This  paper  aims  to  introduce  the  content  of  Annex  J  “Strengthening  of  Existing  Concrete  Structures with CFRP” of Eurocode 2 [1]. This is first time that the design of adhesively bonded reinforcement  with  CFRP  has  been  introduced  in  the  European  regulations  through  an  informative annex. Annex J considers two different bonded strengthening techniques: externally bonded reinforcement (EBR) that consists of bonding CFRP strips or sheets to the surface of concrete elements, and near surface mounted reinforcement (NSM) that consists of embedded CFRP strips or rods to the slot cut in the concrete cover. Since, the content of Annex J is new, a summary  and  background  related  to  all  aspects  required  for  designing  CFRP  strengthened  systems for concrete structures, are given in this paper., The authors acknowledge the support provided by Spanish Ministry of Science and Innovation (MCIN/AEI) and by the European Funds for Regional Development in the following projects during their collaboration in the CTN140/SC2 and in the CEN/TC250/SC2/WG1/TG1 (Eva Oller): BIA2015‐64672‐C4‐1‐R, RTI2018‐097314‐B‐C21, and PID2020‐119015GB‐C22., Peer Reviewed, Postprint (published version)

This paper presents an experimental work to investigate the effect of fatigue loading and high service temperature on the flexural performance of near-surface mounted (NSM) carbon fiber reinforced polymer (CFRP)-strengthened reinforced concrete (RC) beams. The experimental program included 11 beams, where the effect of the strengthening (CFRP) ratio (0.06 % and 0.18 %), fatigue load level (R1 = 0.57 and R2 = 0.38) and applied temperature (20 °C and 70 °C) have been considered. Experimental results on fatigue tests showed that high service temperature resulted in an increase in deflections and reduction in the stiffness of the specimens along the test. Moreover, the application of fatigue cycles with larger amplitude resulted in the failure of the specimens (by steel rupture), whilst specimens submitted to lower fatigue amplitude survived to the fatigue cycles. The NSM CFRP-strengthening helped to postpone the final failure of strengthened RC beams after steel reinforcement rupture during the fatigue test. Besides, damage due to fatigue derived in lower residual yielding and ultimate load in the post-fatigue test, This research was supported by the Spanish Ministry of Science and Innovation (MCIN/ AEI) under project PID2020-119015GB-C22, the Generalitat de Catalunya under the grant number 2019FI_B 00054 and mobility grant from Universitat de Girona (MOB 2021)

Structural repair and strengthening have always been challenging tasks in construction. One of the most commonly applied techniques for Reinforced Concrete (RC) structures is the Externally Bonded Reinforcement (EBR). However, a persistent challenge with EBR is the premature debonding of FRP laminates from the concrete surface. In response, researchers have explored alternative techniques to improve this issue, leading to techniques such as Near-Surface Mounted (NSM) reinforcement, Externally Bonded Reinforcement on Grooves (EBROG), Externally Bonded Reinforcement in Grooves (EBRIG), and the use of mechanical fasteners. This study introduces and evaluates a new strengthening technique designed to enhance the conventional EBR approach while requiring minimal alterations to surface preparation, saving both time and costs. The proposed technique, presented as Externally Bonded Reinforcement Side Extended (EBRSE), involves applying resin to both lateral sides of the precured laminate parallel to the loading direction. In this work, single shear tests were conducted on concrete specimens using both EBRSE and conventional EBR techniques to compare their performance. Additionally, a numerical approach was applied, combining the finite difference method with a metaheuristic optimization algorithm, to derive the bond-slip law governing the constitutive behavior of both systems. The findings revealed that the EBRSE technique significantly outperformed the conventional EBR method, with an increase of up to 80 % in ultimate load capacity and up to 86 % in ultimate slip. Furthermore, the comparison between numerical predictions and experimental findings, specifically in terms of bond-slip law, load-slip curves, and strain distribution along the bonded FRP, confirmed an increase in fracture energy for the EBRSE technique, The authors acknowledge the support provided by the Spanish Ministry of Science, Innovation and Universities (MICIU/ AEI) through projects PID2020–119015GB-C22/MICIU/AEI/10.13039/501100011033 and PID2023–150934NB-C32/MICIU/AEI/10.13039/501100011033/FEDER, UE; M.A. acknowledges the support of University of Girona through research grant IFUdG 2021/01 cofunded by Banco Santander; L.C. acknowledges the grant RYC2021–032171-I funded by MCIN/AEI/ 10.13039/501100011033 and by “European Union NextGenerationEU/PRTR

