Strengthened Reinforced Concrete Beams Research Articles

Shear Strengthening of Reinforced Concrete Beams Using Engineered Cementitious Composites and Carbon Fiber-Reinforced Polymer Sheets

This study evaluates the performance of Reinforced Concrete (RC) beams enhanced in shear using Engineered Cementitious Composites (ECCs) and Carbon Fiber-Reinforced Polymers (CFRPs). The experimental study encompasses fifteen RC beams. This set includes one control specimen and fourteen beams fortified in shear with Externally Bonded (EB) composites. Two of these specimens were enhanced with ECC layers, while the remaining were augmented with combined CFRP-ECC layers. Variables in the test included the ECC layer thickness, matrix type, number of CFRP layers, and strengthening configurations such as full wrapping, vertical strips, and inclined strips. The results indicated that the shear capacity of the fortified beams increased by 61.1% to 160.1% compared to the control specimen. The most effective structural performance was observed in the full wrapping method, which utilized a single CFRP layer combined with either 20 mm or 40 mm ECC thickness, outperforming other techniques. However, the inclined strip method demonstrated a notably higher load-bearing capacity than the full wrapping approach for beams with double CFRP layers paired with 20 mm and 40 mm ECC thicknesses. This configuration also exhibited superior ductility compared to the rest. Furthermore, the experimental shear capacities obtained were juxtaposed with theoretical values from prevailing design standards.

Textile Types, Number of Layers and Wrapping Types Effect on Shear Strengthening of Reinforced Concrete Beams with Textile-Reinforced Mortar versus Carbon-Fiber-Reinforced Polymer

In the scope of this study, the strengthening of reinforced concrete beams with different types of composite materials was investigated experimentally and analytically. For the experimental part of the study, a total of seventeen reinforced concrete beams, one with high shear strength and sixteen with low shear strength, were fabricated. The beam with high shear strength and one of the beams with low shear strength were chosen as reference beams. The remaining fifteen beam specimens were strengthened with textile-reinforced mortar (TRM) and carbon-fiber-reinforced polymer (CFRP). While light and heavy carbon mesh were used for strengthening with TRM, unidirectional carbon textile was used for strengthening with CFRP. Other experimental parameters were the spacing of strips, the number of layers (one or two) and the way of wrapping (strip or full). Simply supported beam specimens were tested under three-point loading. Beam specimens were compared in terms of failure mode, ultimate load capacity, ductility index and energy dissipation capacity.

Numerical and analytical modeling of SPH‐ECC strengthened RC beams

AbstractMany studies have suggested that engineered cementitious composite (ECC) could be a highly efficient and cost‐effective material for enhancing the flexural strength of reinforced concrete (RC) beams. Recently two effective retrofitting configurations using steel and polyvinyl‐alcohol hybrid fiber reinforced engineered cementitious composite (SPH‐ECC) were proposed (Qasim et al., Eng Struct, 2023, 284, p. 115992) and their high effectiveness for enhancing the flexural strength of RC beam was verified experimentally. However, to examine the performance of these strengthening configurations thoroughly by conducting experiments to cover practical ranges of design parameters is deemed to be too expensive and time consuming. In this study, a numerical parametric study of SPH‐ECC strengthened RC beams was conducted by employing a validated finite element (FE) modeling procedure developed by the authors. The effects of four key design parameters including the compressive strength of concrete and SPH‐ECC, the thickness of SPH‐ECC strengthening layer and the area of reinforcement bars embedded in SPH‐ECC layers on the flexural performance of the strengthened beams were studied. Parametric study results showed that the area of reinforcement bars in the SPH‐ECC layers could significantly affect the flexural strength of the strengthened beams. Furthermore, in order to allow engineers to predict the flexural strength of the strengthened beams quickly, two simple but accurate analytical models were also developed for the two strengthening configurations considered. Their reliability and accuracy were then verified and confirmed by comparing with the parametric study results.

