New Strengthening Technique Using FRP to Improve the Confinement Effectiveness of the Rectangular Columns

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In this study, new technique is proposed to improve the confinement effect of the rectangular columns confined with carbon fiber reinforced polymers (CFRP) wraps. In this technique, rectangular column cross-section is divided into nearly square parts at places of CFRP wrapping by drilling slots throughout the long side of the column. The slots allow the CFRP strips to wrap around and confined nearly square parts and then filled with epoxy paste and so increasing the effective confined area of the column cross-section. An experimental program was performed to examine the proposed wrapping technique. The research examines the effect of dividing the rectangular column cross section to two squares, the effect of number of CFRP wrapping layers (i.e., CFRP thickness), and the width of each layer. The experimental results indicate that dividing the rectangular cross section to squares increase the axial column capacity. Also, using the same amount of CFRP, increasing the CFRP strips width has greater effect on increasing the ultimate load capacity rather than decreasing the width with increasing the thickness.
An analytical model, conducted on rectangular columns confined by CFRP and verified using the test results, gave good agreement with the experimental results

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Rectangular Column; Confined Concrete; CFRP; Confinement

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Amir Mirmiran and Mohsen Shahawy, Behavior of Concrete Columns Confined By Fiber Composites, Journal of Structural Engineering, ASCE, Vol. 123,No.5, May 1997, pp.583-590.

Amir Mirmiran , Mohsen Shahawy, Michel Sammaan , Hazem EL Echary, Juan Carlos Mastrapa and Odell Pico, “ Effect of Column Parameters on FRP-Confined Concrete, ”Journal of Composites for construction, ASCE, Vol 2,No.4, Nov. 1998, pp.175-185.

De Luca, A., Nardone, F., Matta, F., Nanni, A., Lignola, G., and Prota, A., ”Structural Evaluation of Full-Scale FRP-Confined Reinforced Concrete Columns.” Journal of Composites for construction, ASCE, Vol 15,No.1, Feb 2011, pp.112-123.

Anupam Chakrabarti ” Confinment Behaviour of Eccentrically Loaded RCC Columns using FRP Sheets ” 5th International Conference on FRP Composites in Civil Engineering (CICE 2010), Sept. 2010 Beijing, China.

Abdelhady Hosny,Hamdy Shahin,Amr Abdelrahman and Tamer El-Afandy, ” Uniaxial Tests on Rectangular Columns Strengthened With CFRP ” Proceedings of Structural Composites For Infrastructure Applications Conference, Aswan, Egypt, 2002.

Adel El-Kurdi, Shafik Khoury, Aly Eldarwish, Ahmed Khalifa, , and Alaa Morsy ” Behaviour of Axially Loaded Columns Strengthened with Carbon Fiber Reinforced Polmers ” , 5th International Alexandria International Conference on Structural and Geotechnical Engineering, AISCGE 5, Faculty of Engineering, Alexandria University, December 2003, pp. MT 351-370.

Lei-Ming Wang, Yu-Fei Wu, ” Effect of Corner Radius on the Performance of CFRP Confined Square Concrete Columns, ”Journal of Engineering Structures, Elsevier LTD, Vol 30,Issue 2, February 2008, pp.493-505.

El-Tony M. El-Tony, Mohamed El-Naggar, Alaa M. Morsy, Effect of Tie Configurations on the Performances of R.C. Columns under Lateral and Vertical Loads, (2013) International Review of Civil Engineering (IRECE), 4 (1), pp. 1-6.

Yu-Fei Wu and You-Yi Wei, ” Effect of Cross-Sectional Aspect Ratio on the Strength of CFRP-Confined Rectangular Concrete Columns,”Journal of Engineering Structures, Elsevier LTD, Vol 32,Issue 1, January 2010, pp.32-45.

Tan Kiang Hwee and Tamali Bhowmik, ” Enhancement of Axial Load Capacity of Capsule-Shaped Columns With Carbon FRP System”, The 3 rd International Conference –Asian Concrete Federation (ACF), November 2008.

Yan, Z., and Pantelides, C. P, ”External FRP Confinement of Concrete Columns Using Shape Modification Technology”, Fourth International Conference on FRP Composites in Civil Engineering (CICE2008), Zurich, Switzerland, July 22-24 2008, paper 1.A.4.

Sika Corporation, ” Engineering Guidelines for the use of SikaCarbodur (CFRP) laminates for structural strengthening of concrete”, 1st English Ed., Sika Corporation, Lyndhurst, NJ, 1997.

Aly Eldarwish, Ahmed Khalifa, Shafik Khoury, Adel El-Kurdi, and Alaa Morsy, ”Analytical Model For Axially Loaded Rectangular reinforced concrete Columns confined by Fiber Reinforced Polymer Jackets" , 4th International Middel East Symposium on Structural Composies fot Infrastructure Application, MESC-4, Faculty of Engineering, Ain Shams University, May 2005.

Mander, J.B., Priestley, M.J.N., and Park, R., “Observed Stress-train Behavior of Confined Concrete, ”Journal of structural engineering, ASCE, Vol 114,No.8, August 1988, pp.1804-1949.

Omar Chaallal , Mohasen Shahawy and Munzer Hassan , “ Performance of Axially Loaded Short Rectangular Columns Strengthened With Carbon Fiber-Reinforced Polymer Wrapping , ”Journal of Composites for construction, ASCE, Vol 7,No.3, August 2003, pp.200-208.

Yung C. Wang and Jose I. Restrepo, “ Investigation of concentrically loaded reinforced concrete columns confined with Glass Fiber Reinforced Polymers jackets,” ACI Structural Journal, May –June 2001, pp 337-385


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