The use of fiber reinforced polymer (FRP) for flexural strengthening of reinforced concrete (RC) beams has become a popular strengthening technique. Significant amount of work is available on the short-term flexural behavior of RC beams strengthened with near-surface mounted (NSM) technique. However, their time-dependent flexural behavior, specifically under high service temperature, has not yet been addressed. This paper presents an experimental work to evaluate the time-dependent behavior of NSM carbon FRP (CFRP)-strengthened RC beams. The experimental program included 23 beams, where the effect of different parameters such as strengthening (CFRP) area, steel reinforcement ratio and applied temperature (20 and 50 °C) have been considered. Experimental results show that the effect of strengthening area is significant on the flexural short-term response of the beams, while minor effects are found on the time-dependent deflections. On the other hand, increasing the service temperature has no significant effect on the short-term tests, but it produces a large increase in the time-dependent deflection of the specimens. Finally, an analytical procedure for the prediction of time-dependent deflections, which is based on the age-adjusted effective modulus method (AEMM), is presented. Good agreement between the experimental results and analytical predictions on time-dependent deflections is shown, This research was supported by the Spanish Ministry of Science and Innovation (MCIN/ AEI) under project PID2020-119015GB-C22 and the Generalitat de Catalunya (under the grant numbers: 2019FI_B 00054 and 2020_FISDU 00476), Open Access funding provided thanks to the CRUE-CSIC agreement with Elsevier

The new version of Eurocode 2 will include for the first time an informative annex, Annex R “Embedded FRP reinforcement”, to design reinforced concrete structures with fibre reinforced polymer (FRP) reinforcement. FRP embedded reinforcement has some advantages such as their low susceptibility to corrosion, high-strength, and low life-cycle cost. FRP rebars can be used as longitudinal or transverse reinforcement in a similar way than conventional steel rebars. However, in the design of FRP reinforced concrete structures, some particular aspects related to the reinforcement properties must be taken into account, among which it is worth highlighting their linear elastic behaviour until failure, their relatively low modulus of elasticity or their behaviour under sustained stresses. Since, the content of Annex R is new, a summary and background related to all aspects required for designing with FRP reinforcement are given in this paper., The authors acknowledge the support provided by Spanish Ministry of Science and Innovation (MCIN/  AEI)  and  by  the  European  Funds  for  Regional  Development  in  the  following  projects  during their collaboration in the TN140/SC2 and in the CEN/TC250/SC2/WG1/TG1 (Eva Oller): BIA2015‐64672‐C4‐1‐R, RTI2018‐097314‐B‐C21, and PID2020‐119015GB‐C22., Peer Reviewed, Postprint (published version)

With the assessment of intermediate crack debonding (ICD) being a subject of main importance in the design of reinforced concrete (RC) beams strengthened in flexure with externally bonded fibre-reinforced polymer (FRP), several approaches to predict the debonding loads have been developed in recent decades considering different models and strategies. This study presents an analysis of formulations with different levels of approximation collected in the fib Bulletin 90 regarding this failure mode, comparing the theoretical predictions with experimental results. The carried-out experiments consisted of three RC beams strengthened with carbon FRP (CFRP) tested under a four-point bending configuration with different concrete strengths and internal steel reinforcement ratios. With failure after steel yielding, higher concrete strength, as well as a higher reinforcement ratio, lead to a higher bending capacity. In addition, the performance of the models is assessed through the experimental-to-predicted failure load ratios from an experimental database of 65 RC beams strengthened with CFRP gathered from the literature. The results of the comparative study show that the intermediate crack debonding failure mode is well predicted by all models with a mean experimental-to-predicted failure load ratio between 0.96 and 1.10 in beams tested under three- or four-point bending configurations, This research was funded by the Spanish Ministry of Science and Innovation (MCIN/AEI) under project PID2020-119015GB-C22 and the Generalitat de Catalunya, under the Grant number 2020_FISDU 00476

