Compressive Strength Study and Microscopic Analysis of Multi-aged Existing Concrete After High Temperature(PDF)
《建筑科学与工程学报》[ISSN:1673-2049/CN:61-1442/TU]
- Issue:
- 2014年04期
- Page:
- 45-50
- Research Field:
- Publishing date:
Info
- Title:
- Compressive Strength Study and Microscopic Analysis of Multi-aged Existing Concrete After High Temperature
- Author(s):
- BAI Liang; ZHOU Tian-hua; LU Jing; ZHANG Yi; LUO Wei
- School of Civil Engineering, Chang’an University
- Keywords:
- high temperature; existing concrete; residual compressive strength; weight loss ratio; microscopic analysis; age
- PACS:
- -
- DOI:
- -
- Abstract:
- In order to study the damage and microscopic variation characteristics of multi-aged existing concrete after high temperature, the experiment study on the existing concrete after high temperature was conducted by drill concrete specimens in reinforced concrete (RC) structures with more than twenty years age. Based on the experiments, the variation regularities of residual compressive strength of existing concrete after high temperature were proposed and the empirical regression formula was established between residual compressive strength of existing concrete and different temperatures. By using thermogravimetry and stereo scan test, the lithofacies and microstructure of existing concrete after high temperature were analyzed. The study results show that the change of residual compressive strength of existing concrete under different temperatures is similar to the change of fresh placing concrete in laboratory. While the temperature T≤300 ℃, the residual compressive strength of existing concrete is relative low; while the temperature T＞700 ℃, the values are higher. The obtained results can provide a referenced basis for appraisement of multi-aged existing concrete structure after high temperature.
Last Update: 2014-12-18