This paper presented a comprehensive assessment of 22 existing stress models and 13 strain models, which were developed for glass fiber reinforced polymer (GFRP)-confined concrete in uniaxial compression. In addition, a reliability evaluation of these stress and strain models was performed. A database including 212 GFRP-confined cylindrical concrete specimens was collected and analyzed to evaluate the performance of these stress and strain models. The accuracy and applicability assessment of these models were carried out by test and the Pearson correlation coefficient r, and the Monte Carlo–JC method was used by for the reliability assessment. Based on the evaluation, it was found that the unconfined concrete strength is the most important parameter which determines the accuracy of these stress and strain models for GFRP-confined concrete. Most stress and strain models used in this study can predict the ultimate axial strength and strain of the GFRP-confined concrete appropriately, although some scattered points exist for some models. In addition, it was found that all these models satisfy the command of reliability even some models are too conservative. Based on the database, unified stress and strain models were proposed showing better applicability.
RichartFEBrandtzaegABrownRL. A study of the failure of concrete under combined compressive stresses, Champaign: University of Illinois, 1928.
2.
FardisMNKhaliliH. FRP-encased concrete as a structural material. Magaz Concr Res1982; 34: 191–202.
3.
MirmiranAShahawyM. Behavior of concrete columns confined by fiber composites. ASCE J Struct Eng1997; 123: 583–590.
4.
SaafiMToutanjiHALiZ. Behavior of concrete columns confined with fiber reinforced polymer tubes. ACI Mater J1999; 96: 500–509.
5.
SamaanMMirmiranAShahawyM. Model of concrete confined by fiber composite. ASCE J Struct Eng1998; 124: 1025–1031.
6.
ManderJBPriestleyMJNParkR. Theoretical stress-strain model for confined concrete. ASCE J Struct Eng1988; 114: 1804–1826.
7.
Miyauchi K, Nishibayashi S and Inoue S. Estimation of strengthening effects with carbon fiber sheet for concrete column. In: 3rd international symposium of non-metallic reinforcement for concrete structures, Sapporo, Japan, 1997.
8.
MiyauchiKInoueSKurodaT. Strengthening effects with carbon fiber sheet for concrete column. Jpn Concr Inst1999; 21: 1453–1458.
9.
KarbhariVMGaoY. Composite jacketed concrete under uniaxial compression - verification of simple design equations. J Mater Civil Eng1997; 9: 185–193.
10.
ToutanjiHA. Stress-strain characteristic of concrete columns externally confined with advanced fiber composite sheets. ACI Mater J1999; 96: 397–404.
11.
TengJGChenJFSmithST. Strengthened RC structures. China Archit Build Press2006; 6: 149–185.
12.
TengJGJiangTLamL. Refinement of a design-oriented stress–strain model for FRP-confined concrete. ASCE J Compos Construct2009; 13: 269–278.
13.
MatthysSToutanjiHAudenaertK. Axial load behavior of large-scale columns confined with FRP composites. ACI Struct J2005; 102: 258–267.
14.
MatthysSToutanjiHAudenaertK. Axial load behavior of large scale columns confined with fiber-reinforced polymer composites. ACI Struct J2005; 102: 258–267.
15.
ShehataIAEMCarneiroLAVShehataLCD. Strength of short concrete columns confined with CFRP sheets. Mater Struct2002; 35: 50–58.
16.
Shehata IAEM, Carneiro LAV and Shehata LCD. Strength of confined short concrete columns. In: Proceedings of 8th international symposium on fiber reinforced polymer reinforcement for concrete structures, Patras, Greece, 2007.
17.
VintzileouEPanagiotidouE. An empirical model for predicting the mechanical properties of FRP-confined concrete. Construct Build Mater2007; 22: 841–854.
18.
WuYFWangL. Unified strength model for square and circular concrete columns confined by external jacket. ASCE J Struct Eng2009; 135: 253–261.
19.
Wei YY and Wu YF. Unified stress–strain model of concrete for FRP-confined columns. Constr Build Mater 2012; 26: 381–392.
20.
FahmyMFMWuZ. Evaluating and proposing models of circular concrete columns confined with different FRP composites. Compos Part B: Eng2010; 41: 199–231.
21.
OzbakkalogluTLimJCVincentT. FRP-confined concrete in circular sections: Review and assessment of stress–strain models. Eng Struct2013; 49: 1068–1088.
22.
IBM SPSS advanced training course, China: Yanshu Data of Shanghai, 2015.
23.
HeZHuangYC. Application of Monte Carlo-JC method to the reliability assessment of flexural capacity of RC beams strengthened with FRP. Acta Mater Compos Sin2007; 24: 116–121.
24.
RackwitzRFiesslerB. Structure reliability under combined random sequences. Comput Struct1978; 9: 489–494.
25.
SinghVJainSTyagiA. Monte Carlo simulation. Risk Reliab Anal2007; 11: 437–485.
26.
Demers M and Neale KW. Strengthening of concrete columns with unidirectional composite sheets. In: Development in short and medium span bridge engineering’ 94, Canadian Society for Civil Engineering, Montreal, 1994, pp. 895–905.
Aire C, Gettu R and Casas JR. Study of the compressive behavior of concrete confined by fiber reinforced composites. In: Proceedings of international conference on composites in constructions, 2001, pp. 239–243. Lisse, The Netherlands: A.A. Balkema Publishers.