The new version of Eurocode 2 will include for the first time an informative annex, Annex R “Embedded FRP reinforcement”, to design reinforced concrete structures with fibre reinforced polymer (FRP) reinforcement. FRP embedded reinforcement has some advantages such as their low susceptibility to corrosion, high-strength, and low life-cycle cost. FRP rebars can be used as longitudinal or transverse reinforcement in a similar way than conventional steel rebars. However, in the design of FRP reinforced concrete structures, some particular aspects related to the reinforcement properties must be taken into account, among which it is worth highlighting their linear elastic behaviour until failure, their relatively low modulus of elasticity or their behaviour under sustained stresses. Since, the content of Annex R is new, a summary and background related to all aspects required for designing with FRP reinforcement are given in this paper., Spanish Ministry of Science and Innovation (MCIN/ AEI) and by the European Funds for Regional Development, Peer reviewed

A regulatory framework is required to ensure the correct design of Fibre-Reinforced Polymers (FRPs) increasingly being used as an externally-bonded strengthening system on concrete columns. Several design guidelines on the confinement of FRP concrete have been developed over the past few years worldwide, each proposing a different approach, resulting in different predictions. This study aims to evaluate and compare nine international design guidelines used to predict the compressive strength of confined concrete in FRP-strengthened concrete columns and weigh them against experimental results. The results of this investigation reveal that the predictions from the guidelines on the compressive strengthening of FRP-confined concrete are generally suitable for circular columns, with the ACI-440 and CNR-DT 200 guideline predictions being two of the most accurate. Nevertheless, the guidelines generally tend to overestimate the load-carrying capacity for the compressive strength of FRP-confined concrete in non-circular columns, for which further experimental work using large-scale specimens is required.

The aerospace industry is being driven toward ever-thinner, lighter composite structures, yet traditional balanced-symmetric “Quad” laminates are only able to meet stiffness and damage-tolerance targets by stacking large sublaminates of unidirectional plies—an approach that results in increased thickness, mass, and cost. An alternative architecture—Tailored Antisymmetric Composite (TAC) laminates—is introduced, comprising repeated antisymmetric sublaminates whose fiber orientations are optimized to minimize extension–bending coupling while satisfying stiffness and strength requirements. The feasible design space of TAC sublaminates is comprehensively mapped using lamination parameter plots; despite their minimal ply counts, TAC configurations span nearly the entire lamination-parameter domain—a coverage unattainable by Quad laminates. A genetic-algorithm (GA) framework for replacing Quad laminates with TAC designs is then detailed, and hard, soft, and neutral tapering schemes are compared using classical laminated-plate theory. Strategic tapering of ultra-thin TAC sublaminates is shown to yield 16–25 % weight savings relative to Quad laminates. The results of an experimental validation campaign are presented to quantify post-cure warpage in TAC and Quad plates and to evaluate extension–bending coupling behavior. TAC laminates are shown to sustain warpage levels comparable to those of Quad controls while exhibiting reduced coupling in ultra-thin sections. Moreover, an analytical investigation of bending–twisting coupling is provided. Overall, TAC laminates are presented as a weight-efficient route to next-generation ultra-thin composites, and the methodology laid herein establishes a foundation for future studies. The limitations of the present approach are discussed, and key next steps are outlined.

