在不同的煤炭下混凝土降解的微观结构机制 河沙子替代比率
Yukai Cai1, Wenhua Zha1, Tao Xu1
1School of Civil and Architectural Engineering, East China University of Technology, Nanchang 330013, China.
Materials (Basel, Switzerland)
|October 29, 2025
概括
使用煤制造砂 (CGS) 作为天然砂的替代品会影响混凝土的性能. 较高的CGS含量降低了界面过渡区,导致脆性行为和机械强度降低.
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.
- 地质技术工程 地质技术工程
背景情况:
- 煤制砂 (CGS) 是建筑材料中天然砂的可持续替代品.
- 混凝土性能恶化的微观机制与不同的CGS替代水平尚未完全理解.
- 了解这些机制对于优化CGS利用和确保结构完整性至关重要.
研究的目的:
- 研究不同CGS替代水平的混凝土中机械性能恶化的微机制.
- 建立一个合能源,力链和裂传播的框架.
- 评估CGS对界面过渡区 (ITZ) 和故障模式的影响.
主要方法:
- 混凝土立方样本的单轴压缩试验具有0%,25%,50%,75%,100%的CGS替换.
- 粒子流代码2D (PFC2D) 离散元件模拟以模拟裂的启动和传播.
- 扫描电子显微镜 (SEM) 用于观察ITZ中的微观结构变化.
主要成果:
- 实验和模拟结果显示,在峰值应力,应变和曲线形状方面,一致性很好 (误差<5%).
- 增加CGS含量降解了ITZ,增加了孔隙/微裂,裂类型从粘合剂转变为凝聚剂,并局部化了力链.
- 更高的CGS替代导致峰值应变能量的降低,摩擦消散的增加,以及从柔性转变为脆性的故障.
结论:
- 低CGS替换率 (25-50%) 促进了稳定的负载转移,并抑制了裂.
- 高CGS替换率 (75-100%) 导致ITZ退化和力链不稳定,导致集中裂纹和机械性能降低.
- 开发的能量-力-链裂框架有效地解释了随着CGS含量增加的宏观性能变化.
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