Enhancing Effect of Rectangular Spiral Stirrups on the Fire Resistance of Concrete-Filled Rectangular Steel Tubular Columns

doi:10.12141/j.issn.1000-565X.250138

Abstract

Abstract:

Internal stirrup confinement can significantly enhance the fire resistance of concrete-filled steel tubular (CFST) columns. Even without any fire protection, this approach still enables the columns to meet the design requirements for the corresponding fire resistance rating, providing a novel method for structural fire protection design and enhancing the safe service life of structures. This paper designed and fabricated three full-scale rectangular CFST columns and conducted fire test on them under the combined effects of standard fire exposure and axial loading. The study investigated the fire performance enhancement of such members via internal rectangular spiral stirrups, and examined the influence of stirrup spacing on their fire resistance. Based on the existing mechanical constitutive models of materials at elevated temperature, this study developed a numerical model for rectangular CFST columns and revealed the mechanism by which the spiral stirrups constrain the core concrete to enhance the fire resistance. The research results indicate that, with equivalent or slightly lower total steel usage, the internal rectangular spiral stirrups can significantly improve the fire resistance of such columns, with an increase in fire resistance of up to 104.1%. By reasonably designing the stirrups parameters, this type of axially compressed column can meet the Class Ⅱ fire resistance rating requirements for 150 minutes without the need of a fire protection layer on the steel tube surface. When the stirrup spacing increases from 40 mm to 80 mm, its effect on the fire resistance of such members is relatively small. The established numerical model can effectively predict the fire resistance of rectangular CFST columns with internal rectangular spiral stirrups, but its accuracy in predicting deformation at different heating time is less satisfactory.

Key words: rectangular spiral stirrup, rectangular CFST column, fire resistance, stirrup spacing, confinement

CLC Number:

TU375.2

QIU Peiyun, ZANG Jianbo, WANG Xinxiang. Enhancing Effect of Rectangular Spiral Stirrups on the Fire Resistance of Concrete-Filled Rectangular Steel Tubular Columns[J]. Journal of South China University of Technology(Natural Science Edition), 2026, 54(2): 123-132.