29.
Abdollahi B, Bakhshi M, Motavalli M, et al. Experimental modeling of GFRP confined concrete cylinders subjected to axial loads. In: Proceedings of the 8th international symposium on fiber reinforced polymer reinforcement for concrete structures, Patras, Greece, 2007.
30.
AhmadSMKhalooARIrshaidA. Behaviour of concrete spirally confined by fiberglass filaments. Magaz Concr Res1991; 43: 143–148.
31.
AlmusallamTH. Behaviour of normal and high-strength concrete cylinders confined with E-glass/epoxy composite laminates. Compos Part B: Eng2007; 38: 629–639.
32.
AuCBuyukozturkO. Effect of fiber orientation and ply mix on fiber reinforced polymer-confined concrete. ASCE J Compos Construct2005; 9: 397–407.
Bullo S. Experimental study of the effects of the ultimate strain of fiber reinforced plastic jackets on the behavior of confined concrete. In: Proceedings of the international conference composite in construction, Cosenza, Italy, 2003.
35.
Carey SA. Behavior of variably confined concrete. Honors Thesis, University of South Carolina, USA, 2002.
36.
Comert M, Goksu C and Ilki A. Towards a tailored stress–strain behavior for FRP confined low strength concrete. In: Proceedings of 9th international symposium on fiber reinforced polymer reinforcement for concrete structures, Sydney, Australia, 2009.
37.
CuiCSheikhSA. Experimental study of normal- and high-strength concrete confined with fiber-reinforced polymers. J Compos Construct2010; 14: 553–561.
38.
Demers M and Neale KW. Strengthening of concrete columns with unidirectional composite sheets. In: Proceedings of 4th international conference on short and medium span bridges, Montreal, Canada, 1994, pp. 895–905.
39.
GreenMFBisbyLAFamAZ. FRP confined concrete columns: Behaviour under extreme conditions. Cem Concr Res2006; 28: 928–993.
40.
HarriesKACareyA. Shape and ‘gap’ effects on the behavior of variably confined concrete. Cem Concr Res2002; 33: 873–880.
41.
HarriesKAKharelG. Behavior and modeling of concrete subject to variable confining pressure. ACI Mater J2002; 99: 180–189.
LiGMaricherlaDSinghK. Effect of fiber orientation on the structural behavior of FRP wrapped concrete cylinders. J Compos Struct2006; 74: 475–483.
47.
LinHJChenCT. Strength of concrete cylinder confined by composite materials. J Reinf Plast Compos2001; 20: 1577–1600.
48.
MandalSHoskinAFamA. Influence of concrete strength on confinement effectiveness of fiber-reinforced polymer circular jackets. ACI Struct J2005; 102: 383–392.
49.
Mastrapa JC. Effect of construction bond on confinement with fiber composites. Masters, University of Central Florida, USA, 1997.
50.
Micelli F, Myers JJ and Murthy S. Effect of environmental cycles on concrete cylinders confined with FRP. In: Proceedings of international conference on composites in construction, Porto, Portugal, 2001.
51.
MicelliFModarelliR. Experimental and analytical study on properties affecting the behaviour of FRP-confined concrete. Compos Part B: Eng2013; 45: 1420–1431.
52.
MirmiranAShahawyMSamaanM. Effect of column parameters on FRP-confined concrete. ASCE J Compos Construct1998; 2: 175–185.
ShaoYZhuZMirmiranA. Cyclic modeling of FRP-confined concrete with improved ductility. Cem Concr Res2006; 28: 959–968.
55.
PessikiSHarriesKAKestnerJ. The axial behavior of concrete confined with fiber reinforced composite jackets. J Compos Construct2001; 5: 237–245.
56.
SilvaMAGRodriguesCC. Size and relative stiffness effects on compressive failure of concrete columns wrapped with glass FRP. ASCE J Mater Civil Eng2006; 18: 334–342.
57.
Suter R and Pinzelli R. Confinement of concrete columns with FRP sheets. In: Proceedings of 5th symposium on fibre reinforced plastic reinforcement for concrete structures, London, 2001.
Load code for the design of building structures GB50009-2001. Beijing: China Architecture and Building Press, 2001.
66.
ACI 318. Building code requirements for structural concrete (ACI 318-08) and commentary (ACI 318-08) [S], Farmington, MI: ACI, 2008.
67.
Newman K and Newman JB. Failure theories and design criteria for plain concrete. In: Proceedings of international civil engineering materials conference on structure, 1969. New York: Wiley Interscience.
SaadatmaneshHEhsaniMRLiMW. Strength and ductility of concrete columns externally reinforced with fiber composite straps. ACI Struct J1994; 91: 434–447.
71.
ACI 440.2R-02. Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures, Farmington, MI: American Concrete Institute, 2002.
72.
ShahawyMMirmiranABeitelmanA. Test and modeling of carbon-wrapped concrete columns. Compos Part B: Eng2000; 31: 471–480.
73.
Unified standard reliability design of building structures GB50068-2001, Beijing: China Architecture and Building Press, 2001.
74.
ACI 318. Building code requirements for structural concrete (ACI 318-08) and commentary (ACI 318-08) [S], Farmington, MI: ACI, 2008.
