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Submitted
December 22, 2025
Accepted
March 25, 2026
Published
June 1, 2026
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Abstract

This research examines the performance of geopolymer paste compared with epoxy adhesive for flexural strengthening of RC beams. Five beam specimens were cast with dimensions of 130 x 160 x 1300 mm. One specimen was non-strengthened and served as a reference beam, while four beams were strengthened using the near-surface-mounted (NSM) method. The strengthened samples included either a single groove or a double groove. Geopolymer paste and epoxy paste were employed as adhesive materials in this paper. Additionally, the NSM -bar reinforcement consisted of a steel bar with a diameter of 8 mm. The study parameters were the number. of grooves and the adhesive material. type. All RC beam specimens were tested under a four-point loading. The ultimate load capacity, load-deflection behavior, initial crack load, and mode of failure of the RC beam were analyzed. This study aims to investigate the influence of geopolymer adhesive on the flexural strengthening of RC beams using the NSM technique. In general, the findings demonstrate that the ultimate load of strengthened specimens with two grooves increased in initial crack load and load bearing capacity by 64.29% and 71.87 %, respectively, in contrast to an un-strengthened beam (control beam).


     

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Copyright (c) 2026 The Author(s), under exclusive license to the University of Thi-Qar. UTJES is an open-access journal where all contents are free of charge. Articles of this journal are licensed under the terms of the Creative commons Attribution 4.0 International License Creative Commons-Attribution (CC BY 4.0) that licensees are unrestrictedly allowed to search, download, share, distribute, print, or link to the full texts of the articles, crawl them for indexing and reproduce any medium of the articles provided that they give the author(s) proper credits (citation). The authors hold the copyright for their published work on UTJES website, while UTJES is responsible for appreciating citation for their work, which is released under CC-BY-4.0 enabling the unrestricted use, distribution, and reproduction of an article in any medium, provided that the original work is properly cited.

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