KETUA PENYELIDIK: PROF. Ir. DR. ABDUL AZIZ BIN DATO' ABDUL SAMAD. AHLI PEWl3LIDIK: PM DR. J. JAYAPRAKASH

Transcription

1 DEVELOPMENT OF A COMPATIBILITY MODEL FOR TqE SHEAR STRENGTHENING OF REINFORCED CONCRETE CONTINUOUS BEAMS USING EXTERNALLY BONDED BI-DIIIECTIONAL CFRP STRIPS KETUA PENYELIDIK: PROF. Ir. DR. ABDUL AZIZ BIN DATO' ABDUL SAMAD AHLI PEWl3LIDIK: PM DR. J. JAYAPRAKASH GERAN PEWELIDIKAN FUNDAMENTAL RESEARCH GRANT SCHEME NO. VOT: 0708 UNIVERSITI TUN HUSSEIN OMV MGLAYSIA

2 ABSTRACT The behaviour of reinforced concrete in shear is very complex and structure that fails in shear was dangerous than flexural failure because shear failure usually occurs suddenly and without any warning. It has been found out that many of existing reinforced concrete structures are deficient is shear 'md needs to be repaired. Therefore, this study tends to investigate the shear behaviour of reinforced concrete beams strengthened and repaired using Carbon Fibre Reinforced Polymer (CFRP) composites. An experimental work on ten reinforced concrete continuous beams has been conducted. The parameter involved in this study was shear span to effective depth ratio, wrapping schemes and CFRP strips orientation. All beams fails in shear as expected. Modes of failure for beams wrapped at three sides of the beam were debonding and rupture of the CFRP strips while beams wrapped at four sides of the beam fails in rupture of the CFRP strips. The highest shear capacity enhancement was for beam wrapped at four sides of the beam with 45"/135* orientation of the CFRP strips. From the experimental resuits, it can be concluded that wrapping schemes influences the shear capacity and diagonal crack angle of the beam. It was also important to notice that for continuous beams, due to the complexity of the high shear and bending moment region, the critical area (inner shear span) of the high shear area should be strengthened more than the outer shear span of the beam.

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31 ACI Committee 440 (2006). "Report on Fiber-Reinforced Polymer (FRP) Reinforcement for Concrete Structures." ACI Committee 318, Building code requirements for struc~alconcrete (ACI ), American Concrete Institute, Detroit, ACT Committee 440 (2008). "Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures." Adhikary, B.B. and Mutsuyoshi, H. (2004) "Behavior of Concrete Beams Strengthened in Shear with Carbon-Fiber Sheets." Journal of Composites for Construction Balaguru, P., Nanni, A. and Giancaspro. J. (2009). "FRP Composites for Reinforced and Prestress Concrete Structures". Taylor & Francis Group USA. Bank, L.C. (2006), Composite for Construction: Structural Design with FRP Materials. Chajes, M.J., Januszka, T.F., Mertz, D.R., Thornson, T.A.J. and Finch, W.W.J (1995). "Shear Strengthening of Reinforced Concrete Beams using Externally Applied Composite Fabrics." ACIStructural Journal Cusson,R and Xi, Y. (2002). "The Behaviour of Fiber-Reinforced Polymer Reinforcement in Low Temperature Environmental Climates". Department of Civil, Environmental and Architectural Engineering, University of Colorado. pp EI-Refaie, S.A., Ashour, A.F. and Garrity, S. W. (200 1). "Strengtheing of Reinforced Concrete Continuous Beams with CFRP Composites." Proceedings of the International Conference on Structural Engineering, Mechanics and Computation, Cape Town, South AAJiica, Elsevier El-Sayed, A.K. and Soudki,. K. (2010). "Evaluation of Shear Design Equation of Concrete Beam with FRP Reidorcement." Construction 15, No. I Journal of Composites for Grace, N. F., Soliman, A.K. Abdel Sayed, G and Saleh K.R. (1998). "Behaviour and Ductility of Simply and Continuous FRP Reinforced Beams." Journal of Composites for Construction

32 Gravina, R.J. and Smith, S.T. (2008). "FIexuraI Behaviour of Indeterminate Concrete Beams Reinforced with FRP Bars." Engineering Structures 30. No Hanus, J.P, Bank, L.C. and Oliva, M.G. (2009). "Combined Loading of a Bridge Deck Reinforced with a Structural FRP Stay-in-Place From". Construction and Building Materials 23, No Jayaprakash.J.(2006).Shear Strengthening of reinforced Concrete Beams Using Externally Bonded BI-Directional CFRP. Universiti Putra Malaysia: Ph.D.Thesis. Khalifa, A. and Nanni, A. (2002) "Rehabilitation of Rectangular Simply Supported RC Beams with Shear Deficiencies using CFRP Composites." Construction and Building Materials Khalifa, A. and Nanni, A. (2000) "Improving Shear Capacity of Existing RC T-Section Beams using CFRP Composites." Cement and Concrete Composites Khalifa, A., Tumialan, G., Nanni, A. and Belarbi, A. (1999) "Shear Strengthening of Continuous RC Beams using Externaliy Bonded CFRP Sheets." American Concrete Institute, Proceedings of 4fh International Symposium on FRP for Reinforcement of Concrete Structures (FRPRCS4), Baltimore KhaIifa, A. Gold, W.J., Nanni, A. and Abdel Aziz, M.1. (1998). "Contribution of Externally Bonded FRP to Shear Capacity of RC Flexural Members." Journal of Composites for Construction Kodur, V.K.R. and Baingo, D. (1999). "Evaluation of Fire Resistancee of FRPreinforced Concrete Slabs." Leung, C.K.Y. and Pan, J (2005). "Effect on Concrete Composition on FRPIConcrete Bond Capacity." Department of Civil Engineering, HKUST. Proceedings of the International Symposium on Bond Behaviour offrp in Structure (BBFS 2005) Li, G., Maricherla, D., Singh, K., Pang, S.S. and John, M. (2006). " Effect of Fiber Orientation on the Structural Behavior of FRP Wrapped Concrete Cylinders." Composite Structures MacGregor, J.G. and Bartlet, F.M. (2000). "Reinforced Concrete-Mechanics and Design." Prentice-Hall, Canada, Ontario.