Study The Behavior of Square Reinforced Concrete Columns Strengthened with CFRP




reinforcement concrete, square column, polymer CFRP wraps, mechanical and structural features


There is a scarcity of research regarding the efficacy of Fiber Reinforced Polymer (FRP) confinement on low strength materials. This paper presents the findings of an experimental study that focuses on the behavior of concentrically loaded short concrete columns with low concrete strength, which are confined using CFRP wraps. A set of nine (9) square concrete columns of short length were subjected to testing. The experimental setup consisted of a single unconfined column, referred to as the control column, and eight additional columns that were confined utilizing externally bonded CFRP wraps. These confining schemes were determined based on the findings of a previous study conducted by the authors, which focused on short square columns with smaller cross sections. The study focused on examining the impact of various confinement schemes on the load carrying capacities of columns through the application of concentric uniaxial compression. The implementation of various confinement schemes led to an increase in the load carrying capacities of confined concrete columns, demonstrating the effectiveness of externally bonded CFRP wraps in enhancing the performance of short rectangular concentrically loaded concrete columns. The primary objective of this investigation is to examine the behavior of concrete columns with reinforcement that have been reinforced using carbon fiber composites. The findings demonstrated the efficacy of carbon fibers in the restoration of impaired columns, as evidenced by a notable enhancement in the load-bearing capacity of the columns, ranging from 35% to 90%.


Download data is not yet available.


Al-Khafaji, Z.S., Falah, M.W., Shubbar, A.A., Nasr, M.S., Al-Mamoori, S.F., Alkhayyat, A., Al-Rifaie, A., Eissa, A., Al-Mufti, R.L., Hashim, K., 2021. The Impact of Using Different Ratios of Latex Rubber on the Characteristics of Mortars Made with GGBS and Portland Cement. IOP Conference Series: Materials Science and Engineering 1090, 012043. DOI:

Al-Mekhlafi, G.M., Al-Osta, M.A., Sharif, A.M., 2020. Behavior of eccentrically loaded concrete-filled stainless steel tubular stub columns confined by CFRP composites. Engineering Structures 205, 110113. DOI:

Al-Nimry, H., Neqresh, M., 2019. Confinement effects of unidirectional CFRP sheets on axial and bending capacities of square RC columns. Engineering Structures 196, 109329. DOI:

Ali, A.M., Falah, M.W., Hafedh, A.A., Al-Khafaji, Z.S., 2022. Evaluation the influence of steel- fiber on the concrete Characteristics. Periodicals of Engineering and Natural Sciences 10. DOI:

Barros, J.A.O., Varma, R.K., Sena-Cruz, J.M., Azevedo, A.F.M., 2008. Near surface mounted CFRP strips for the flexural strengthening of RC columns: Experimental and numerical research. Engineering Structures 30, 3412–3425. DOI:

Dundar, C., Erturkmen, D., Tokgoz, S., 2015. Studies on carbon fiber polymer confined slender plain and steel fiber reinforced concrete columns. Engineering structures 102, 31–39. DOI:

El Maaddawy, T., 2009. Strengthening of eccentrically loaded reinforced concrete columns with fiber-reinforced polymer wrapping system: Experimental investigation and analytical modeling. J. Compos. Constr 13, 13–24.

Falah, M., Al-khafaji, Z., 2022. Behaviour Of Reactive Powder Concrete Hollow Core Columns Strengthened with Carbon Fiber Reinforced Polymer Under Eccentric Loading. Electronic Journal of Structural Engineering 22, 28–38. DOI:

Falah, M W, Al-Khafaji, Z.S., Yaseen, R., Yousif, D.F., Hamza, K.A., Radhi, S.S., 2022. Finite element simulations for the sustainable CFRP retrofitted hollow square columns. Electronic Journal of Structural Engineering 22, 1–13. DOI:

Falah, M.W., Al-Khafaji, Z.S., Yaseen, R., Yousif, D.F., Hamza, K.A., Radhi6, S.S., 2022. Finite Element Simulations of the CFRP Retrofitted Hollow Square Columns. Electronic Journal of structural Engineering.

