高温冷却后超高性能混凝土残余力学性能研究
CSTR:
作者:
作者单位:

作者简介:

通讯作者:

中图分类号:

基金项目:

国家自然科学基金资助项目(52278172);河南省粮油仓储建筑与安全重点实验室开放课题(2020KF-B06);河南省教育厅自然科学基金项目(24A560006)


Study on the residual mechanical properties of UHPC after high temperature with different cooling methods
Author:
Affiliation:

Fund Project:

  • 摘要
  • |
  • 图/表
  • |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • |
  • 资源附件
  • |
  • 文章评论
    摘要:

    为研究不同冷却方式对高温后超高性能混凝土(UHPC)单轴受压力学性能的影响,以冷却方式、受热温度为变化参数,设计制作了45个100 mm×100 mm×300 mm的试块进行高温后的单轴抗压试验。通过观察高温后试块的表观特征、质量损失及破坏形态,分析了冷却方式及受热温度对抗压强度的影响规律。结果表明:随着受热温度升高,试块表面裂纹增多,不同冷却方式下的质量烧失率均增大;相同温度下,自然冷却时试块烧失率大于浸水冷却烧失率,自然冷却下烧失率呈先快后慢的增长趋势,浸水冷却下烧失率近似呈线性增长;抗压强度均呈现先小幅增大后减小的趋势,与常温工况相比,自然冷却、浸水冷却时最大抗压强度分别提高了18.3%和13.4%;受热温度为800 ℃时,自然冷却、浸水冷却抗压强度分别降低至常温下的20.8%和18.8%;受热温度超过600 ℃时,试块表现出较好的轴向变形能力;相较于自然冷却,浸水冷却下峰值应变发展较快,但800 ℃时基本趋于一致,自然冷却、浸水冷却下峰值应变分别增大至常温工况下峰值应变的2.22倍、2.24倍;与自然冷却相比,浸水冷却下弹性模量相对较小,且均经历慢降、快降、慢降3个阶段。基于试验,提出了浸水冷却后的UHPC残余强度计算方法,该方法可为建筑消防灭火后混凝土承载能力评估提供依据。

    Abstract:

    To investigate the effect of different cooling methods on the uniaxial compressive properties of ultra-high performance concrete (UHPC) after high temperature, 45 specimens with the dimension of 100 mm×100 mm×300 mm were designed and fabricated.The cooling methods and heating temperature were chosen as test variable parameters.Observe the apparent characteristics, quality loss, and failure mode were observed after different high temperatures and cooling methods.The variation law of compressive strength was analyzed.The experimental results show that as the temperature increases, the surface cracks increase.The mass loss rate increases under different cooling methods.A higher mass loss rate occurs under natural cooling with the same temperature.Under natural cooling, the mass loss rate increases rapidly at first and then slowly.An approximately linear increase is presented under water cooling.The compressive strength shows a trend of first slightly increasing and then decreasing.Compared with the normal temperature, with the temperature increase, the maximum compressive strength increased by 18.3% and 13.4% respectively under natural cooling and water cooling.When the temperature reaches 800 ℃, the compressive strength under natural cooling and water cooling decreases to 20.8% and 18.8% of compressive strength at normal temperature, respectively.When the temperature exceeds 600 ℃, the axial deformation ability of blocks is significantly enhanced.Compared with natural cooling, the peak strain under water cooling develops rapidly, but tends to be consistent at 800 ℃.The peak strain under natural cooling and water cooling increases to 2.22 times and 2.24 times the peak strain under normal temperature conditions, respectively.Compared with natural cooling, the elastic modulus under water cooling is relatively small and undergoes three stages: slow decrease, fast decrease, and slow decrease.Based on the experiments, a formula for calculating the residual strength of UHPC after water cooling is proposed, which can provide a basis for evaluating the load-bearing capacity of a building after fire.

    参考文献
    相似文献
    引证文献
引用本文

周超锋*,朱重澳,庞瑞,薛建阳,李亚东.高温冷却后超高性能混凝土残余力学性能研究[J].实验力学,2025,40(4):528~538

复制
分享
相关视频

文章指标
  • 点击次数:
  • 下载次数:
  • HTML阅读次数:
  • 引用次数:
历史
  • 收稿日期:2024-04-11
  • 最后修改日期:2024-07-15
  • 录用日期:
  • 在线发布日期: 2025-09-29
  • 出版日期:
文章二维码