...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Fire and materials >Effect of cooling methods on residual compressive strength and cracking behavior of fly ash concretes exposed at elevated temperatures
【24h】

Effect of cooling methods on residual compressive strength and cracking behavior of fly ash concretes exposed at elevated temperatures

机译：冷却方法对高温下暴露的粉煤灰混凝土残余抗压强度和开裂行为的影响

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

This paper presents the effects of cooling methods on residual compressive strength and cracking behavior of concretes containing four different class F fly ash contents of 10%, 20%, 30% and 40% as partial replacement of cement at various elevated temperatures. The residual compressive strength of the aforementioned fly ash concretes is measured after being exposed to 200, 400, 600 and 800 degrees C temperatures and two different cooling methods, for example, slow cooling and rapid water cooling. Results show that the residual compressive strengths of all fly ash concretes decrease with increase in temperatures irrespective of cooling regimes, which is similar to that of ordinary concrete. Generally, control ordinary concrete and all fly ash concretes exhibited between 10% and 35% more reduction in residual compressive strength because of rapid cooling than slow cooling except few cases. Cracks are observed over concrete specimens after being exposed to temperatures ranging from 400 to 800 degrees C. Samples that are slowly cooled developed smaller cracks than those rapidly cooled. At 800 degrees C, all fly ash concretes that are exposed to rapid cooling showed the most severe cracking. X-ray diffraction analysis shows reduction of Ca(OH)(2) peak and formation of new calcium silicate peak in concretes containing 20% and 40% fly ash when subjected to 800 degrees C in both cooling methods. Thermo gravimetric analysis and differential thermal analysis results show increase in thermal stability of concrete with increase in fly ash contents. The existing Eurocode also predicted the compressive strength of fly ash concretes with reasonable accuracy when subjected to the aforementioned elevated temperatures and cooling methods. Copyright (c) 2014 John Wiley & Sons, Ltd.
机译：本文介绍了冷却方法对四种不同F级粉煤灰含量分别为10％，20％，30％和40％的混凝土的残余抗压强度和开裂行为的影响，这些粉煤灰是在各种高温下部分替代水泥的方法。在暴露于200、400、600和800摄氏度的温度和两种不同的冷却方法（例如缓慢冷却和快速水冷）后，测量上述粉煤灰混凝土的残余抗压强度。结果表明，与冷却方式无关，所有粉煤灰混凝土的残余抗压强度均随温度的升高而降低，这与普通混凝土相似。通常，与普通冷却混凝土和所有粉煤灰混凝土相比，除少数情况外，由于快速冷却比缓慢冷却，残余抗压强度降低幅度在10％至35％之间。暴露于400至800摄氏度的温度后，在混凝土试样上观察到裂缝。与缓慢冷却的试样相比，缓慢冷却的试样产生的裂缝较小。在800摄氏度下，所有经受快速冷却的粉煤灰混凝土均显示出最严重的开裂。 X射线衍射分析显示，两种冷却方法均在800摄氏度下对粉煤灰含量为20％和40％的混凝土进行还原，从而降低了Ca（OH）（2）峰并形成了新的硅酸钙峰。热重分析和差热分析结果表明，混凝土的热稳定性随粉煤灰含量的增加而增加。现有的欧洲规范还预测了在经受上述高温和冷却方法后，粉煤灰混凝土的抗压强度具有合理的准确性。版权所有（c）2014 John Wiley＆Sons，Ltd.

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号