A review on flexural behavior of reinforced concrete beams strengthened with prestressed carbon fiber reinforced polymer plates

In recent years, with the rapid development of China’s economy, reinforced concrete structure as an economical and good mechanical properties material, is widely used in buildings. In bridge engineering, Carbon Fiber Reinforced Polymer materials is mostly used as externally bonded reinforcement for flexural strengthening of reinforced concrete (RC) beams. However, this method makes the strength of CFRP plates cannot be fully utilized, while the prestressed technology can significantly improve the efficiency of CFRP materials and the flexural strength of the RC beams. This paper compares different methods of prestressed CFRP plates strengthening RC beams and discuss the development of the technology. The results shows that RC beams strengthened with prestressed CFRP plates have better flexural performance. The cracking, yield and ultimate loads increase significantly compared with ordinary beams or non-prestressed strengthened beams. The effectiveness of strengthening process are related to many factors ranging from anchorage methods, prestress levels, ratio of corrosion to bond length. Future research suggestions are also given. At present, most of the experiments are operated in ordinary environment, which is different from the project in real life. More testing environment like chlorine corrosion must be considered. The trials about prestress loss during strengthening process are not enough. There also need more comparative trials in prestressed CFRP plates strengthening concerning prestress loss and non-prestressed CFRP plates.

Study on the effect of pre-stressed level on the force performance of wedge steel plate jacket and steel wire mesh-PCM strengthened RC beams

In this study, the shear behavior of reinforced concrete (RC) beams strengthened with wedge steel plate jacket (WSPJ) and high-strength steel wire mesh-polymer cement mortar (PCM) was investigated. The total contained 6 strengthened beams and 3 control beams, the test variables were the level of prestressing applied to the steel wire and the shear-span ratio of the RC beam. Our findings indicate that shear failure and bending failure were two types of strengthened beams failure, and the WSPJ and steel wire mesh-PCM strengthening technology can effectively improve the shear bearing capacity and ductility of RC beams. Furthermore, it delayed and inhibited the emergence and development of oblique cracks. Under the same shear-to-span ratio, the characteristic load as well as the shear bearing capacity of strengthened RC beams were significantly increased with the increase of prestressing level. The ductility is increased, and the damage mode of strengthened RC beams was changed. Finally, a modified model based on Truss-Arch model was proposed to forecast the shear capacity of strengthened beams. This model considers the impacts of the prestressing level and the shear-to-span ratio and then validated by the experimental data.

Experimental Analysis of an Innovative Double Strap Joint Splicing of GFRP Bars by NSM Methods for Strengthening RC Beams

The double strap joint splicing of glass fiber reinforced polymer (GFRP) bars for reinforced concrete (RC) beams strengthening, applying the near surface mounting (NSM) method, has been proposed in the paper. The proposed method consists of application of the supplementary GFRP bars symmetrically positioned in the cut-off zone of the main GFRP reinforcement. The performances of this splicing method have been experimentally tested for the most unfavorable case of the GFRP reinforcement cut-off in the maximal bending moment zones. During the experiment, the varied parameter has been overlapping length of the bars, taking values of 20∅ and 40∅. Evaluation of the splicing technique is done comparing the experimental results with the results of the behavior of beams strengthened by GFRP bars without cut-off and with cut-off, but without splicing. Experimental research encompassed analysis of strength, stiffness, ductility, crack pattern, strains in the steel, GFRP reinforcement and concrete, and the failure modes of the beams. It has been shown that in case of the cut-off of the GFRP bar, strengthening effectivity decreases for 39%, and that in the case of bypassing the cut-off using double strap 20∅ and 40∅ long, strengthening effectivity decreased 23%, and 14% respectively, compared to the beam without GFRP bar cut-off. Using extrapolation, it has been shown that double strap with length of 60∅ provided strength equivalent to the case without cut-off. The result of application of this splicing method of the additional GFRP bars is significant increase of strength and serviceability of the strengthened RC beams.

Ultimate strength behaviour of reinforced concrete beams strengthened by aluminium-alloy plates

This paper firstly proposed the new strengthening methods on reinforced concrete (RC) structures using the aluminium alloy (AA) plates. Then, the flexural behaviour of RC beams strengthened by externally bonded (EB) and mechanically fastened (MF) AA plates were studied through13 four-point bending tests. Four parameters were studied that included the strengthening method, thickness of AA plate, grade of AAs, and reinforcement ratio. Test results showed that the MF AA beams failed in flexure with concrete crushing, and the EB AA beam exhibited the bonding failure. Compared with EB AA beams, the MF AA beams exhibited larger load carrying capacity and ductility, but lower initial stiffness. Increasing the thickness of AA plate significantly improved the load carrying capacity, but slightly decreased the ductility of MF AA beams. The grade of AA plates exhibited weak influence on MF AA system since the strain of AA plate was significantly limited by the AA plate hole-anchor gap. The strengthening effect was more significant for RC beams with a relatively lower reinforcement ratio. Moreover, theoretical models were proposed to evaluate the ultimate carrying capacity of MF AA beams that considered the strengthening AA plate-concrete slips. Validations of the theoretical predictions against test results showed that they predicted reasonably on the ultimate load carrying capacity of strengthened RC beams by AA plate.

