Civil Engineering and Architecture 9(5A): 86-92, 2021 http://www.hrpub.org DOI: 10.13189/cea.2021.091310 Experimental Investigation on Acoustic Emission Characteristics of Reinforced Concrete Beam Strengthened with CFRP Soffian Noor Mat Saliah 1 , Noorsuhada Md Nor 1,* , Khairul Nizam K. 1 , Muhammad Ariffaizad M.M. 1 , Mohd Subri Tahir 2 1 School of Civil Engineering, College of Engineering, Universiti Teknologi MARA, Cawangan Pulau Pinang, Pulau Pinang, Malaysia 2 Department of Business Management, Universiti Teknologi MARA, Cawangan Pulau Pinang, Malaysia Received October 16, 2020; Revised July 27, 2021; Accepted August 9, 2021 Cite This Paper in the following Citation Styles (a): [1] Soffian Noor Mat Saliah, Noorsuhada Md Nor, Khairul Nizam K., Muhammad Ariffaizad M.M., Mohd Subri Tahir , "Experimental Investigation on Acoustic Emission Characteristics of Reinforced Concrete Beam Strengthened with CFRP," Civil Engineering and Architecture, Vol. 9, No. 5A, pp. 86 - 92, 2021. DOI: 10.13189/cea.2021.091310. (b): Soffian Noor Mat Saliah, Noorsuhada Md Nor, Khairul Nizam K., Muhammad Ariffaizad M.M., Mohd Subri Tahir (2021). Experimental Investigation on Acoustic Emission Characteristics of Reinforced Concrete Beam Strengthened with CFRP. Civil Engineering and Architecture, 9(5A), 86 - 92. DOI: 10.13189/cea.2021.091310. Copyright©2021 by authors, all rights reserved. Authors agree that this article remains permanently open access under the terms of the Creative Commons Attribution License 4.0 International License Abstract Reinforced concrete (RC) structures are generally subjected to increasing loads, age-related deterioration and design changes that affect the integrity of structures. Therefore, this paper presents an experimental investigation of a carbon fibre reinforced polymer (CFRP) reinforced RC beam under three-point loading. Acoustic emission (AE) was used to monitor the progression of damage. The loading, AE intensity and AE signal strength were analysed and discussed. The analyses were performed using the AE signal collected from CH6 and CH7. The result is that crack nucleation produces high signal intensity compared to other crack modes. Moreover, the intensity plots fit the identified crack modes when the beams were reinforced with CFRP. Therefore, AE can be used to evaluate the performance of the CFRP reinforced RC beam. Keywords Acoustic Emission, Carbon Fibre Reinforced Polymer, Intensity Analysis, Strengthening 1. Introduction Reinforced concrete (RC) is the most popular material used in construction industry all over the world. A major concern related to structure RC is the risk of deterioration due to ageing factors, changes in design, construction errors, or increasing load. Deterioration reduces the strength and integrity of RC structures. Much research has been conducted to reduce the deterioration of RC structure by reinforcing the structure with fibre reinforced polymer (FRP) laminates, such as carbon fibre reinforced polymer (CFRP). CFRP has been used to reinforce RC structures such as concrete arches [1], beam-column connections [2 - 4], beams [5 - 6], slabs [7 - 8] and columns [9]. Most researches have shown that the CFRP can increase the strength of RC structure. At the same time, the integrity of RC structure can be maintained even after failure [7]. The integrity of the CFRP reinforced structure RC is also related to the bonding and surface preparation of the concrete. Therefore, the bond and the effect of CFRP laminate on concrete surface were studied by Noorsuhada et al. [10]. They found that the type of surface preparation also affects the adhesion between the two materials in terms of tear strength. Although bonding plays an important role in the integrity of the concrete structure, a thorough investigation of the concrete structure reinforced with CFRP is also essential. Most evaluations have been performed by visual observation, which is one of the nondestructive testing (NDT) methods. It is the simplest and least expensive