Intermediate Layer Effects in Performance of FRP-Confined RC Columns

مهندسی عمران فردوسی

Article 5, Volume 28, Issue 1 - Serial Number 15, December 2016, Pages 49-64   

Document Type: پژوهشی

DOI: 10.22067/civil.v28i1.35206

Authors

hamid karimizadeh^* ; mohammad reza eftekhar

Isfahan University of Technology

Abstract

The use of polymer composite (FRP) as a reinforcement material for the repair and strengthening of important components of reinforced concrete structures, particularly columns, has found wide spread. In this study, the effect of intermediate layer on improving the confinement behavior of reinforced concrete columns has been investigated. To achieve the objectives of the study, 14 cylindrical reinforced concrete specimens with 150 mm diameter and 500 mm height were tested under pure axial load. The columns have been classified into four groups and were reinforced by one or two layers of carbon fibers and then to investigate the research topic, confinement with intermittent CFRP strips was performed in both traditional (Without intermediate layer) and modern method examined in the present study and the results were compared together and with the results of loading columns with internal reinforcement and without external reinforcement (the control sample). The new method involves using a thin layer of galvanized sheet (thickness 0.13 mm) which is mounted under the FRP sheet to prevent the transmission of stress concentration induced cracking concrete to FRP Sheets.The middle layer reduces the transfer of biaxial stress to FRP sheettoo. The results suggest that specimens reinforced with FRP and galvanized sheets have higher strength and ductility than specimens reinforced with FRP and without Galvanized.

Keywords

RC column, Intermediate layer; Confinement; CFRP Composite; Compressive Strength; Ductility

Supplementary Files

4-karimizade.pdf

References

1. Samaan, M., Mirmiran, A., and Shahawy, M., "Model of Concrete Confined By Fiber Composites", Journal of Structural Engineering, Vol. 124, pp. 1025-1031, (1998).

2. Structures, C., "ACI Committee 440", American Concrete Institute, ACI, Vol., (2008).

3. No, D.M., "ISIS CANADA RESEARCH NETWORK", (2007).

4. Parretti, R., and Nanni, A., "Axial Testing of Concrete Columns Confined with Carbon FRP: Effect of Fiber Orientation", Proceedings. CD Proc. of the third international conference on composites in infrastructure, (2002).

5. Chaallal, O., Shahawy, M., and Hassan, M., "Performance of Axially Loaded Short Rectangular Columns Strengthened with Carbon Fiber-Reinforced Polymer Wrapping", Journal of Composites for Construction, Vol. 7, pp. 200-208, (2003).

6. Theriault, M., Neale, K.W., and Claude, S., "Fiber-Reinforced Polymer-Confined Circular Concrete Columns: Investigation of Size and Slenderness Effects", Journal of Composites for Construction, Vol. 8, pp. 323-331, (2004).

7. Matthys, S., Toutanji, H., and Taerwe, L., "Stress–Strain Behavior of Large-Scale Circular Columns Confined with FRP Composites", Journal of Structural Engineering, Vol. 132, pp. 123-133, (2006).

8. Al-Salloum, Y.A., "Influence of Edge Sharpness on the Strength of Square Concrete Columns Confined with FRP Composite Laminates", Composites Part B: Engineering, Vol. 38, pp. 640-650, (2007).

9. Hadi, M., "Behaviour of FRP Wrapped Normal Strength Concrete Columns Under Eccentric Loading", Composite structures, Vol. 72, pp. 503-511, (2006).

10. Yang, X., Nanni, A., and Chen, G., "Effect of Corner Radius on the Performance of Externally Bonded FRP Reinforcement", Proceedings.5th international. conference. on Non-Metallic Reinforcement for Concrete Structures, (2001).

11. Yang, X., Wei, J., Nanni, A., and Dharani, L.R., "Shape Effect on the Performance of Carbon Fiber Reinforced Polymer Wraps", Journal of Composites for Construction, Vol. 8, pp. 444-451, (2004).