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References 39

[1]	WANG Y C， DAVIES J M ．An experimental study of the fire performance of non-sway loaded concrete-filled steel tubular column assemblies with extended end plate connections［J］．Journal of Constructional Steel Research，2003，59（7）：819-838.
[2]	Design of composite steel and concrete structures，Part 1-2：general rules-structural fire design：EN 1994-1-2—2005 ［S］.
[3]	HAN L H， YANG Y F， XU L ．An experimental study and calculation on the fire resistance of concrete-filled SHS and RHS columns［J］．Journal of Constructional Steel Research，2003，59（4）：427-452.
[4]	ESPINOS A， ROMERO M L， SERRA E，et al ．Experimental investigation on the ﬁre behaviour of rectangular and elliptical slender concrete-filled tubular columns［J］．Thin-Walled Structures，2015，93：137-148.
[5]	RODRIGUES J P C， LAIM L ．Fire response of restrained composite columns made with concrete filled hollow sections under different end-support conditions［J］．Engineering Structures，2017，141：83-96.
[6]	戴戎．轴压矩形钢管再生混凝土抗火性能研究［D］．镇江：江苏科技大学，2019.
[7]	DU Y S， ZHANG Y T， LIU H B，et al ．Behaviors of restrained rectangular high-strength CFT column under elevated temperature［J］．Construction and Building Materials，2024，432：136616/1-20.
[8]	刘发起．三面受火的矩形钢管混凝土柱抗火性能研究［D］．哈尔滨：哈尔滨工业大学， 2010.
[9]	KIM S H， CHOI S M， YOM K S ．Improving fire performance with steel fibers for internally anchored square composite columns［J］．Journal of Constructional Steel Research，2014，103：264-274.
[10]	麻辉．恒高温下带钢筋加劲肋薄壁方钢管混凝土短柱力学性能研究［D］．阜新：辽宁工程技术大学，2015.
[11]	米振伟．带肋薄壁方钢管混凝土柱抗火性能研究［D］．阜新：辽宁工程技术大学，2017.
[12]	CHABOT M， LIE T T ．Experimental studies on the fire resistance of hollow steel columns filled with bar-reinforced concrete［R］．Ottawa：National Research Council of Canada，1992.
[13]	MYLLYMÄKI J， LIE T T， CHABOT M ．Fire resistance tests of square hollow steel columns filled with reinforced concrete［R］．Ottawa：National Research Council of Canada，1994.
[14]	LU H， HAN L H， ZHAO X L ．Fire performance of self-consolidating concrete filled double skin steel tubular columns：experiments［J］．Fire Safety Journal，2010，45（2）：106-115.
[15]	LU H， ZHAO X L， HAN L H ．Testing of self-consolidating concrete-filled double skin tubular stub columns exposed to fire［J］．Journal of Constructional Steel Research，2010，66（8/9）：1069-1080.
[16]	ROMERO M L， ESPINOS A， PORTOLÉS J M，et al ．Slender double-tube ultra-high strength concrete-filled tubular columns under ambient temperature and fire［J］．Engineering Structures，2015，99：536-545.
[17]	WAN C Y， ZHA X X， DASSEKPO J B M ．Analysis of axially loaded concrete filled circular hollow double steel tubular columns exposed to fire［J］．Fire Safety Journal，2017，88：1-12.
[18]	朱思懿，朱美春，郑丽兰，等．钢骨-钢管高强混凝土柱抗火性能试验研究［J］．上海师范大学学报（自然科学版），2014，43（3）：319-322．
	ZHU Siyi， ZHU Meichun， ZHENG Lilan，et al ．Experimental research on fire resistance of circular steel tube column filled with steel-reinforced high-strength concrete［J］．Journal of Shanghai Normal University（Natural Sciences），2014，43（3）：319-322．
[19]	朱美春，孟凡钦，何宝杰．型钢-钢管混凝土柱耐火性能试验研究［J］．建筑结构学报，2016，37（3）：36-43.
	ZHU Meichun， MENG Fanqin， HE Baojie ．Experimental research on fire resistance of steel tubular columns filled with steel reinforced concrete［J］．Journal of Building Structures，2016，37（3）：36-43.
[20]	ESPINOS A， ROMERO M L， LAM D ．Fire performance of innovative steel-concrete composite columns using high strength steels［J］．Thin-Walled Structures，2016，106：113-128.
[21]	NEUENSCHWANDER M， KNOBLOCH M， FONTANA M ．ISO standard fire tests of concrete-filled steel tube columns with solid steel core［J］．Journal of Structural Engineering，2017，143（4）：04016211/1-14.
[22]	SCHAUMANN P， KLEIBÖMER I ．Experimental and numerical investigations of the composite behaviour in concrete-filled tubular columns with massive steel core at high temperatures［J］．Journal of Structural Fire Engineering，2018，9（2）：147-160.
[23]	吴波，傅翼飞．内置高强角钢的方钢管再生块体混凝土柱轴压及耐火性能试验研究［J］．建筑结构学报，2020，41（5）：85-95.
	WU Bo， FU Yifei ．Test on compressive behavior and fire performance of square steel tubular columns filled with recycled 1ump concrete and high-strength steel angles［J］．Journal of Building Structures，2020，41（5）：85-95.
[24]	张强．内置横向约束的薄壁圆钢管再生混合混凝土柱的轴压和耐火性能研究［D］．广州：华南理工大学，2016.
[25]	臧建波．内置箍筋的方钢管再生块体混凝土柱的耐火性能及常温力学性能研究［D］．广州：华南理工大学，2021.
[26]	Building code requirements for structural concrete and commentary：ACI 318-11 ［S］．
[27]	矩形钢管混凝土结构技术规程：［S］．
[28]	金属材料拉伸试验第 1 部分：室温试验方法：［S］．
[29]	混凝土物理力学性能试验方法标准：［S］．
[30]	WU B， ZANG J B ．Effect of embedded steel stirrups on fire behavior of square steel tubular columns filled with recycled lump concrete ［J］．Engineering Structures，2020，211：110446/1-15.
[31]	Fire-resistance tests—elements of building construction—Part1：general requirements：［S］．
[32]	ROMERO M L， MOLINER V， ESPINOS A，et al ．Fire behavior of axially loaded slender high strength concrete-filled tubular columns［J］．Journal of Constructional Steel Research，2011，67（12）：1953-1965.
[33]	YANG H， LIU F Q， ZHANG S M，et al ．Experimental investigation of concrete-filled square hollow section columns subjected to non-uniform exposure［J］．Engineering Structures，2013，48：292-312.
[34]	SERĘGA S ．Effect of transverse reinforcement spacing on fire resistance of high strength concrete columns ［J］．Fire Safety Journal，2015，71：150-161.
[35]	DING J， WANG Y C ．Realistic modelling of thermal and structural behaviour of unprotected concrete filled tubular columns in fire［J］．Journal of Constructional Steel Research，2008，64（10）：1086-1102.
[36]	LIE T T， CHABOT M， IRWIN R J ．Fire resistance of circular hollow steel sections filled with bar-reinforced concrete［R］．Ottawa：National Research Council of Canada，1992.
[37]	HONG S， VARMA A H ．Analytical modeling of the standard fire behavior of loaded CFT columns［J］．Journal of Constructional Steel Research，2009，65（1）：54-69.
[38]	TAO Z， WANG Z， YU Q ．Finite element modelling of concrete-filled steel stub columns under axial compression［J］．Journal of Constructional Steel Research，2013，89：121-131.
[39]	IMANI R， MOSQUEDA G， BRUNEAU M ．Finite element simulation of concrete-filled double-skin tube columns subjected to postearthquake fires［J］．Journal of Structural Engineering，2015，141（12）：04015055/15.

试件编号	H/mm	B/mm	t/mm	B/t	H/t	S/mm
S0	400.0	250.0	5.7	70.2	43.9
S1	400.0	250.0	3.6	111.1	69.4	38.0
S2	400.0	250.0	3.6	111.1	69.4	80.0

材料	t/mm	d/mm	平均值/MPa		变异系数/%
材料	t/mm	d/mm	屈服强度	极限强度	屈服强度	极限强度
钢管	5.7		366.8	525.4	0.91	0.73
钢管	3.6		397.3	519.6	0.60	1.50
箍筋		10.0	455.0	646.8	1.72	0.62