Orthotropic laminates are highly desirable in composite structures because they eliminate bending–twisting coupling, simplify structural behavior, improve analytical predictability, and facilitate structural design, optimization, and certification. However, achieving fully orthotropic behavior in laminated composites remains challenging because conventional laminate architectures generally retain stiffness couplings arising from anisotropic ply orientations and stacking-sequence effects. This work introduces the Tailored Antisymmetric Composite (TAC) concept, a laminate architecture that provides the closest practical approximation to full orthotropy while preserving broad stiffness-tailoring capability and manufacturability. TAC laminates are constructed from tailored antisymmetric sublaminates that enforce D16=D26=0 while maintaining extremely small extension–bending coupling terms B16 and B26. Representative TAC and symmetric Quad laminates were compared analytically, statistically, and experimentally. Monte Carlo simulations comprising 100,000 realizations with realistic ±0.1° AFP/ATL fiber-orientation deviations showed that the distributions of the extension–bending coupling terms B16*  and B26 * remained nearly indistinguishable for both laminate architectures, with probability-density overlap coefficients between 0.87 and 0.98. In contrast, the bending–twisting coupling terms D16* and D26*  were 140–600 times lower in TAC laminates than in the corresponding Quad laminates, and their statistical distributions exhibited complete separation. Experimental measurements of post-cure warpage confirmed that TAC laminates achieved dimensional stability comparable to symmetric Quad laminates while exhibiting lower variability. These results demonstrate that TAC laminates combine exact elimination of bending–twisting coupling with negligible extension–bending coupling, statistical robustness to realistic manufacturing variability, and excellent dimensional stability, establishing TAC as a practical and systematic route toward full orthotropy in laminated composite structures.

<p>Descripción del proyecto</p>
<p></p>
<p>Monitorización de estructuras de hormigón armado reforzadas con FRP mediante técnicas de inteligencia artificial</p>
<p></p>
<p>4. Descripción del dataset</p>
<p>Se trata de datos de impedancias electromecánica de dos de las probetas que se han ensayado durante el proyecto.</p>
<p></p>
<p>Los datos de la primera probeta (PROBETA1) se componen de diez ficheros en formato excel. La descripción detallada del ensayo y la colocación de los sensores se encuentra en las siguientes publicaciones:</p>
<p></p>
<p>RICARDO PERERA , CONSUELO HUERTA, MARTA BAENA, CRISTINA BARRIS</p>
<p>ANALYSIS OF FRP STRENGTHENED REINFORCED CONCRETE BEAMS USING ELECTROMECHANICAL IMPEDANCE TECHNIQUE AND DIGITAL IMAGE CORRELATION SYSTEM </p>
<p>Sensors </p>
<p>2023, 23, 8933. </p>
<p>https://doi.org/10.3390/s23218933</p>
<p>RICARDO PERERA, JAVIER MONTES, ALEJANDRA GÓMEZ, CRISTINA BARRIS, MARTA BAENA</p>
<p>UNSUPERVISED AUTOENCODERS WITH FEATURES IN THE ELECTROMECHANICAL IMPEDANCE DOMAIN FOR EARLY DAMAGE ASSESSMENT IN FRP-STRENGTHENED CONCRETE ELEMENTS</p>
<p>Engineering Structures</p>
<p>2024, 315, 118458</p>
<p>https://doi.org/10.1016/j.engstruct.2024.118458</p>
<p>Los datos de la segunda probeta (PROBETA2) se componen de diez ficheros excel. La descripción detallada del ensayo y la colocación de los sensores se encuentra en las siguientes publicaciones:</p>
<p>RICARDO PERERA , CONSUELO HUERTA, MARTA BAENA, CRISTINA BARRIS</p>
<p>ANALYSIS OF FRP STRENGTHENED REINFORCED CONCRETE BEAMS USING ELECTROMECHANICAL IMPEDANCE TECHNIQUE AND DIGITAL IMAGE CORRELATION SYSTEM </p>
<p>Sensors </p>
<p>2023, 23, 8933. </p>
<p>https://doi.org/10.3390/s23218933</p>
<p>JAVIER MONTES, JUAN PÉREZ, RICARDO PERERA</p>
<p>DAMAGE INDICATORS FOR STRUCTURAL MONITORING OF FIBER-REINFORCED POLYMER-STRENGTHENED CONCRETE STRUCTURES BASED ON MANIFOLD INVARIANCE DEFINED ON LATENT SPACE OF DEEP AUTOENCODERS</p>
<p>Applied Sciences</p>
<p>2025, 15(11), 5897</p>
<p>https://doi.org/10.3390/app15115897</p>
<p>-</p>
<p>FICHEROS</p>
<p>-</p>
<p>1. Ficheros (Relación de todos los ficheros que se incluyen en el dataset, estructura breve descripción de su contenido, indicar formato, idioma, versión, etc.) </p>
<p>PROBETA 1: Diez ficheros en formato excel, de ENSAYO 1 a ENSAYO 10. Cada fichero representa un estado de carga distinto para todos los sensores analizados. Una descripción detallada se encuentra en los artículos reseñados</p>
<p>PROBETA 2: Diez ficheros en formato excel, de ENSAYO 1 a ENSAYO 10. Cada fichero representa un estado de carga distinto para todos los sensores analizados. Una descripción detallada se encuentra en los artículos reseñados</p>

