Effect of Composite Wrap Architecture on Strengthening of Concrete Due to Confinement: II-Strain and Damage Effects

Abstract

The increasing deterioration of infrastructure due to the combined effects of aging and environmental weathering, including the detrimental effect of salt and chlorides has created a critical problem related to rehabilitation and renewal. The use of composite wraps on deteriorated concrete piers and columns presents a potentially rapid and efficient means of strengthening the structure, as well as providing a coating that serves to protect the previously weakened structure from further environmental exposure and degradation. This study investigates the use of unidirectional carbon fabric used as an overlay on column specimens for the purposes of strengthening. Specimens wrapped with a variety of fiber orientations and number of layers were loaded statically under uniaxial compression. Experimental results on strain and damage effects are discussed and related to wrap architecture. Experimental results indicate significant enhancement of strength and pseudo-ductility of the specimens, and experimental results provide a good basis for the understanding of the interaction between the wrap and the dilated concrete.

Keywords

composite wraps concrete confinement strengthening

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References

1. Richart, F. E. , A. Brandtzaeg and R. L. Brown . 1928. "A Study of Failure of Concrete under Combined Compressive Stresses," Engineering Experiment Station Bulletin No. 185, University of Illinois, Urbaba, IL.

2. Richart, R. D. , A. Brandtzaeg and R. L. Brown . 1929. 'The Failure of Plain and Spiral Reinforced Concrete in Compression" Engineering Experiment Station Bulletin No. 190, University of Illinois, Urbana, IL.

3. Chan, W. W. L. 1955. "The Ultimate Strength and Deformation of Plastic Hinges in Reinforced Concrete Frameworks," Magazine of Concrete Research, 7(21):121-132.

4. Knowles, R. B. and R. Park . 1969. "Strength of Concrete Filled Tubular Columns," ASCE Journal of Structural Engineering, 95(ST12):2565-2587.

5. Furlong, R. W. 1967. "Strength of Steel-Encased Concrete Beam Columns," Journal of the Structural Division, Proceedings of the American Society of Civil Engineers, 93(ST5):113-124.

6. Iyengar, S. R. , P. Desayi and K. N. Reddy . 1970. "Stress-Strain Characteristics of Concrete Confined in Steel Binders," Magazine of Concrete Research, 22(72):173-184.

7. Morales, S. M. , A. H. Nilson and F. O. Slate . 1982. "Spiral-Reinforced High Strength Concrete Columns," Report No. 82-10, Department of Structural Engineering, Cornell University.

8. Mander, J. B. , M. J. N. Priestley and R. Park . 1988. "Theoretical Stress-Strain Model for Confined Concrete," ASCE Journal of Structural Engineering, 114(8):1804-1826.

9. Mander, J. B. , M. J. N. Priestley and R. Park . 1988. "Observed Stress-Strain Model for Confined Concrete"' ASCE Journal of Structural Engineering, 114(8):1827-1849.

10.

10. Chai, Y. H. , M. J. N. Priestley and F. Seible . 1991. "Seismic Retrofit of Circular Bridge Columns for Enhanced Flexural Performance," ACI Siructural Journal, 88(5):572-584.

11.

11. Katsumata, H. , Y. Kobatake and T. Takeda . 1988. 'A Study on Strengthening with Carbon Fiber for Earthquake-Resistant Capacity of Existing Reinforced Concrete Columns"' Proceedings of the 9th World Conference on Earthquake Engineering, Vol VII, Tokyo, pp. 517-522.

12.

12. Katsumata, H. and K. Kimura . 1990. 'Applications of Retrofit Method with Carbon Fiber for Existing Reinforced Concrete Structures," Proceedings of the 22nd UJNR Panel Meeting, US. -Japan Workshop, Gaithersburg, MD, pp. 1-28.

13.

13. Hasegawa, A. , T. Matsuda and N. Higashida . 1992. "Carbon Fiber-Reinforced Earthquake-Resistant Retrofitting for RC Piers," Doboku Gijutso, 97(3):43-50.

14.

14. Fardis, M. N. and H. H. Kalili . 1982. "FRP-Encased Concrete as a Structural Materials," Magazine of Concrete Research, 34(121):191-202.

15.

15. Priestley, M. J. N. , F. Seible and E. Fyfe . 1992. "Column Seismic Retrofit Using Fiberglass/Epoxy Jackets," Proceedings of the Ist International Conference on Advanced Composite Materials in Bridges and Structures, Sherbrooke, Canada, pp. 287-298.

16.

16. Karbhari, V. M. , D. A. Eckel, II and G. C. Tunis, III . 1993. "Strengthening of Concrete Column Stubs through Resin Infused Composite Wraps," Journal of Thermoplastic Composite Materials, 6(April):92-107.

17.

17. Picher, F. , P. Rochette and P. Labossiere . 1996. "Confinement of Concrete Cylinders with CRFP," Proceedings of the Ist International Conference on Composites in Infrastructure, Tucson, AZ, pp. 829-841.

18.

18. Nanni, A. and M. S. Norris . "FRP Jacketed Concrete under Flexure and Combined Flexure-Compression," Construction and Building Materials, 9(5):273-281.

19.

19. Nanni, A. and N. M. Bradford . 1995. "FRP Jacketed Concrete under Uniaxial Compression," Construction and Building Materials, 9(2):115-124.

20.

20. Howie, I. and V. M. Karbhari . 1995. "Effect of Two Sheet Composite Wrap Architecture on Strengthening of Concrete due to Confinement: I - Experimental Studies," Journal of Reinforced Plastics and Composites, 14(9):1008-1030.

21.

21. Kupfer, H. , H. K. Hilsdorf and H. Rusch . 1969. "Behavior of Concrete under Biaxial Stresses," American Concrete Institute Journal, 66:656-666.

22.

22. Lahlou, K. , P. C. Aitcin and O. Chaallal . 1992. "Behavior of High Strength Concrete under Confined Stresses," Cement and Concrete Composites, 14(3):185-193.