Interfacial stresses of beams hybrid strengthened by steel plate with outside taper and FRP pocket

This study proposes a new hybrid strengthening method, for which the reinforced concrete (RC) beams are strengthened in flexure by externally bonding a steel plate with variable thickness and an FRP pocket with end-anchorage. To investigate the influence of the stress distribution along the bondline on the strengthening effect, this paper develops an interfacial stress analysis model for RC beams strengthened with the proposed method under arbitrary loads. Based on the assumptions of linear elasticity, deformation coordination and static equilibrium conditions, the expressions of normal and shear stresses at the steel-concrete and FRP-steel interfaces of the strengthened RC beams under different loads and boundary conditions are derived. Finally, four-point bending tests on RC beams strengthened in flexure by using the proposed method were carried out. The steel plate with a fillet is beneficial to prevent the end debonding since it can significantly reduce the interfacial stresses at the end of the steel plate. Also, the results show good agreement between the calculated and tested results, which verified the applicability of the proposed model.

Design approach and its optimization for bolted steel plate strengthened RC beams considering the effect of connection bolt slip

The use of bolted steel plates (BSP) has been found to be an effective method for increasing the flexural capacity of reinforced concrete (RC) beams. However, slip in bolt connections is an inevitable occurrence that affects the mechanical behavior of the BSP beam. While prior studies have thoroughly examined the effects of bolt connection slip on the flexural capacity of BSP beams, assuming unlimited slip, experimental results revealed that bolt connection failure takes place when slip surpasses a specific threshold. The current design methodology does not accommodate this finding. To address this issue, a simplified design method for practical applications is proposed. Comprehensive parameter studies were conducted on the enhanced moment capacity ratio and maximum bolt slip, involving a total of 13,824 and 276,480 calculations, respectively. It is found that several parameters (e.g., the aspect ratio of RC beam, the tensile longitudinal reinforcement ratio, the height of steel plate) affect the two above-mentioned indexes. Equations were then developed to determine the enhanced moment capacity ratio and maximum slip. It is noteworthy that the recommended effective yield slip (0.55 mm) is obtained based on adhesive anchor, which should be checked when other types of anchors would be used. Relying on these equations, an optimized design approach for BSP beams is introduced that avoids complex iterative processes. The effectiveness of the optimized design methodology is substantiated through a practical example.

Effect of wetting/drying cycling on flexural behavior of RC beams strengthened by prestressed CFRP plate: Experimental and analytical investigations

Using prestressed carbon fiber reinforced polymers (CFRPs) is a promising technique for strengthening reinforced concrete (RC) structures. This study aimed to investigate the prestress losses and flexural behavior of strengthened RC beams under wetting/drying cycling (WDC) in a chloride-containing environment. Two prestress levels (20% and 40%) and two WDC durations (90 and 180 cycles) were considered. The time-dependent prestress loss under WDC was first monitored by fiber bragg grating (FBG) for 90 days, and the composition of the prestress loss was theoretically analyzed. A four-point bending test was conducted on the strengthened beams after the WDC exposure, and the intermediate crack (IC) debonding strain and the ultimate moment of the strengthened beams were analytically evaluated. The results show that although WDC exposure aggravated the time-dependent prestress losses, the maximum time-dependent prestress losses after 90 WDCs were only 1.75%, indicating the effectiveness of the end anchorage system. After WDC exposure, the failure mode of the strengthened beams shifted from CFRP rupture to IC debonding, accompanied by the reduction of cracking and the ultimate load, CFRP utilization, and the increase of the maximum crack width. Besides, the model of Lu et al. and Said and Wu could be applied to the IC debonding strain prediction after the WDC. When the environmental reduction coefficient was incorporated, ACI 440.2 R and CECS-146 resulted in a precise IC debonding strain. The proposed method could accurately predict the ultimate moment of the prestressed FRP-strengthened RC beams with different failure modes after WDC.

