33 Page 33-46 © MAT Journals 2019. All Rights Reserved Journal of Construction and Building Materials Engineering e-ISSN: 2581-6454 Volume 5 Issue 3 Evaluating the Efficiency of Carbon Fiber Reinforced Polymer (CFRP) in Increasing the Compressive Strength of Circular Concrete Column Md. Hossain Nadim* 1 , Md. Mashfiqul Islam 2 , Saima Mustafiz 3 , Debu Kumar Mitra 3 1 Lecturer, 2 Assistant Professor, 3 UG Student Department of Civil Engineering, Ahsanullah University of Science and Technology, Bangladesh Email: *mhntopon@gmail.com DOI: Abstract Structural elements that have deteriorated or have become operationally ineffective during their lifetime can be retrofitted by using Fiber Reinforced Polymer (FRP). Instead of demolishing existing structures improving them by using FRP is a relatively new technique and its gaining popularity. Various experimental and analytical studies are being undertaken to evaluate the performance of FRP on enhancing the performance of structural elements. In this study axial compression tests are performed on Carbon Fiber Reinforce Polymer (CFRP) wrapped circular column specimen and the efficiency of CFRP to increase the ultimate compressive strengths of the columns specimen compared to the unwrapped specimen are investigated. Concrete composed of stone and brick aggregate and two different dimension variations are introduced and the effects of these parameters on the confining pressure provided by CFRP is also evaluated in this study. Keywords: Carbon fiber reinforce polymer, circular column, compressive strength, stone and brick aggregate INTRODUCTION Improving the operating conditions of deficient or deteriorating structures is becoming a growing concern. Many environmental effects are responsible for the deterioration of structures mainly, corrosion, thermal cracking, freeze-thaw cycles, contact with harmful chemicals and saline water and prolonged exposure to UV- radiations, etc. [1]. Other factors such as gradual loss of strength with ageing, imperfect structural design increase of applied load and damages due to seismic load are also liable for need of improvement of structural elements. Also changes in structural design and safety guidelines may compel the use of structural retrofit technologies. The structural retrofitting process has two methods, i.e., (i) repair and retrofit or (ii) demolition and reconstruction [2]. Due to change in economic and social perspective the former option is gaining more acceptances. Repairing/ retrofitting is a more sustainable solution compared to demolishing and reconstructing due to conservation of resources and less carbon footprint [3]. These circumstances impel the need to prepare suitable retrofit systems to strengthen structures without putting more strain on depleting natural resources and the environment. Historically, the retrofitting of reinforced concrete structural elements was done by removing affected or damaged concrete or