07 Research GRINZI Nagy-Gyorgy T

8/11/2019 07 Research GRINZI Nagy-Gyorgy T

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FLEXURAL CAPACITY INCREASE OF RC

BEAMS BY APPLYINGFRP COMPOSITES WITH ANCHORAGE

Tams Dan ValeriuNAGY-GYRGY DIACONU STOIAN

PhD, Lecturer PhD, Assist. lect. PhD, Professor


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FLEXURAL CAPACITY INCREASE OF RC BEAMS BY APPLYING FRP-S WITH ANCHORAGE

SPAN: 400 CMREFERENCE BEAM 1 (RB): 316

RETROFITTED SPECIMENS: 216

SYSTEMS WERE USED, WHICH WERE DESIGNED TO REACH AN

APPROPRIATE LOAD BEARING CAPACITY AS THE FIRST

REFERENCE BEAM (RB).


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TEST SET-UP

stirrups 8/15 28

21640

130 140 130 20

400


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TEST SET-UP


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R-2W

strengthened with 2 layer of 18cm wide unidirectional carbon FPR fabric


in the bottom part, without any anchor system.


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TEST RESULTS


R-2W strengthened with 2 layer of 18cm wide unidirectional carbon FPR fabricin the bottom part, without any anchor system.Failure: debonding of the FRP.

140

160

180

200

220

]

RB

R-2W

40

60

80

100

120

LOAD

[k

0

20

0 25 50 75 100 125

DEFLECTION [mm]


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RL-2W-A strengthened with 2 layer of 9cm wide unidirectional carbon FPR fabric


, .


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TEST RESULTS


RL-2W-A strengthened with 2 layer of 9cm wide unidirectional carbon FPR fabricapplied in the lateral part of the both side, anchored with three spikes/end/side.Failure: debonding inside the FRP.

140

160

180

200

220

]

RB

RL-2W-A

40

60

80

100

120

LOAD

[k

0

20

0 25 50 75 100 125

DEFLECTION [mm]


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R-2W-A strengthened with 2 layer of 18cm wide unidirectional carbon FPR fabric

-


, .

9

9

1 . 2

= 1 2 - a n c o r a j / 1 4 - g a u r a =


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R-2W-A strengthened with 2 layer of 18cm wide unidirectional carbon FPR fabric

-


, .Failure: debonding of the fiber sheets, followed by fracture near the anchorage zone


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R-2W-MA

strengthened with 2 layer of 18cm wide unidirectional carbon FPR


fabric applied in the bottom part of beam, anchored with metal anchors.


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R-2W-MA strengthened with 2 layer of 18cm wide unidirectional carbon FPRfabric applied in the bottom part of beam, anchored with metal anchors.


,pieces with crushing of the compressed concrete.


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TEST RESULTS


-bottom part and anchored at the ends with steel plates.Failure: began with the FRP debonding between the anchorages, followed byconcrete crushing in the compression zone, and finally by the sliding out of the FRPfrom the anchorage simultaneous with the failure of the strip.

160

180

200

220

RB

R-1S

60

80

100

120

140

LOAD

[kN]

RB2

0

20

40

0 25 50 75 100 125

DEFLECTION [mm]


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R-2NSMS strengthened with two 20mm wide carbon FPR strip, in the bottom


, .


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-

TEST RESULTS


,part of the beam, applied in cut grooves (NSM technique).Failure: began with the composite debonding in the grooves, followed by concretecrushing in the compression zone, and finally by the tensile failure of the FRP stripin the middle region of the beam.

160

180

200

220

RBR-2NSMS

60

80

100

120

140

LOAD

[kN]

RB2

0

20

40

0 25 50 75 100 125

DEFLECTION [mm]


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R-2S-W strengthened with 1 layer of 5cm wide CFPR strip applied in the bottom


.

400

200


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R-2S-W strengthened with 1 layer of 5cm wide CFPR strip applied in the bottom


.Failure: partial sliding of the strip because of the shear failure of the sheets, followedby rupture.


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R-1S-AS strengthened with 1 layer of 5cm wide CFPR strip applied in the bottom


and top part anchored with anchor spikes.


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R-1S-AS strengthened with 1 layer of 5cm wide CFPR strip applied in the bottom


.


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TEST RESULTS


R-1S-AS strengthened with 1 layer of 5cm wide CFPR strip applied in the bottomand top part anchored with anchor spikes.Failure: debonding of the strip at the anchorage and than by slipping.


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R-1S-SP strengthened with 1 layer of 5cm wide CFPR strip applied in the bottom


.


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R-1S-SP strengthened with 1 layer of 5cm wide CFPR strip applied in the bottom

and top part anchored with steel plates.


Failure: debonding and slipping of the strip in the anchorage and than failure of thestrip.


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R-1S-CA strengthened with 1 layer of 5cm wide CFPR strip applied in the bottom


.


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.


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.Failure: concrete crushing and strip failure.


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BASED ON THE PERFORMED EXPERIMENT, RESPECTIVELY ON

CONCLUSIONS

THE BEHAVIOUR OF THE TESTED SPECIMENS, THE FAVOURABLE

EFFECTS OF MECHANICAL AS WELL AS CHEMICAL ANCHORAGEWERE EXPERIMENTALLY DEMONSTRATED, BOTH FOR BOTTOM AND

.

INCREASING OF THE FLEXURAL CAPACITY OF REINFORCEDCONCRETE BEAMPROVED TO BE THE NSM TECHNIQUE


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CONCLUSIONS

220

180

200

RB

R-1S

120

140

[kN]

RB2R-2WRL-2W-A

60

80

100

LOA

0

20

40

0 25 50 75 100 125

DISPLACEMENT [mm]

Documents

07 Research GRINZI Nagy-Gyorgy T