This paper presents the development of a robust automatic diagnosis technique that uses raw Electro-Mechanical Impedance (EMI) signals and deep autoencoder models to detect damage in fiber-reinforced-polymers (FRP) strengthened reinforced concrete (RC) elements, for which the most common failure modes occur in a sudden and brittle way by debonding. The contribution of this work is threefold: First, for the first time, two autoencoder models, convolutional and fully connected, based on an unsupervised learning framework supplemented by appropriate pre-processing techniques, are proposed for effective tracking of FRP-strengthened RC elements from raw EMI response variations in different locations of the auscultated structure; their implementation is also extensively investigated. The proposed framework consists of two main components, namely, dimensionality reduction and relationship learning. The first component is to reduce the dimensionality of the raw EMI signal while preserving the necessary information required, and the second component is to perform the relationship learning between the features with the reduced dimensionality and the stiffness reduction parameters of the structure. The approach is beneficial as only the EMI spectrum from the healthy structure state is considered for the training of the autoencoders. Second, the superior performance of the proposed framework is demonstrated. The results show that the proposed technique can accurately detect minor damage in its earliest stages for this kind of strengthened structures, while removing the need for manual or signal processing-based damage sensitive feature extraction from EMI signals for damage diagnosis. Finally, research presented in this work can potentially open up new opportunities for successful condition monitoring of this type of strengthened structures, This research was funded by the Spanish Ministry of Science and Innovation (MCIN/AEI), grants number PID2020‐119015GB‐C21 and PID2020‐119015GB‐C22

Although the bond behavior and failure modes of externally bonded reinforcement (EBR) fiber-reinforced polymer (FRP) and hybrid-bonded (HB) systems on concrete have been widely investigated under quasi-static loading, their performance under fatigue loading remains insufficiently understood. Existing research on RC structures strengthened with carbon FRP (CFRP) under cyclic loading has predominantly focused on demonstrating improvements in fatigue life. However, far less attention has been given to examining the bond behavior and the rate of debonding growth, factors that are critical to ensuring the long-term effectiveness and durability of externally bonded CFRP systems. This study experimentally examines the performance of EBR and HB CFRP-to-concrete bonded joints subjected to cyclic fatigue loading. The investigation focuses on the progression of fatigue-induced damage in bonded joints tested under direct pull-out conditions, using CFRP laminates exposed to different maximum cyclic load levels (relative to the static failure load) while keeping a constant load ratio. Under fatigue loading, interfacial debonding between the CFRP laminate and the adhesive was observed, whereas quasi-static tests typically resulted in cohesive failure within the concrete. Results also revealed that increasing the maximum cyclic load markedly accelerated the rate of debonding propagation, The authors acknowledge the support provided by the Spanish Ministry of Science, Innovation and Universities (MICIU/ AEI) through projects PID2020-119015GB-C22/MICIU/AEI/10.13039/501100011033 and TED2021-132198B-I00/ MCIN/AEI/10.13039/501100011033, UE; L.C. acknowledges the grant RYC2021-032171-I funded by MCIN/AEI/ 10.13039/501100011033 and by “European Union NextGenerationEU/PRTR. The authors wish to acknowledge the support of S&P Clever Reinforcement Ibérica Lda for supplying the laminates and the epoxy adhesive used in this study. Open Access funding provided thanks to the CRUE-CSIC agreement with Elsevier

