Strengthening of a Steel Bridge Girder Using CFRP Plates

Miller, T.; Chajes, Michael J.; Mertz, Dennis R.; Hastings, Jason N.

doi:10.1061/(asce)1084-0702(2001)6:6(514)

Cited by 336 publications

(136 citation statements)

References 3 publications

Supporting

Mentioning

123

Contrasting

Unclassified

Order By: Relevance

“…Early research involved the application of CFRP materials for the repair of naturally deteriorated steel bridge girders (Mertz and Gillespie, 1996). Miller et al (2001) report a field application of this concept involving the bonding of CFRP strips to the tension flange of a heavily corroded bridge girder in an attempt to increase the member's capacity. This study evaluated the rehabilitation of four heavily corroded steel girders using single layers of full length CFRP plates bonded to the top and bottom surfaces of the deteriorated tension flange.…”

Section: Strengthening Steel Structuresmentioning

confidence: 99%

Conceptual Investigation of Partially Buckling Restrained Braces

Abraham¹,

Harries²

2007

Structural Engineering Research Frontiers

View full text Add to dashboard Cite

Although in its infancy, leveraging high strength fiber reinforced polymer (FRP) materials for retrofit of steel structures has been the focus of recent investigations. Studies include the application of FRP to steel for flexural and fatigue or fracture retrofit as well as improving steel member stability. The research presented in this thesis attempts to introduce the concept of an FRP-stabilized steel member through a retrofit application creating a Partially Buckling Restrained Brace (PBRB). A PBRB seeks to increase steel brace stability and hysteretic energy dissipation during a seismic event through the strategic application of bonded FRP materials along its length.Six 65 ½" long A992 Gr. 50 WT6x7 steel braces were tested under cyclic compressive loading to failure. Two braces were retrofitted with carbon FRP (CFRP) and two braces were retrofitted with glass FRP (GFRP). One brace was encased in an HSS 7 x 0.125" steel tube and filled with grout to create a conventional Buckling Restrained Brace (BRB). The final brace was an unretrofit control specimen. Two arrangements of FRP materials were used for both the CFRP and GFRP retrofit braces: (1) 2" wide strip was applied to each side of the stem of the WT, and (2) 1" wide strips were applied to each side of the stem in an effort to optimize the retrofit application.The GFRP specimens increased the axial capacity of the brace by 6% and 9%, whereas the CFRP specimens had no effect. The observed variability in axial capacity was largely a result iv of initial loading eccentricities. The GFRP specimens did however show greater control over residual deflections suggesting that the retrofit can delay the formation of a plastic hinge within the brace and maintain compressive capacity through several cyclic loading loops. All of the FRP-retrofit specimens reduced weak-axis lateral displacement of the braces and showed increased control of local behavior. However, the brace is not dominated by local behavior due to its length, and this application may be better suited to shorter braces, similar to those found as cross frames between bridge girders, or to control local buckling in steel I-shaped beams.v

show abstract

Section: Strengthening Steel Structuresmentioning

confidence: 99%

Conceptual Investigation of Partially Buckling Restrained Braces

Abraham¹,

Harries²

2007

Structural Engineering Research Frontiers

View full text Add to dashboard Cite

show abstract

“…The numerical study on strengthened steel structures [13,14] showed that the tapers with a beveled angle of 45° reduced the maximum shear and normal stresses by approximately 30% and 50% respectively, suggesting the usefulness of tapers in delaying the premature debond failure of CFRP plate. A closed-form analytical model was formulated [15,16] with special emphasis on the effects of adhesive spew-fillet at the FRP edge, vertically prestressed anchoring devices and the adhesive thickness.…”

Section: Introductionmentioning

confidence: 99%

“…The use of tapered FRP strips to control and reduce the edge stresses and thus to improve the load carrying capacity of various structures has been studied extensively [13][14][15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Strengthening efficiency of taper ended FRP strips bonded to RC beams

Gao

Kim

Leung

2006

Composites Science and Technology

View full text Add to dashboard Cite

Abstract:External bonding of fiber reinforced plastic (FRP) strips to reinforced concrete (RC) beams has been widely accepted as an effective method for strengthening and rehabilitation of aging civil structures. The FRP strips improve significantly the ultimate flexural strength of RC beams. This paper reports the effectiveness of taper end FRP design in further enhancing the structural performance of strengthened RC beams. The relative performance of taper distance was specifically evaluated in an effort to optimize the FRP strip end geometry for given RC beam dimensions. With rehabilitation of damaged and/or aging structures in mind, precracked RC beams were also studied. The four point bending experiment indicated that the tapered FRP strip end design augmented significantly the ultimate load and mitigated the reduction in beam deflection corresponding to the ultimate load, compared to the beams bonded with constant thickness FRP strips. There was negligible difference in flexural performance between the virgin and precracked RC beams after they were bonded with taper ended FRP strips, indicating that the tapered FRP design concept can be applied to both undamaged and aging/damaged structures.

show abstract

“…The method to achieve this purpose is using materials which can enhance tensile strength, cause high absorbing energy, and prevent buckling. Application of bonded Carbon Fiber Reinforced Plastic (CFRP) materials to strengthen steel structures has drawn the attention of many researchers and for more than a decade, several experimental and numerical investigations have been conducted to explore the behavior of externally bonded steel-CFRP lap connections [14,15].…”

Section: Introductionmentioning

confidence: 99%

Numerical modelling of the mechanical behaviour of steel brace modified by CFRP sheet

2017

View full text Add to dashboard Cite

Abstract. One of the de ciencies of diagonal (X) bracing is buckling under compressive load, hence not reaching the yielding threshold and being unstable. In this numerical study, the behavior of X-shape brace was investigated, which was modi ed by Carbon Fiber Reinforced Polymer (CFRP) plates that could absorb compressive force and make it stable. This innovative brace consisted of two separate steel plates connected by CFRP sheets to each other in the middle of the compressive element. Thus, these two parts were connected by epoxy resin and bolts. In this study, Finite Element Method (F.E.M.) was used to simulate the elements of steel and ber polymers by Abaqus software under cycle loading after designing of ber layers and connection type. Also, the numerical result was compared with the normal steel brace. The result showed that the innovative brace had more e ciency under seismic response. According to this output, ductility and energy absorption increased in the innovative model (CFRP-BR), but sti ness decreased as compared with the normal steel brace.

show abstract

Strengthening of a Steel Bridge Girder Using CFRP Plates

Cited by 336 publications

References 3 publications

Conceptual Investigation of Partially Buckling Restrained Braces

Conceptual Investigation of Partially Buckling Restrained Braces

Strengthening efficiency of taper ended FRP strips bonded to RC beams

Numerical modelling of the mechanical behaviour of steel brace modified by CFRP sheet

Contact Info

Product

Resources

About