Falah, M.W., Ali, Y.A., Al-Mulali, M.Z., Al-Khafaji, Z.S., 2020. Finite Element Analysis Of CFRP Effects On Hollow Reactive Powder Concrete Column Failure Under Different Loading Eccentricity. Solid State Technology 63.

Huang, Z., Shen, J., Lin, H., Song, X., Yao, Y., 2020. Shear behavior of concrete shear walls with CFRP grids under lateral cyclic loading. Engineering Structures 211, 110422. DOI:

Hussain, M.A., Driver, R.G., 2005. Experimental investigation of external confinement of reinforced concrete columns by hollow structural section collars. ACI Structural Journal 102, 242. DOI:

IQS, 1984. No. 45, Aggregate from natural sources for concrete and construction. Iraqi Specif.

Iraqi Specification No.5 -1984, second modify 2010, 2010. Portland cement.

Karam, G., Tabbara, M., 2005. Confinement effectiveness in rectangular concrete columns with fiber reinforced polymer wraps. Journal of composites for construction 9, 388–396. DOI:

Lam, L., Teng, J.G., 2003. Design-oriented stress-strain model for FRP-confined concrete in rectangular columns. Journal of reinforced plastics and composites 22, 1149–1186. DOI:

Maaddawy, T. El, 2009. Strengthening of eccentrically loaded reinforced concrete columns with fiber-reinforced polymer wrapping system: Experimental investigation and analytical modeling. Journal of Composites for Construction 13, 13–24. DOI:

Mirmiran, A., Shahawy, M., Samaan, M., Echary, H.E.L., Mastrapa, J.C., Pico, O., 1998. Effect of column parameters on FRP-confined concrete. Journal of Composites for construction 2, 175–185. DOI:

Parvin, A., Wang, W., 2001. The behavior of FRP jacketed concrete columns under eccentric loading. Journal of Composites for construction 5, 146–152. DOI:

Punurai, W., Hsu, C.-T.T., Punurai, S., Chen, J., 2013. Biaxially loaded RC slender columns strengthened by CFRP composite fabrics. Engineering Structures 46, 311–321. DOI:

Rochette, P., Labossiere, P., 2000. Axial testing of rectangular column models confined with composites. Journal of composites for construction 4, 129–136. DOI:

Saljoughian, A., Mostofinejad, D., 2018. Grooving methods in square RC columns strengthened with longitudinal CFRP under cyclic axial compression. Engineering Structures 174, 724–735. DOI:

Samaan, M., Mirmiran, A., Shahawy, M., 1998. Model of concrete confined by fiber composites. Journal of structural engineering 124, 1025–1031. DOI:

Sayed-Ahmed, E.Y., Shaat, A.A., Abdallah, E.A., 2018. CFRP-strengthened HSS columns subject to eccentric loading. Journal of Composites for Construction 22, 4018025. DOI:

ViscoCrete®-5930, S., 2010. High Performance Superplasticiser Concrete Admixture. Product data sheet. Edition 6.

Wang, Y.-C., Hsu, K., 2008. Design of FRP-wrapped reinforced concrete columns for enhancing axial load carrying capacity. Composite structures 82, 132–139. DOI:

Wang, Z., Wang, D., Smith, S.T., Lu, D., 2012. CFRP-confined square RC columns. I: Experimental investigation. Journal of Composites for Construction 16, 150–160. DOI:

Wei, H., Wu, Z., Guo, X., Yi, F., 2009. Experimental study on partially deteriorated strength concrete columns confined with CFRP. Engineering Structures 31, 2495–2505. DOI:

Xu, T., Liu, J., Wang, X., Guo, Y., Chen, Y.F., 2020. Behaviour of short CFRP-steel composite tubed reinforced normal and high strength concrete columns under eccentric compression. Engineering Structures 205, 110096. DOI:

Yan, Z., Pantelides, C.P., Reaveley, L.D., 2006. Fiber-reinforced polymer jacketed and shape-modified compression members: I-experimental behavior. ACI structural journal 103, 885. DOI:




How to Cite

Al-Khafaji, Z. (2023) “Study The Behavior of Square Reinforced Concrete Columns Strengthened with CFRP”, Electronic Journal of Structural Engineering, 23(4), pp. 79–84. doi: 10.56748/ejse.23487.