Shear performance of reinforced concrete beams strengthened in shear using NSM bars and reinforced HSC layers

AbstractThe reinforced concrete (RC) beams could be upgraded in shear using steel and fiber‐reinforced polymer (FRP) having several shapes (bars, strips, or sheets). Using near‐surface mounted (NSM) Glass FRP (GFRP) bars is still limited compared to carbon FRP (CFRP) elements as shear reinforcement. Moreover, using reinforced high‐strength concrete layers (HSCL) as NSM shear strengthening for the RC beams is still limited. Herein, three RC beams internally reinforced in shear using different shear areas (without, 100 mm stirrups apart, and 200 mm stirrups apart) were experimentally tested as reference beams (CB). Other eight beams strengthened in shear using NSM HSCL, and bars were experimentally tested. Moreover, an extended finite element (FE) simulation was implemented through a verified FE model to study the effect of other NSM aspects on shear‐strengthened beam response. The results explained that, regardless of the internal stirrups area and external NSM characteristics, the shear‐strengthened beams showed higher load efficiency than the corresponding CB. The NSM upgraded shear beam had slightly higher load efficiency than the un‐strengthened beam having the same steel area as internally shear stirrups. Moreover, increasing the internal shear stirrups decreased the total efficiency of the NSM shear strengthening and the internal stirrups regardless of the NSM characteristics. Furthermore, the NSM HSCL was more efficient than the corresponding NSM bars in increasing the load capacity and stiffness of the shear‐strengthened beams. The reported analytical model predicted well the shear capacity of the tested beams.

STRENGTHENING OF CORROSION-DAMAGED RC BEAMS USING UHPFC LAYERS

In the present work, experimental and numerical investigations were carried out to examine the flexural performance of reinforced concrete (RC) beams after undergoing different degrees of accelerated reinforcement corrosion and strengthened using ultra-high-performance fiber reinforced concrete (UHPFC) layers. The strengthened RC beams were tested under flexure to evaluate the effect of the UHPFC layers (with combinations of three UHPFC layer thicknesses for both options of one-sided and three-sided strengthening) on the failure mode, flexural strength, and stiffness. The flexural strength of the RC beams was significantly enhanced by increasing the thickness of the UHPFC layer. Three-sided strengthening resulted in a higher load-carrying capacity of the RC beams as compared to that of one-sided strengthening. Minimum layer thicknesses required to fully restore the load-carrying capacity of the corroded RC beams were found to be 20 mm and 40 mm for three-sided and one-sided strengthening, respectively. At ultimate load, the mid-span deflections for the strengthened beams were about half of that of the un-strengthened beams due to an increase in the stiffness of the strengthened beams. Finally, the experiment results matched the 3D-FEM predictions, indicating the simulation's accuracy in evaluating corroded-strengthened RC beam flexural performance.

Performance of NSM and EB methods on the flexural capacity of the RC beams strengthened with reinforced HSC layers

The near-surface mounted (NSM), in which strips or rods are fixed by an adhesive in slits formed inside the concrete cover, and the externally bonding (EB), in which the reinforcement is glued to the concrete surface, are well-known strengthening methods. In the present work, an experimental and numerical study was carried out on reinforced concrete (RC) beams strengthened with NSM and EB-reinforced high-strength concrete (RHSC) layers. The RHSC layers were reinforced by steel or glass fiber reinforced polymer (GFRP) rods and bonded to the RC beams without and with a concrete cover. Seven specimens were cast and loaded in flexure up to failure to investigate the effect of RHSC layer position and reinforcement on the RC beams' efficiency. The three-dimensional finite element program (ABAQUS) verified the experimental results numerically. Also, a parametric study was numerically performed to examine the factors affecting the flexural performance of the strengthened RC beams using NSM and EB RHSC layers. The strengthened beams by NSM steel RHSC layers increased the load capacity by 147.9% compared to the control beam (CB). Changing the RHSC layer reinforcement from steel to GFRP bars enhanced the load's efficiencies from 147.9% to 172.0% compared to the CB. Decreasing the width and reinforcing area of the RHSC layer decreased the beam load capacity by about 17.5 %. Due to their longer bending arms, the EB RHSC layers showed lower load capacity than the NSM ones, which accelerated the EB RHSC failure. When the carbon fiber-reinforced polymer bars were utilized to reinforce the HSC layers, the strengthened beams showed higher load efficiency than those strengthened with HSC layers reinforced by GFRP rods.

