微裂纹类型对结解侵蚀下的砂岩宏观裂纹的影响
Yanan Sun1, Bing Liang1, Junzu Ma1
1School of Mechanics and Engineering, Liaoning Technical University, Fuxin, China.
PloS one
|August 18, 2025
概括
冷解侵蚀通过产生微裂损坏了砂岩,削弱了它的强度并改变了裂纹模式. 这项研究揭示了微裂纹如何在重复的冷解周期下影响宏观骨折行为.
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
- 寒冷地区工程 寒冷地区工程
背景情况:
- 结冰解侵蚀在寒冷地区是一个重要的危险,导致岩石质量中的微裂.
- 不同的微裂变形式在融条件下对砂岩宏裂变的影响尚不清楚.
研究的目的:
- 分析微裂变对经过冷解循环的砂岩的宏裂变特征的影响.
- 阐明微裂变影响宏观骨折的机制.
主要方法:
- 采用了组合的声辐射 (AE) 测试和数值模拟.
- 分析包括峰值强度,弹性模量,纵向波速,AE声计数,b值,RA (道能量/总能量) 和AF (上升时间/频率含量).
- 一个数值模型的砂岩后融侵蚀被开发.
主要成果:
- 砂岩的峰值强度,弹性模量和波速随着结解周期的增加而减少.
- 在80个循环后,AE响声计数显示持续积累,表明渐进的微裂纹.
- b值趋势表明微裂变的持续积累.
- RA和AF值表明从剪切转向拉伸性故障模式,并增加结解周期.
- 数字模拟揭示了不均的移位和力链场,导致不同的断裂延伸模式.
结论:
- 融侵蚀逐渐削弱了砂岩,改变了其故障机制.
- 微裂纹,无论是沿晶体还是通过晶体,都显著影响了砂岩中的宏观裂纹模式.
- 了解这些微机制对于冷区工程和岩石质量的稳定性评估至关重要.
更多相关视频
10:36Stress Distribution During Cold Compression of Rocks and Mineral Aggregates Using Synchrotron-based X-Ray Diffraction
Published on: May 20, 2018
9.8K
09:00Visualization of Failure and the Associated Grain-Scale Mechanical Behavior of Granular Soils under Shear using Synchrotron X-Ray Micro-Tomography
Published on: September 29, 2019
13.5K
相关概念视频
01:20Microcracking in Concrete
208
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...
208
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
01:28Types of Non-structural Cracks in Concrete
244
Non-structural cracks are primarily of three types: plastic, early-age thermal, and drying shrinkage cracks. Plastic cracks are further classified into plastic shrinkage cracks and plastic settlement cracks.
Plastic shrinkage cracks typically form within hours after the concrete is poured. The concrete's surface dries faster than the bottom, creating tensile stress that the still-plastic concrete cannot withstand, leading to diagonal or randomly patterned cracks on the concrete surface.
Plastic shrinkage cracks typically form within hours after the concrete is poured. The concrete's surface dries faster than the bottom, creating tensile stress that the still-plastic concrete cannot withstand, leading to diagonal or randomly patterned cracks on the concrete surface.
244
01:26Unsoundness of Aggregate due to Volume Change
174
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...
174
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
01:28Effects of Air-entrainment in Concrete
140
Air entrainment in concrete significantly enhances the material's durability, especially in environments subjected to freeze-thaw cycles. Introducing small air bubbles into the concrete mix acts as internal voids that accommodate the expansion of water when it freezes, thereby alleviating internal stress and preventing structural cracks. This function is crucial in climates with significant freezing and thawing, as it protects the concrete from repeated stresses that could lead to premature...
140