Behavior of Columns Confined With FRP Fabrics under Repeated Lateral Loads

Main Article Content

Hesham A. Haggag
Nagy F. Hanna
Ghada G. Ahmed

Abstract

The axial strength of reinforced concrete columns is enhanced by wrapping them with Fiber Reinforced Polymers, FRP, fabrics.  The efficiency of such enhancement is investigated for columns when they are subjected to repeated lateral loads accompanied with their axial loading.  The current research presents that investigation for Glass and Carbon Fiber Reinforced Polymers (GFRP and CFRP) strengthening as well.  The reduction of axial loading capacity due to repeated loads is evaluated. The number of applied FRP plies with different types (GFRP or CFRP) are considered as parameters in our study. The study is evaluated experimentally and numerically.  The numerical investigation is done using ANSYS software. The experimental testing are done on five half scale reinforced concrete columns.  The loads are applied into three stages. Axial load are applied on specimen in stage 1 with a value of 30% of the ultimate column capacity. In stage 2, the lateral loads are applied in repeated manner in the existence of the vertical loads.  In the last stage the axial load is continued till the failure of the columns. The final axial capacities after applying the lateral action, mode of failure, crack patterns and lateral displacements are recorded.   Analytical comparisons for the analyzed specimens with the experimental findings are done.  It is found that the repeated lateral loads decrease the axial capacity of the columns with a ratio of about (38%-50%).  The carbon fiber achieved less reduction in the column axial capacity than the glass fiber.  The column confinement increases the ductility of the columns under the lateral loads.

Keywords:
Axial strength, confined columns, GFRP, CFRP, repeated lateral load, ANSYS.

Article Details

How to Cite
Haggag, H. A., Hanna, N. F., & Ahmed, G. G. (2019). Behavior of Columns Confined With FRP Fabrics under Repeated Lateral Loads. Journal of Engineering Research and Reports, 6(4), 1-19. Retrieved from http://journaljerr.com/index.php/JERR/article/view/16954
Section
Original Research Article

References

Shuenn-Yih Chang, Ting-Wei Chen, Ngoc-Cuong Tran, Wen-I Liao. Seismic retrofitting of RC columns with RC jackets and wing walls with different structural details, Earthquake Engineering and Engineering Vibration. 2014;13(2).

Hamidreza Nasersaeed. Evaluation of behavior and seismic retrofitting of RC structures by concrete jacket, Asian Journal of Applied Sciences; 2011.

Yeou-Fong Li, Jenn-Shin Hwang. A study of reinforced concrete bridge columns retrofitted by steel jackets, Journal of the Chinese Institute of Engineers. 2005;28(2).

Wang JH, Kikuchi K, Kuroki M. Seismic retrofit of existing R/C rectangular columns with circular steel jackets, 30th Conference on Our World in Concrete & Structures, Singapore; 2005.

Guo ZX, Liu Y, Wu YB. Experimental study on a new retrofitted scheme for seismically deficient RC columns, The 14th World Conference on Earthquake Engineering, Beijing, China; 2008.

Muhammad S. Memon, Shamim A. Sheikh. Seismic resistance of square concrete columns retrofitted with glass fiber-reinforced polymer. ACI Structural Journal; 2005.

Stathis N. Bousias, Michael N. Fardis. Experimental research on vulnerability and retrofitting of old-type RC columns under cyclic loading, Springer; 2003.

Hamid Saadatmanesh, Mohammad R. Ehsani, Limin. Repair of Earthquake-damaged RC columns with FRP wraps, ACI Structural Journal; 1997.

Mesay A. Endeshaw, Mohamed ElGawady, Ronald L. Sack, David I. McLean. Retrofit of rectangular bridge columns using CFRP wrapping Washington State Transportation Center (TRAC) - Washington State University - Department of Civil & Environmental Engineering; 2008.

Yan Z, Pantelides CP, Reaveley LD. Seismic retrofit of bridge columns using fiber reinforced polymer composite shells and shape modification, The 14th World Conference on Earthquake Engineering; 2008.

Brian J. Walkenhauer, David I. McLean. Seismic retrofit of cruciform-shaped columns in the aurora avenue bridge using FRP wrapping, Washington State University – Department of Civil & Environmental Engineering; 2010.

Gnanasekaran, Amlan. Seismic retrofit of columns in buildings for flexure using concrete jacket, ISET Journal of Earthquake Technology, 2009;46(2):505.