Flexural strengthening of reinforced concrete beams using textile-reinforced mortar improved with short PVA fibers

Textile-reinforced mortar (TRM) composites were developed to avoid the problems caused by fiber-reinforced polymer (FRP) composites. Furthermore, short and dispersible polyvinyl alcohol (PVA) fibers were applied in TRM matrix to improve the brittle behavior and limit the crack width of TRM composites. In this study, eight reinforced concrete (RC) beams, including two reference beams and six strengthened beams, were designed to investigate the flexural behaviors of RC beams strengthened with PVA fibers-improved TRM composites. The investigation variables were (i) the longitudinal steel bar ratio, (ii) the carbon textile reinforcement ratio, and (iii) the sustaining load level. The test results indicated that (1) TRM composites could effectively limit the crack width of RC beams, and multi-crack behavior was observed in the strengthening overlay. (2) The flexural capacity of strengthened beams was enhanced as the number of textile layers increased. This enhancement came with a decrease in deformation, energy absorption, and ductility to some extent depending on the failure modes. (3) For strengthened RC beams with the sustaining load of 60kN and 96kN, the yield load was decreased by 8% and 16% respectively compared with the strengthened beam without the sustaining load. The enhancement efficiency in yield load was reduced as the sustaining load level increased. However, an acceptable reduction in ductility was obtained. Finally, based on the plane section assumption, an analytical mode was proposed to calculate the flexural capacity and deflection of RC beams strengthened with TRM composites.

Flexural Strength of Damaged RC Beams Repaired with Carbon Fiber-Reinforced Polymer (CFRP) Using Different Techniques

In this study, an experimental program was developed to investigate the flexural behavior of pre-damaged reinforced concrete (RC) beams that had been repaired and strengthened using carbon fiber-reinforced polymer (CFRP) laminates under a monotonic load. Two techniques were used: externally bonded reinforcement (EBR) and near-surface-mounted (NSM) reinforcement, to repair and strengthen the tested beams. The experimental program involved casting and testing nine simply supported RC rectangular beams; one beam was considered as the reference beam and did not undergo additional strengthening, and the remaining beams were strengthened using CFRP laminates. These eight beams were divided into two main groups for the purposes of strengthening: beams for which the EBR technique was used, and beams for which the NSM technique was used. The primary variables observed in the EBR and NSM groups included four damage percentages obtained according to the preload (20, 40, 60, and 80%) from the ultimate load carried by the reference beam. The experimental results show that decreasing the damage percentage leads to an increase in ultimate strength from about 3.6% to 17.2% for the beams repaired using the EBR technique and from 27.6% to 57% for the beams repaired using the NSM technique; additionally, the NSM method was more effective than the EBR method in terms of the flexural strength and mode of failure. However, using CFRP laminates enhances the flexure capacity of strengthened RC beams.

Theoretical and experimental assessment of the effect of adhesive bond thickness on the flexural capacity of CFRP strengthened beams

Carbon Fiber Reinforced Polymer (CFRP) is a material of choice in the structural strengthening of reinforced concrete (RC) elements. In order to strengthen RC elements, CRFP is bonded externally to RC elements using adhesives. This paper investigates the effect of varying adhesive bond thickness on the moment capacity of CFRP strengthened RC beams in flexure. Thirty-eight (38) Reinforced concrete beams (1.2m length) were cast in the laboratory and their failure loads and corresponding moment capacities obtained when the adhesive bond thickness between the CFRP wraps and RC beams were varied. This paper examines the comparison between flexural moment capacities obtained experimentally and the predicted moment capacities using a theoretical procedure set out in AC440-2R-17 after structural strengthening with CFRP. It was observed that the adhesive thickness had a significant effect on the flexural capacity of strengthened beams. As the adhesive thickness increased beyond certain thresholds, the flexural capacity of strengthened beams reduced. At the optimum adhesive thickness threshold, the ACI 440-2r-17 procedures could predict to high accuracy the moment capacities of strengthened beams.

Flexural strengthening of RC beams using GFRP grid bonded with sprayed polyurea

Flexural strengthening of reinforced concrete (RC) beams with fiber reinforced polymer (FRP) was investigated in this research. The bonding agents were an epoxy paste and a sprayed polyurea. Four RC beams were strengthened with FRP composites according to the following techniques: (a) sprayed polyurea with and without glass FRP (GFRP) grid reinforcement; (b) manual layup with one GFRP grid; and (c) manual layup with one GFRP sheet. Experimental results clearly shows that flexural strengthening with polyurea technique is an effective scheme. Other than fast setting, the major advantages of using polyurea over other organic or inorganic matrices are as follows: (a) no slippage of the FRP grid from the polyurea or cracking of the polyurea occurred during the tensile test; (b) no debonding of the polyurea system from strengthened RC beams was observed during the bending test. Application of the polyurea system, key experimental results, and comparison with findings from other research programs reported in literature are presented in this paper.

