在高温后对碎混凝土机械性能进行实验研究
Yang Han1,2, Zhishuan Lv1, Yaqiang Bai3
1College of Civil Engineering, Kashi University, Kashi 844008, China.
Polymers
|July 29, 2023
概括
粉碎混凝土 (CRC) 显示,随着更高的含量和升高的温度,裂纹和质量损失增加. 强度和弹性模量等机械性能下降,表明CRC对性比强度应用更好.
科学领域:
- 材料科学 材料科学 材料科学
- 土木工程 土木工程是指土木工程.
- 环境工程 环境工程
背景情况:
- 废给环境带来了挑战.
- 粉碎混凝土 (CRC) 通过使用回收来提供可持续的解决方案.
- 了解CRC在压力和热量下的行为对于其应用至关重要.
研究的目的:
- 在高温下研究CRC的机械性能,其中含有不同的碎含量.
- 评估温度和含量对CRC质量损失,强度和应力-应变行为的影响.
- 确定CRC适用于优先考虑性而不是高强度的应用的适用性.
主要方法:
- 准备了含有0%,10%和20%粉碎的CRC标本.
- 标本被暴露在高温 (300°C,500°C,700°C) 中.
- 评估了质量损失,热导率,压力强度,分裂拉伸强度,轴向压力强度,弹性模量和应力-延展特性.
主要成果:
- 增加的碎含量和温度导致了更广泛的表面裂和更大的质量损失.
- 立方体压力强度,分裂拉力强度,轴向压力强度和弹性模量随着含量和温度的提高而下降.
- 高温对拉伸强度的分裂影响最大,其次是弹性模量,轴向压力强度和立方压力强度.
- 应力-应变曲线在更高的温度下变平,峰值应力降低,峰值应变增加;较高的含量降低了峰值应力,但对峰值应变影响最小.
结论:
- 在高温下,CRC的机械强度和刚度降低,性能降解随着含量和暴露于热量而增加.
- 该研究强调,CRC的增强的塑料故障特性和性使其适合于抗冲击和灵活性优先于最大承载能力的应用.
- 对于特定的建筑应用,CRC是一个可行的环保替代方案,特别是那些受益于提高性和能量吸收的建筑应用.
更多相关视频
10:52Conducting Elevated Temperature Normal and Combined Pressure-Shear Plate Impact Experiments Via a Breech-end Sabot Heater System
Published on: August 7, 2018
8.6K
11:17Synthesis of Programmable Main-chain Liquid-crystalline Elastomers Using a Two-stage Thiol-acrylate Reaction
Published on: January 19, 2016
21.8K
相关概念视频
01:20Hot Weather Concreting
91
Concreting at elevated temperatures accelerates the hydration process, leading to quicker setting but potentially reducing the long-term strength of the concrete structure. Additionally, low air humidity fosters rapid moisture loss from the concrete, resulting in reduced workability, pronounced plastic shrinkage, and a higher likelihood of crazing.
Mitigating the heat increase in concrete can be economically achieved by shading aggregate stockpiles to prevent heating from solar radiation,...
Mitigating the heat increase in concrete can be economically achieved by shading aggregate stockpiles to prevent heating from solar radiation,...
91
01:22Mass Concreting
90
Mass concreting refers to the process of placing large volumes of concrete, such as in gravity dams. The heat generated during the cement hydration process and differential cooling rates within the concrete mass can lead to a temperature gradient, which can result in thermal cracks in the concrete mass.
To reduce the risk of such cracking, the concrete mix may incorporate low-heat cement and pozzolans to reduce the temperature rise. Pre-cooled angular aggregates and water-reducing admixtures...
To reduce the risk of such cracking, the concrete mix may incorporate low-heat cement and pozzolans to reduce the temperature rise. Pre-cooled angular aggregates and water-reducing admixtures...
90
01:20Microcracking in Concrete
149
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...
149
01:27Cold Weather Concreting
92
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...
92
01:14Design Example: Managing Concrete Workability
101
This example deals with managing the workability of concrete for a raft foundation project under hot weather conditions. Workability is crucial for ensuring the concrete is easy to place, compact, and finish. In this scenario, a slump test — a common method to measure the workability of fresh concrete — initially indicated low workability. This was attributed to the rapid water loss from the concrete mix, exacerbated by the high temperatures causing the course aggregates to heat up.
101
01:23Abrasion Resistance of Concrete
164
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...
164