This paper aims to evaluate the influence of relatively high service temperatures (near or beyond the glass transition temperature (Tg) of epoxy adhesive) on the flexural performance and end debonding phenomenon in near-surface mounted (NSM) carbon fiber-reinforced polymer (CFRP)-strengthened, reinforced concrete (RC) beams. To this end, an experimental program consisting of 24 beams (divided into four groups) was performed, where different parameters was combined (i.e., service temperature, steel reinforcement ratio, CFRP ratio, and concrete compressive strength). In addition, the effect of the testing temperature on the end debonding phenomenon was investigated with an analytical procedure according to fib Bulletin 90, and the predictions were compared to experimental results. Taking specimens tested at 20 °C as a reference, no considerable change was observed in the ultimate load of the specimens tested below 60 °C (being in the range of epoxy Tg), and all specimens failed by FRP rupture. On the other hand, the increase in testing temperature up to 70 and 85 °C was followed by a decrease in the capacity of the strengthened beams and a change in failure mode, moving from FRP rupture to end debonding and concrete crushing. The analytical procedure successfully predicted the occurrence of premature end debonding failure and demonstrated that the effect of temperature on the mechanical properties of materials can be a key factor when predicting the premature end debonding in a NSM joint, This research was funded by the Spanish Ministry of Science and Innovation (MCIN/AEI) under projects PID2020-119015GB-C22 and PID2020-119015GB-C21, and by the Generalitat de Catalunya (grant number 2019FI_B 00054)

With the emergence and diversity of various strengthening methods in fibre-reinforced polymer (FRP) strengthened reinforced concrete (RC), understanding and comparing the bond behaviour and active bond mechanisms of these different methods is crucial before their application. In this context, a general method applicable to various strengthening techniques employed to develop accurate bond-slip models and identify the active bond mechanisms is proposed. This approach is based on experimental load-slip behaviour data and does not rely on a predefined model shape. To this end, this paper presents an experimental study on various strengthening techniques, including externally bonded reinforcement (EBR), externally bonded reinforcement on grooves (EBROG), hybrid bonded (HB), and near-surface mounted (NSM), all tested under a single lap-shear test. Here, the results of single-shear bond tests are analysed to examine the manifestation of different activated bond mechanics from various strengthening techniques in the bond-slip law and to compare their bond behaviours, This work was supported by the Spanish Ministry of Science, Innovation and Universities (MICIU/AEI/https://doi.org/10.13039/501100011033) [Project Refs. PID2020-119015 GB-C22 and PID2023-150934NB-C32]; the Generalitat de Catalunya co-funded by Banco Santander [Grant Number IFUdG 2021/01] and the Spanish Ministry of Science and Innovation (MCIN/AEI/https://doi.org/10.13039/501100011033) [Grants Numbers PRE2021-100670 and RYC2021-032171-I

This paper presents a study on the flexural performance of Reinforced Concrete (RC) beams strengthened with Hybrid Bonded (HB) Carbon Fibre Reinforced Polymer (CFRP) laminates. Single-shear tests and flexural tests on RC beams strengthened with CFRP are examined, comparing both Externally Bonded (EB) and HB strengthening techniques with different anchor spacings. Results show that hybrid bonding improved the bond and flexural capacity in single shear and beam tests, respectively. A numerical model is developed to predict Intermediate Crack Debonding (ICD) in RC beams strengthened with HB CFRP laminates. The methodology is based on considering two different bond-slip laws, one for the EB and another for the HB CFRP portions. The proposed model is validated applying the bond-slip laws calibrated from the EB and HB CFRP single-shear tests to the flexural test results, demonstrating accurate prediction of ICD failure for both EB and HB CFRP specimens, This work was supported by the Spanish Ministry of Science and Innovation (MCIN/AEI) under project PID2020-119015GB-C22 (MCIN/AEI/10.13039/5011000011033) and the Generalitat de Catalunya, under the Grant number 2020_FISDU 00476, Open Access funding provided thanks to the CRUE-CSIC agreement with Elsevier