Load-Displacement and Stiffness Characteristics of Carbon-Fiber Reinforced Polymer (CFRP) Strengthened Reinforced Concrete Beams

In the current study, the efficiency of the carbon-fiber reinforced polymer (CFRP) strengthening technique is experimentally applied to reinforced concrete (RC) beams. In total, four types of test beam specimens are fabricated and tested, labeled as B-1, B-2, B-3, and B-4 for controlled specimens; the beams strengthened at high-level bending-moment regions, beams strengthened at bending-moment regions with enhanced development length, and U-wrapped shear plus flexural strengthened beams, respectively. The control specimens were fabricated under-reinforced in order to exhibit ductile failure according to ACI 318-08. The variation in the CFRP external configuration included a change in the bond length and use of U-shaped strips to limit the CFRP debonding. For strengthening the beams, Sika group CFRP was used in this study. The test specimens were subjected to three-point loading following seven days of strengthening. The test result includes failure modes, load displacement curves, and stiffness degradation. The proposed CFRP strengthening configuration of the RC beams (B-2, B-3, and B-4) demonstrated improved behavior of their load response as compared to that of control beam (B-1). The CFRP configuration used of RC beam B-4 exhibited almost double flexural strength to that of control beam B-1. Moreover, the deformability of the CFRP strengthened RC beams was also increased.

Strengthening of RC beams in shear with novel near-surface mounted (NSM) U-shaped fiber-reinforced polymer (FRP) composites

Over the last three decades, various researchers have proven the high efficiency of the near-surface-mounted (NSM) fiber-reinforced polymer (FRP) method for strengthening reinforced concrete (RC) beams. The shear strengthening of RC beams by embedding FRP bars or strips onto the side concrete cover is a primary application of NSM FRP investigated in numerous studies. These studies revealed that despite the high bond efficiency between the NSM FRP and concrete, NSM FRP shear-strengthened beams frequently failed in debonding modes, such as FRP–concrete interfacial debonding or side concrete cover separation. Such debonding failures limit the strength utilization and strengthening efficiency of the FRP material. Anchoring measures have been proposed for NSM FRPs to mitigate such debonding failures. However, the manufacturing and installation processes of these anchoring devices are complicated. Moreover, interfacial debonding between the NSM FRPs and anchoring devices can still occur. Therefore, this study proposes a novel NSM U-shaped FRP (NUF) device for the shear strengthening of RC beams. The proposed NUF device was fabricated using a fiber sheet through a wet lay-up process. The device can effectively increase the bond efficiency between the FRP and strengthened beam. The concept, manufacturing, and installation processes of this device are discussed. Subsequently, an experiment was performed on seven full-scale RC beams. The test results showed that the proposed NUF device is able to postpone/prevent the debonding failure between NSM FRP and concrete thus largely increase the strengthening efficiency of NSM FRP method.

Performance of corroded RC beams strengthened in flexure using UHPC: Effect of configuration and thickness of the UHPC layers

In the present paper, an experimental investigation was carried out to examine the effect of configurations and thicknesses of ultra high performance fiber reinforced concrete (UHPC) layers on the flexural performance of reinforced concrete (RC) beams strengthened using UHPC layers after undergoing different degrees of accelerated reinforcement corrosion. The beams were tested under flexure to evaluate the effect of UHPC strengthening (with combinations of three UHPC layer thicknesses and two configurations) on failure modes, flexural strengths, and stiffnesses. Statistical analysis of the flexural test results using analysis of variance (ANOVA) showed the significant effects of both configuration and thickness of the UHPC layers on the performance of corrosion-damaged RC beams in flexure, irrespective of the degree of reinforcement corrosion. The RC beams strengthened with UHPC layers applied on three sides exhibited the most significant increase in the ultimate flexural strength in the range of 6 to 63% and an increase in the stiffness in the range of 28 to 112% as compared to that of the uncorroded control beam. Furthermore, analytical models were developed to predict the flexural strength of the corroded beams strengthened using different configurations of UHPC layers. The close agreement of the ultimate flexural strength between the experimentally obtained results and analytically predicted values for the strengthened RC beams indicates the accuracy of the developed analytical models, which can be used to select an optimum strategy for strengthening the corrosion-damaged RC beams.