试验性调查尺寸效应的滚筒压缩液压青混凝土在不同的应变率下负载的尺寸效应
Xiao Meng1, Yunhe Liu1, Zhiyuan Ning1
1State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an 710048, China.
Materials (Basel, Switzerland)
|January 23, 2024
概括
样本大小显著影响液压青混凝土 (HAC) 的性能. 较大的标本显示强度降低,但硬度增加,应变率加剧这些尺寸效应. 一项新的法律模拟了这种动态行为.
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
- 地质技术工程 地质技术工程
背景情况:
- 在寒冷的阿尔卑斯山地区,青混凝土对于不透的液压结构至关重要.
- 动态机械性能对应变速率和样本大小都很敏感.
- 有限的研究存在于液压青混凝土 (HAC) 的尺寸效应在不同的负载率下.
研究的目的:
- 研究尺寸对滚筒压缩液压青混凝土 (RCHAC) 机械性能和故障模式的影响.
- 分析应变速率对这些尺寸效应的影响.
- 为RCHAC提出和验证一个修改的动态尺寸效应定律.
主要方法:
- 准备四种尺寸的RCHAC标本 (50mm,100mm,150mm,200mm高度). 在四个尺寸 (50mm,100mm,150mm,200mm高度).
- 在5°C的不同负载率下 (10−5−1~10−2−1) 测试试样.
- 评估压力强度,弹性模量和故障模式.
主要成果:
- 样本大小的增加降低了压力强度和失效程度,同时增加了弹性模量.
- 压力强度随着高度从50mm增加到200mm,下降了50%以上.
- 弹性模量随着尺寸的增加而显著增加,而延展率加剧了这些趋势.
结论:
- 标本大小和应变率是影响RCHAC机械行为的关键因素.
- 一个修改的动态尺寸效应定律有效地描述了观察到的现象.
- 这些发现对于在寒冷气候下设计耐用的液压青混凝土结构至关重要.
相关概念视频
01:23Abrasion Resistance of Concrete
134
Abrasion resistance is an essential characteristic of concrete that determines its durability and longevity under various wear conditions. Concrete surfaces are vulnerable to different types of abrasion. For instance, surfaces may wear down due to the constant movement of vehicles or be eroded by solids carried in water, as seen in concrete canal linings. Specific tests are conducted to measure the abrasion resistance of concrete.
One such test is the revolving disc test, where three plates...
One such test is the revolving disc test, where three plates...
134
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
01:22Creep in Concrete
239
Creep refers to the time-dependent increase in strain under a sustained load, excluding other time-dependent deformations associated with shrinkage, swelling, and thermal expansion in concrete. The primary mechanism behind creep involves the loss of physically adsorbed water from the calcium silicate hydrate within the hydrated cement paste. This process is further exacerbated by concrete's non-linear stress-strain relationship, microcrack development in the interfacial transition zone, and...
239
01:22Fatigue Strength of Concrete
192
Fatigue, in the context of materials science and engineering, refers to the weakening or failure of a material caused by repeatedly applied loads, even if these loads are below the strength limit of the material. Fatigue strength in concrete is a critical property that influences its durability and longevity. Concrete can fail in two ways due to fatigue. Static fatigue or creep rupture occurs under a constant load or one that increases slowly. The other failure mode is due to cyclical or...
192
01:22Compacting Factor test
160
The compacting factor test is a method used to assess the workability of concrete. It is especially suitable for concrete mixes containing aggregates up to one and a half inches in size. This test involves specialized equipment consisting of two truncated cone-shaped hoppers and a cylinder, all with polished interior surfaces to minimize friction.
The procedure begins by placing concrete into the upper hopper without any compaction. Once filled, the bottom door of this hopper is opened,...
The procedure begins by placing concrete into the upper hopper without any compaction. Once filled, the bottom door of this hopper is opened,...
160
01:22Toughness and Hardness of Aggregate
262
Toughness and hardness are critical properties of aggregate materials used in concrete, particularly on pavement surfaces and industrial flooring subjected to heavy loads. Toughness is defined as the aggregate's resistance to failure by impact and is measured by the aggregate impact value (AIV). For this, the aggregate impact value test is performed, wherein the impact is delivered by a standard hammer, which falls freely under its own weight onto the aggregates. The aggregates fragment in...
262