Fiber-reinforced polymer (FRP) strengthening systems have been considered an effective technique to retrofit concrete structures, and their use nowadays is more and more extensive. Externally bonded reinforcement (EBR) and near-surface mounted (NSM) technologies are the two most widely recognized and applied FRP strengthening methods for enhancing structural performance worldwide. However, one of the main disadvantages of both approaches is a possible brittle failure mode provided by a sudden debonding of the FRP. Therefore, methodologies able to monitor the long-term efficiency of this kind of strengthening constitute a challenge to be overcome. In this work, two reinforced concrete (RC) specimens strengthened with FRP and subjected to increasing load tests were monitored. One specimen was strengthened using the EBR method, while for the other, the NSM technique was used. The multiple cracks emanating in both specimens in the static tests, as possible origins of a future debonding failure, were monitored using a piezoelectric (PZT)-transducerbased electromechanical impedance (EMI) technique and a digital image correlation (DIC) system. Clustering approaches based on impedance measurements of the healthy and damaged states of the specimens allowed us to suspect the occurrence of cracks and their growth. The strain profiles captured in the images of the DIC system allowed us to depict surface hair-line cracks and their propagation. The combined implementation of the two techniques to look for correlations during incremental bending tests was addressed in this study as a means of improving the prediction of early cracks and potentially anticipating the complete failure of the strengthened specimens, The writers acknowledge the support for the work reported in this paper from the Spanish Ministry of Science and Innovation (MCIN/AEI) under projects PID2020-119015GB-C21 and PID2020-119015GB-C22

A regulatory framework is required to ensure the correct design of Fibre-Reinforced Polymers (FRPs) increasingly being used as an externally-bonded strengthening system on concrete columns. Several design guidelines on the confinement of FRP concrete have been developed over the past few years worldwide, each proposing a different approach, resulting in different predictions. This study aims to evaluate and compare nine international design guidelines used to predict the compressive strength of confined concrete in FRP-strengthened concrete columns and weigh them against experimental results. The results of this investigation reveal that the predictions from the guidelines on the compressive strengthening of FRP-confined concrete are generally suitable for circular columns, with the ACI-440 and CNR-DT 200 guideline predictions being two of the most accurate. Nevertheless, the guidelines generally tend to overestimate the load-carrying capacity for the compressive strength of FRP-confined concrete in non-circular columns, for which further experimental work using large-scale specimens is required, Confinamiento de columnas de hormigón con FRP: revisión de normativas y sus predicciones. El crecimiento en el uso de polímeros reforzados con fibra (FRP) como sistema de refuerzo externo en columnas de hormigón requiere de un marco regulatorio para su correcto diseño. En los últimos años se han desarrollado diferentes guías y normativas de diseño, teniendo cada una de ellas un planteamiento diferente y, por lo tanto, arrojando resultados dispares. Esta investigación pretende contrastar con resultados experimentales las predicciones que nueve normativas internacionales hacen sobre la resistencia a compresión de una columna de hormigón confinada con FRP. Los resultados de la investigación muestran que las estimaciones de las normativas sobre la resistencia de las columnas de hormigón confinadas con FRP son, en general, adecuadas para columnas circulares; destacan como las más precisas la ACI-440 y la CNR-DT 200. Por contra, en el caso de columnas no circulares los resultados obtenidos tienden a sobreestimar la resistencia a compresión de las columnas confinadas con FRP, en este caso sería necesario continuar investigando en modelos a gran escala, The authors are grateful for the support of the Spanish Government (MCIN), Project Ref. PID2020-119015GB-C22.The authors would also like to thank the Engi-neering School of La Almunia (University of Zara-goza) and the AMADE research group (University of Girona)