12. Toutanji, H., "Stress-Strain Characteristics of Concrete Columns Externally Confined with Advanced Fiber Composite Sheets", ACI Materials Journal, Vol. 96, (1999).

13. Xiao, Y., and Wu, H., "Compressive Behavior of Concrete Confined by Carbon Fiber Composite Jackets", Journal of Materials in Civil Engineering, Vol. 12, pp. 139-146, (2000).

14. Lam, L., and Teng, J., "Ultimate Condition of Fiber Reinforced Polymer-Confined Concrete", Journal of Composites for Construction, Vol. 8, pp. 539-548, (2004).

15. Cole, C.B., "Performance of FRP-Jacketed Reinforced Concrete Columns Subjected to Uniaxial Compression", Master of Science in Civil Engineering, University of Missouri–Rolla, Rolla, MO, (2001).

16. De Lorenzis, L., and Tepfers, R., "Comparative Study of Models on Confinement of Concrete Cylinders with Fiber-Reinforced Polymer Composites", Journal of Composites for Construction, Vol. 7, pp. 219-237, (2003).

17. Pessiki, S., Harries, K.A., Kestner, J.T., Sause, R., and Ricles, J.M., "Axial Behavior of Reinforced Concrete Columns Confined with FRP Jackets", Journal of Composites for Construction, Vol. 5, pp. 237-245, (2001).

18. Shahawy, M., Mirmiran, A., and Beitelman, T., "Tests and Modeling of Carbon-Wrapped Concrete Columns", Composites Part B: Engineering, Vol. 31, pp. 471-480, (2000).

19. Matthys, S., Taerwe, L., and Audenaert, K., "Tests on Axially Loaded Concrete Columns Confined by Fiber Reinforced Polymer Sheet Wrapping", ACI Special Publication, Vol. 188, (1999).

20. Fraldi, M., Nunziante, L., Carannante, F., Prota, A., Manfredi, G., and Cosenza, E., "On the Prediction of the Collapse Load of Circular Concrete Columns Confined by FRP", Engineering Structures, Vol. 30, pp. 3247-3264, (2008).

21. Fam, A.Z., and Rizkalla, S.H., "Confinement Model for Axially Loaded Concrete Confined by Circular Fiber-Reinforced Polymer Tubes", ACI structural journal, Vol. 98,( 2001).

22. Harries, K.A., and Carey, S.A., "Shape and “Gap” Effects on the Behavior of Variably Confined Concrete", Cement and Concrete Research, Vol. 33, pp. 881-890, (2003).

23. Campione, G., "Influence of FRP Wrapping Techniques on the Compressive Behavior of Concrete Prisms", Cement and concrete composites, Vol. 28, pp. 497-505, (2006).

24. ایلیا، الهه، « بررسی رفتار محوری ستون‌های محوری چهارگوش تقویت‌شده با نوارهای FRP در گوشه‌ها و بست‌های FRP در وجوه»، پایان-نامه کارشناسی ارشد، دانشکده عمران دانشگاه صنعتی اصفهان.(1391)

25. Mirmiran, A., Shahawy, M., Samaan, M., Echary, H.E., Mastrapa, J.C., and Pico, O., "Effect of Column Parameters on FRP-Confined Concrete", Journal of Composites for Construction, Vol. 2,

pp. 175-185, (1998).

26. Rousakis, T. C., Karabinis, A. I., Kiousis, P. D., "FRP-Confined Concrete Members: Axial Compression Experiments and Plasticity Modeling". Engineering Structures, Vol. 29, No. 7, pp. 1343–1353, (2007).

27. Piekarczyk, J., Piekarczyk, W., Blazewicz, S., "Compression Strength of Concrete Cylinders Reinforced with Carbon fiber Laminate", Construction and Building Materials, Vol. 25, pp. 2365-2369, (2011).