Fatigue Characteristic of RC Beams Strengthen with CFRP Strand sheet

B4 Junpei Kasai

Today’s Topic

・ Background & Purpose

・ Experiment & Result

・ Future plan

Background & Purpose

Static behavior clear

Fatigue behavior unclear

To make fatigue behavior clear

To analyze residual strength after 2milion fatigue load

Experiment & Result

・ SpecimenMaximum load 90kN

Minimum load　 10kN

Experiment & Result

Figure of Crack

Experiment & Result

Figure of Crack

Experiment & Result

・ Failure model１ layer Bending failure

Maximum load 250kN

Debonding occur at end of sheet ２ layer Bending failure

　　　　　 Maximum load 260kN 　

　　　 Debonding occur at end of sheet

Experiment & Result

Load-displacement at loading point of 1 layer

0

50

100

150

200

250

300

350

0 5 10 15 20

displacement mm)（

Load

KN)

（

1100

1,00010,000100,0001milion

2milionstatic

Experiment & Result

Load-displacement at loading point of 1 2ayer

0

50

100

150

200

250

300

350

0 5 10 15 20

displacement(mm)

Load

KN)

（

11001,00010,000100,0001milion2milionstatic

Experiment & Result

Maximum load

Static After fatigue

1layer 278kN 250kN

2layers 315kN 260kN

Enough residual strength

Experiment & Result

Strain of sheet1layer

0

500

1000

1500

2000

0 10 20 30 40 50 60 70

Distance from supporting point（ｃｍ）

str

ain

μ（

ｍ）

1

100

1,000

10,000

100,000

1milion

2milion

2layers

0

500

1000

1500

2000

0 10 20 30 40 50 60 70

Distance from the supporting point（ｃｍ）

str

ain

μ（

ｍ）

1

100

1,000

10,000

100,000

1milion

2milion

Experiment & Result

Strain of sheet

The number of loads increase

Strain of sheet increase

Strain of sheet

1layer ＞ 2layer

Experiment & Result

- 1.5- 1

- 0.50

0.5

11.5

22.5

0 10 20 30 40 50 60 70

Distance from the supporting point（ｃｍ）

Str

ess

N/m

m)

（

1

100

1,000

10,000

100,000

1milion

2milion

Bond stress of sheet

-2.5-2

-1.5

-1-0.5

00.5

1

1.52

2.5

0 10 20 30 40 50 60 70

Distance from the supporting point（ｃｍ）

Str

ess

N/m

m)

（

1

100

1,000

10,000

100,000

1milion

2milion

Experiment & Result

Bond stress of sheet

1layer ＞ 2layers

Sheet debonding

Bond stress move

Future plan

Static　 test～　 2009 　 Dec　 242009 Dec 25 ～ Analysis & Thesis

Thank you for your kind attention !!