在对混凝土火灾分裂-被动约束效应的选试验中确定应变和应力场
Katarzyna Mróz1, Izabela Hager1, Marcin Tekieli2
1Chair of Building Materials Engineering, Faculty of Civil Engineering, Cracow University of Technology, 24 Warszawska St., 31-155 Cracow, Poland.
Materials (Basel, Switzerland)
|January 8, 2025
概括
被动制显著恶化了火灾引起的混凝土裂变. 通过更宽的"冷轮"模拟的增加的热限制,导致更高的压力和更严重的裂变,突出了在消防安全评估中管理限制的必要性.
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
- 消防安全工程 消防安全工程
背景情况:
- 火灾引起的裂变是混凝土结构中关键的故障机制.
- 了解边界条件对裂变的影响对于结构性火灾设计至关重要.
- 之前的研究还没有完全量化热抑制对分裂严重性的影响.
研究的目的:
- 调查被动束对混凝土火灾造成的裂变的影响.
- 量化热抑制,应力演变和裂变深度之间的关系.
- 为了评估不同的"冷边缘"宽度在模拟束时的有效性.
主要方法:
- 使用一致的混凝土混合物以最大限度地减少变化.
- 准备好了各种尺寸的混凝土板块,用于火灾分裂试验.
- 应用ISO 834-1火线曲线,使用具有受控"冷边缘"边界条件 (0厘米,10厘米,20厘米) 的龙炉.
- 采用数字图像相关性 (DIC) 来监测表面应变场.
主要成果:
- 增加冷边框宽度导致混凝土中心区域的压力和应变更高.
- 没有限制的板块 (0厘米冷边缘) 显示最小的裂变.
- 被限制的板块 (20厘米的冷边缘) 呈现出明显增加的裂变深度和体积.
- 在压力,应变和裂变深度之间建立了定量相关性.
结论:
- 消极的热制约加剧了火灾引起的混凝土裂变.
- 束的程度直接影响裂纹的严重程度.
- 管理热限制对于准确的材料选和结构性消防安全评估至关重要.
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