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Vertical Push-down Tests of RC Beams at High Temperature Considering Axial Restraint(PDF)

《建筑科学与工程学报》[ISSN:1673-2049/CN:61-1442/TU]

Issue:
2020年01期
Page:
41-48
Research Field:
Publishing date:

Info

Title:
Vertical Push-down Tests of RC Beams at High Temperature Considering Axial Restraint
Author(s):
HUO Jing-si1; 2;  HAO Bai-qing1;  LI Zhi1
(1. Key Laboratory of Building Safety and Energy Efficiency of Ministry of Education, Hunan University, Changsha 410082, Hunan, China; 2. Fujian Provincial Key Laboratory of Intelligent Infrastructure and Monitoring, Huaqiao University, Xiamen 361021, Fujian, China; 3. LERA Consulting Structural Engineers, New York NY10005, USA)
Keywords:
reinforced concrete beam;  axial restraint;  high temperature;  large deformation;  failure mode
PACS:
TU375.1
DOI:
10.19815/j.jace.2018.11069
Abstract:
In order to investigate the influence of axial restraint on the mechanical behaviours of fire-exposed reinforced concrete(RC)beams at large deformation, the push-down tests of one restrained beam at ambient temperature and two restrained beams at high temperature were carried out. The effects of different heating time on the measuring point temperature, heating response, ductility and energy dissipation of axially restrained RC beams were compared and analyzed. The thermal response, failure mode, bearing capacity and force mechanism of axially restrained RC beams were mainly studied. The results show that during the heating process, with the increase of temperature, the axially restrained RC beams deflect downward continuously, but the deflection recovers after the furnace temperature exceeds 800 ℃. Due to the influence of axial compression caused by thermal expansion, the plastic hinge area of restrained beams at high temperature is obviously reduced, and its ductility and energy dissipation capacity decrease with the increase of temperature. The initial axial compression caused by high temperature increases the peak bearing capacity of beams, but with the increase of heating time, the increase amplitude is less than the decrease amplitude of peak bearing capacity of beams caused by material deterioration. The initial axial compression makes high temperature beams always in bending mechanism before failure. The paper can provide reliable experimental data for verifying and modifying the numerical simulation as well as theoretical analysis of the mechanical behavior of confined concrete beams under fire, and provide a basis for further exploring the failure criteria of axially restrained RC beams under large deformation at high temperature.

References:

[1] 过镇海,时旭东.钢筋混凝土的高温性能及其计算[M].北京:清华大学出版社,2003.
GUO Zhen-hai,SHI Xu-dong.Behavior of Reinforced Concrete at Elevated Temperature and Its Calculation[M].Beijing:Tsinghua University Press,2003.
[2]陆洲导,朱伯龙,周跃华.钢筋混凝土简支梁对火灾反应的试验研究[J].土木工程学报,1993,26(3):47-54.
LU Zhou-dao,ZHU Bo-long,ZHOU Yue-hua.Experimental Study on Fire Response of Simple Supported Reinforced Concrete Beams[J].China Civil Engineering Journal,1993,26(3):47-54.
[3]时旭东,过镇海.高温下钢筋砼连续梁的破坏机构和内力重分布研究[J].建筑结构,1996,26(7):34-37.
SHI Xu-dong,GUO Zhen-hai.Investigation of Failure Mechanism and Internal Force Redistribution of Reinforced Concrete Continuous Beams at Elevated Temperature[J].Building Structure,1996,26(7):34-37.
[4]时旭东,过镇海.高温下钢筋混凝土连续梁的受力性能试验研究[J].土木工程学报,1997,30(4):26-34.
SHI Xu-dong,GUO Zhen-hai.Experimental Investigation of Behavior of Reinforced Concrete Continuous Beam at Elevated Temperature[J].China Civil Engineering Journal,1997,30(4):26-34.
[5]DWAIKAT M B,KODUR V K R.Response of Restrained Concrete Beams Under Design Fire Exposure[J].Journal of Structural Engineering,2009,135(11):1408-1417.
[6]DWAIKAT M B,KODUR V K R.A Numerical Approach for Modeling the Fire Induced Restraint Effects in Reinforced Concrete Beams[J].Fire Safety Journal,2008,43(4):291-307.
[7]WU B,LU J Z.A Numerical Study of the Behaviour of Restrained RC Beams at Elevated Temperatures[J].Fire Safety Journal,2009,44(4):522-531.
[8]吴 波,乔长江.混凝土约束梁升降温全过程的耐火性能试验[J].工程力学,2011,28(6):88-95.
WU Bo,QIAO Chang-jiang.Experimental Study on Fire Behaviors of RC Restrained Beams During Heating and Cooling Phases[J].Engineering Mechanics,2011,28(6):88-95.
[9]吴 波,乔长江.约束混凝土梁的升降温全过程轴力分析[J].建筑科学与工程学报,2010,27(1):12-20.
WU Bo,QIAO Chang-jiang.Axial Force Analysis of Restrained Concrete Beams During Heating and Cooling Phases[J].Journal of Architecture and Civil Engineering,2010,27(1):12-20.
[10]吴 波,乔长江.约束混凝土梁的升降温全过程弯矩分析[J].防灾减灾工程学报,2010,30(4):353-360.
WU Bo,QIAO Chang-jiang.Bending Moments of Restrained RC Beams During Heating and Cooling Phases[J].Journal of Disaster Prevention and Mitigation Engineering,2010,30(4):353-360.
[11]ALBRIFKANI S,WANG Y C.Explicit Modelling of Large Deflection Behaviour of Restrained Reinforced Concrete Beams in Fire[J].Engineering Structures,2016,121:97-119.
[12]韩 蕊,王广勇,薛素铎,等.受轴向约束的钢筋混凝土T形简支梁耐火性能研究[J].建筑科学,2016,32(9):34-40.
HAN Rui,WANG Guang-yong,XUE Su-duo,et al.Fire Performance of T-shaped Simply Supported Concrete Beams with Axial Constraints[J].Building Science,2016,32(9):34-40.
[13]ELGHAZOULI A Y,IZZUDDIN B A.Failure of Lightly Reinforced Concrete Members Under Fire.I:Analytical Modeling[J].Journal of Structural Engineering,2004,130(1):3-17.
[14]LI Z,LIU Y Z,HUO J S,et al.Experimental Assessment of Fire-exposed RC Beam-column Connections with Varying Reinforcement Development Lengths Subjected to Column Removal[J].Fire Safety Journal,2018,99:38-48.
[15]谭 炎.高温下钢筋混凝土梁-柱边节点竖向推覆试验研究[D].长沙:湖南大学,2016.
TAN Yan.Experimental Research on Push-down Test of RC Exterior Beam-column Connection at High Temperature[D].Changsha:Hunan University,2016.
[16]谭 炎,李 智,霍静思,等.锚固形式对火灾下边柱失效后RC梁柱节点受力机制影响试验研究[J].湘潭大学自然科学学报,2017,39(4):41-47.
TAN Yan,LI Zhi,HUO Jing-si.et al.Experimental Study on Mechanical Behaviour of RC Beam-column Connections with Different Anchorage Form Under Exterior Column Removal Induced by Fire[J].Natural Science Journal of Xiangtan University,2017,39(4):41-47.
[17]YI W J,HE Q F,XIAO Y,et al.Experimental Study on Progressive Collapse-resistant Behavior of Reinforced Concrete Frame Structures[J].ACI Structural Journal,2008,105(4):433-439.
[18]ELSAYED W M,ABDEL MOATY M A N A,ISSA M E.Effect of Reinforcing Steel Debonding on RC Frame Performance in Resisting Progressive Collapse[J].HBRC Journal,2016,12(3):242-254.
[19]钮 宏,陆洲导,陈 磊.高温下钢筋与混凝土本构关系的试验研究[J].同济大学学报:自然科学版,1990,18(3):287-297.
NIU Hong,LU Zhou-dao,CHEN Lei.An Experimental Study of Constitutive Relationship Between Reinforce Bar and Concrete Under Elevated Temperature[J].Journal of Tongji University:Natural Science,1990,18(3):287-297.
[20]杨建平,时旭东,过镇海.高温下钢筋混凝土压弯构件极限承载力简化计算[J].建筑结构,2002,32(8):23-25.
YANG Jian-ping,SHI Xu-dong,GUO Zhen-hai.Simplified Calculation of Ultimate Load Bearing Capacity of Reinforced Concrete Compression-bending Members at Elevated Temperature[J].Building Structure,2002,32(8):23-25.

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Last Update: 2020-01-13