性能.
科学领域:
- 地质技术工程 地质技术工程
- 材料科学 材料科学 材料科学
- 岩石机械学 岩石机械学
背景情况:
- 结冰解周期是影响岩石质量的稳定性的重要环境因素.
- 了解地面应力,孔隙水压和冷解损伤的结合效应对于工程应用至关重要.
研究的目的:
- 为了研究融损害对合应力和孔隙水压下砂岩机械性能的影响.
- 分析结和解后砂岩孔状结构的演变.
- 开发和验证冰解损坏的砂岩的统计损害构成模型.
主要方法:
- 在 -5°C, -10°C, -15°C和 -20°C下对三种多孔砂岩进行结.
- 在冰解的砂岩上进行液压合三轴压缩试验.
- 执行核磁共振测试,以分析孔隙结构的演变.
主要成果:
- 峰值偏差应力和弹性模量随着结温度的降低而下降,在-5°C和-10°C之间有显著下降.
- 在冷解后,核磁孔隙性增加,而较低孔隙性样本的变化率更高.
- 一个包含压缩系数K的统计损害构成模型准确地反映了实验数据.
结论:
- 冷解损伤显著改变了砂岩的机械行为和孔隙结构.
- 开发的构成模型有效地描述了沙岩在复杂的压力和环境条件下.
- 这些发现为在寒冷地区的钻井设计和维护提供了基础.
更多相关视频
相关概念视频
Frost Action on Concrete
92
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...
92
Unsoundness of Aggregate due to Volume Change
97
Unsoundness in aggregates due to volume changes is primarily caused by the physical alterations aggregates undergo, such as freezing and thawing, thermal changes, and wetting and drying. Unsound aggregates, when subjected to these changes, result in volume change upon disintegration. This, in turn, contributes to the deterioration of concrete, including scaling, pop-outs, and cracking. Particular types of aggregates, such as porous flints, cherts, and those containing clay minerals, are...
97
Frost Resistant Concrete
74
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...
74
Stress-Strain Diagram - Brittle Materials
2.2K
Brittle materials, including glass, cast iron, and stone, exhibit unique characteristics. They fracture without considerable change in their elongation rate, indicating that their breaking and ultimate strength are equivalent. Such materials also show lower strain levels at the point of rupture. The failure in brittle materials predominantly results from normal stresses, as evidenced by the rupture created along a surface perpendicular to the applied load. These materials do not display...
2.2K
Brick Durability, Strength, and Appearance
146
Brick durability, strength, and appearance are crucial factors in construction, influencing the choice of bricks for specific applications. The process of freeze-thaw, for instance, significantly affects brick durability. This phenomenon occurs when water absorbed by a brick expands as it freezes, potentially causing damage when it melts and refreezes. Bricks are graded for durability: SW-grade bricks are the most durable, offering high strength and low water absorption, followed by MW-grade...
146
Microcracking in Concrete
100
Microcracking in concrete refers to the tiny cracks that can form within the material even before any external load is applied. These microcracks typically occur at the interface between the coarse aggregate and the hydrated cement paste, often as a result of differential volume changes prompted by variations in stress-strain behavior, as well as thermal and moisture movement. Initially, these microcracks remain stable and do not grow substantially until the concrete is stressed to about 30...
100


