1. REPAIR OF TIMBER BEAMS USING CFRP SHEETS
Ali AWALUDIN, Afriza MARIANTI
Department of Civil and Environmental Engineering, University of Gadjah Mada

2. Exposed wooden house

3. Exposed timber bridge structure

4. OUTLINE Introduction Materials and Methods Result and Discussion
Conclusion

5. INTRODUCTION RETROFITTING OR RENEWAL?? Historical buildings
CAUSES
Fungus  Decay
Bacteria  Decay
Borer insects (termites)
Earthworms
Mechanical wear
RETROFITTING OR RENEWAL??
Historical buildings

6. INTRODUCTION What is CFRP?
Composite material consisting of carbon fibers which provides strength, stiffness, load carrying capacity, and a polymer matrix
Type and orientation of carbon fiber
Type and percentage of resin material
Curing condition
Engineering properties depend on

7. INTRODUCTION GOALS Moment Capacity Deformation Stiffness
Failure Mechanism

8. Materials and Methods REPAIR MATERIAL CFRP SCH-11
Tensile strength: 3790 MPa
Tensile modulus: 230 GPa
Ultimate elongation: 1.7%

9. Materials and Methods SPECIMENS 2000 mm 95 mm 55 mm 900 mm Timber used
Meranti (Shorea spp.)
Average density
851 kg/m3
Moisture content
17%
55 mm
95 mm
2000 mm
Decay
Artificial crack (depth 25 mm, a width of 2 mm)
900 mm

10. Materials and Methods L = Distance between two supports1
0,33L
2000 mm
CFRP-900 mm
1800 mm 2
0,5L
2000 mm
1800 mm
CFRP-1800 mm 3 L
L = Distance between two supports
Crack depth is 25 mm

11. Materials and Methods Properties of beam specimens No Name Group Name
MoEd
(Mpa)
CFRP Length (mm)
CFRP Width (mm) 1 A
14039 NA 2
B-600 B
13158
600 55 3
B-900
13301
900 4
B-1800
11444
1800 5
C-600 C
17896
115 6
C-900
16330 7
C-1800
18287

12. Materials and Methods Four-point loading test ½ P 1800 mm 2000 mm
CFRP-600 mm
½ P
LVDT 1,2
LVDT 3
LVDT 4

13. Increase of moment capacity Increase of bending stiffness
Result
Specimen
Maximum load
 (kN)
Moment capacity
(kNm)
Bending stiffness, EI
(Nmm2)
Increase of moment capacity
(%)
Increase of bending stiffness A
9.78
2.98
53.07 -
B-600
18.46
5.59
59.19 87 12
B-900
18.92
5.72
62.16 92 17
B-1800
22.43
6.78
60.36
127 14
C-600
17.83
5.40
60.00 81 13
C-900
21.85
6.60
59.00
121 11
C-1800
30.65
9.24
63.39
210 19

14. Result GROUP A and B GROUP A and C Beam C-1800 Beam B-1800 Beam C-900
Beam A
Beam A

15. Result (Failure Mode)
Beam C-600
Beam B-600
Beam C-1800
Beam C-900

16. Conclusion
CFRP reinforcement significantly increase the bending capacity of the cracked beam
Increase of bending capacity in group C is much higher than group B
This increase of bending capacity is a function of length of CFRP reinforcement
Significant increase of bending capacity is followed by small increase of bending stiffness
Increase of bending stiffness is about the same for three different lengths and two different width of CFRP: 11% to 19%

17. PT. Fyfe Fibrwrap Indonesia
Acknowledgement
PT. Fyfe Fibrwrap Indonesia
to provide CFRP and share the data properties used in this study

18. THANK YOU