关于盐土壤不受限制的压力强度和变形特征的研究
1Institute of Geotechnical Engineering, Xi'an University of Technology, Xi'an, China.
Scientific reports
|January 17, 2024
概括
这项研究调查了盐和水含量如何影响盐土的强度和体积. 为人工结构土壤进行最佳的盐土制备,需要将3%的NaCl添加到Xi Xi中.
科学领域:
- 地质技术工程 地质技术工程
- 土壤科学 土壤科学
- 材料科学 材料科学 材料科学
背景情况:
- 盐土在中国很普遍,具有不同的区域特征.
- 了解盐水土壤的行为对于基础设施开发和土地管理至关重要.
研究的目的:
- 研究化 (NaCl) 含量和水含量对的强度和体积变化的影响.
- 用扫描电子显微镜分析这些变化的潜在机制.
- 为人工制备结构性土壤提供见解.
主要方法:
- 通过将不同度的NaCl添加到西安液中来配置盐土样本.
- 在广泛的含水量范围内进行实验.
- 使用扫描电子显微镜分析土壤微观结构.
主要成果:
- 土壤强度随着含水量下降而增加,湿度为12%的临界点.
- 在12%以上的含水量,土壤强度随着盐含量增加而降低.
- 在不到12%的含水量下,土壤强度按照以下顺序进行:3% NaCl > 1% NaCl > 5% NaCl > 0% NaCl.
- 体积变化受到弹性变形,水损失收缩和盐膨胀的影响.
- 含有3%和5%NaCl的样本显示,在15%含水量时,体积变化的拐点为15%.
- 3%的NaCl含量导致了高强度和最小的盐扩张,低于12%的含水量.
- 微观结构分析揭示了较小的孔隙和盐包裹的颗粒接触,盐含量更高.
结论:
- 这项研究提供了一种模拟土壤凝固的方法,使用3%的NaCl用于人工结构土壤的.
- 水含量显著影响盐土强度,其中12%作为关键值.
- 盐含量影响土壤强度和体积变化,在特定应用中确定了最佳条件.
更多相关视频
10:00Experimental Protocol to Determine the Chloride Threshold Value for Corrosion in Samples Taken from Reinforced Concrete Structures
Published on: August 31, 2017
15.4K
08:09Wastewater Irrigation Impacts on Soil Hydraulic Conductivity: Coupled Field Sampling and Laboratory Determination of Saturated Hydraulic Conductivity
Published on: August 19, 2018
9.2K
相关概念视频
01:23Behavior of Concrete Under Compressive Load
171
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...
171
01:22Effect of Sea Water on Concrete
237
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,...
237
01:14Testing Water Quality
111
When the quality of water for concrete preparation is uncertain, its impact on the setting time of cement and compressive strength of mortar is assessed by comparison with de-ionized or distilled water benchmarks. American Society for Testing and Materials (ASTM) C1602 requires the setting times to be within 90 minutes of the control, British Standard (BS) 3146:1980 allows a 30-minute variance in the initial setting, while British Standards European Norm (BS EN) 1008 specifies initial setting...
111
01:20Strength of Cement
138
Strength tests for cement are not performed directly on neat cement paste due to difficulty in obtaining consistent, reliable specimens. Instead, cement is typically tested in the form of cement-sand mortar.
For compressive strength tests, ASTM C 109-05 standards prescribe a cement-sand mix ratio of 1:2.75 and a water/cement ratio of 0.485 for making 2-inch cubes. These cubes are mixed, cast, and cured in saturated lime water at 23°C until testing. Flexural strength testing, outlined in...
For compressive strength tests, ASTM C 109-05 standards prescribe a cement-sand mix ratio of 1:2.75 and a water/cement ratio of 0.485 for making 2-inch cubes. These cubes are mixed, cast, and cured in saturated lime water at 23°C until testing. Flexural strength testing, outlined in...
138
01:25Deleterious Substances in Aggregate
168
Deleterious substances in aggregates can be detrimental to the quality and durability of concrete. These substances include organic impurities like loam, which interfere with cement hydration and are usually present in the sand. These prevent a good bond between aggregate and cement paste. Organic impurities can be detected using the colorimetric test, where the darkness of a solution after agitation indicates the level of organic content.
Another type of impurity is clay and fine material that...
Another type of impurity is clay and fine material that...
168
01:20Elasticity in Concrete
95
Upon subjecting concrete to moderate or high uniaxial compressive or tensile stresses, the strain response is non-linear relative to the stress applied. As the stress is removed, the resulting stress-strain curve deviates from the original path traced during loading, creating a hysteresis loop, indicative of the concrete's non-linear and non-elastic properties. Typically, a material's modulus of elasticity, which is a measure of the material's stiffness, is inferred from the linear...
95