Damaged Reinforced Concrete Beams Research Articles

Retrofitting of severely damaged RC beams using novel bio-composite-based mat-matrix system

Due to the rapid urbanization and boom in the infrastructure sector, the frequency of repair and retrofitting in major structures has significantly increased in recent times. Hence, it is essential to adopt a repair/retrofit strategy that not only improves the load-carrying capacity but is also ductile, durable, and cost-effective. In this study, efforts are put forth to develop a novel bio-composite-based mat-matrix strengthening system for restoring the overall performance of severely damaged reinforced concrete (RC) beams. In total, eight full-scale RC beams of span 2.2 m were tested under two different shear span (av) to effective depth (d) ratios of 5.0 and 3.9 to understand the efficiency of proposed strengthening schemes under flexure and shear load combinations. The initial loading of RC beams (i.e. damage phase) showed intense opening of tension cracks in the constant moment zone and crushing at the compression face of the beam. After failure, all the beams were surface prepared and retrofitted with the novel bio-composite mat-matrix system using different combinations of bi-directional flax/hemp fiber mat and discrete flax/hemp fiber based UHTCC matrix. The parameters investigated include (i) type of bio-fiber mat, (ii) type of discrete bio-fiber in UHTCC matrix, and (iii) shear span (av) to effective depth (d) ratio. Results revealed that the proposed composite system was able to completely restore the overall performance of severely damaged RC beams at low av/d ratios. However, in the case of beams with flexure-dominant failure (high av/d), the strengthening system was able to restore about 90% of the ultimate load.

Analytical model for predicting localized damage in RC beams under contact explosion

The determination of damage to reinforced concrete (RC) beams when buildings are exposed to explosives is critical for assessing building destruction and overall stability. However, a well-established theoretical framework for determining the damage of RC beams under contact explosion is currently lacking. In this study, we developed an analytical model to determine the size and shape of the local damage zone in the RC beam subjected to contact explosion. The model analyzes the evolution of damage in the RC beam, considering the function of steel reinforcement and calculating the damage zone. Experimental investigations were conducted using various weights of explosives to study the damage caused by contact explosions on RC beams. By comparing the model with the experimental results, the average error of the analysis model was found to be 9.0 %, providing an accurate calculation of local damage in RC beams and an effective reflection of the dynamic response process. Consequently, these research results can be further used to assess the residual load-bearing capacity of damaged RC beams and predict the extent of damage.

Shear performance evaluation of damaged RC beams strengthened with cast-in-place U-shaped UHPFRC shell

The shear behavior of reinforced concrete (RC) beams may degrade during service, necessitating effective strengthening interventions for these shear-degraded RC members. This study aims to investigate the shear performance of damaged RC beams strengthened by a cast-in-place U-shaped ultra-high performance fiber reinforced concrete (UHPFRC) shell. Four-point flexural tests were performed on one un-strengthened and four UHPFRC shell-strengthened damaged RC beams. In this study, different pre-damage levels for the RC beams (55%, 70%, and 85%) and stirrup ratios within the UHPFRC shell (0.7% and 1.34%) were considered. The failure mode, ultimate capacity, and ductility of these tested RC beams were assessed. The results indicate that the shear capacity of the strengthened beams can be greatly improved by a U-shaped UHPFRC shell, reaching 2.7–3.0 times that of the un-strengthened beams. As the stirrup ratio increased from 0.7% to 1.34%, the failure mode of the strengthened beams changed from shear compression failure to flexure failure, and the ductility increased from 1.56 to 1.96. However, the shear capacity of strengthened beams is slightly influenced by the pre-damage level of the RC beams. Moreover, planting steel rebars at the UHPFRC-RC interfaces effectively improved the interfacial bonding performance. Finally, the shear capacity of the strengthened beams was evaluated by a truss arch model, and the calculated results of the truss arch model are safe as the lower limit of shear capacity.

Deterioration law of flexural performance of RC beams with initial cracks under alternating action of salt freeze-thaw cycles and fatigue

Reinforced concrete (RC) bridges in cold regions are continuously exposed to the combined challenges of traffic loads, freeze–thaw cycles, and salt corrosion. This research delves into the deterioration mechanics and flexural performance of damaged RC beams when subjected to the dual stresses of salt freeze–thaw cycles (SFTCs) and fatigue loading. We conducted performance degradation tests on cracked RC beams subjected to alternating SFTCs and fatigue loading, followed by evaluations of their residual flexural capacities. In-depth analysis considered the impact of the number of alternating cycles and the initial crack width. The results indicate that the combined effects of alternating SFTCs, fatigue loading, and initial cracks significantly diminish the RC beams' flexural strength. As the number of alternating cycles and the initial crack width increased, there was a notable rise in mass loss, rebar corrosion, and a reduction in residual load carrying capacity and stiffness. Particularly, beams without initial cracks saw a 3.61 % reduction in load carrying capacity and a 24.06 % decrease in stiffness after four alternating cycles. In contrast, beams with an initial crack width of 0.10 mm experienced an 11.15 % decline in load carrying capacity and a 38.38 % drop in stiffness. The study concludes that while the combined effects of fatigue loading, SFTCs, and initial cracks are significant, initial cracks exhibit a more pronounced negative influence on load carrying capacity than on stiffness and ductility.

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.

Contribution of steel fibers to the flexural and shear behavior of RC beams damaged by alkali‐silica reaction

AbstractThe study of damage processes in concrete and their effects on the residual properties represents a key point related to the service life of reinforced concrete (RC) structures. The use of steel fibers in RC beams mainly improves the cracking control and the shear bearing capacity. Considering the shear behavior, the presence of fibers not only leads to partial or total substitution of secondary reinforcement, but they can also result in a modification of the failure behavior from a shear failure (brittle) to a bending (ductile) one. The contribution of fibers on flexural and shear behavior of sound and damaged RC beams was investigated using alkali‐silica reaction as a damaging tool. First, the evolution of deformations and cracks were measured on creep tests of RC beams with and without fibers and reactive aggregates. Second, the flexural and shear behavior of damaged and undamaged beams incorporating steel fibers were compared. Results showed that alkali‐silica reaction damage can provoke a reduction of RC beam ductility, while the flexural strength is preserved. Regarding shear, it was observed that even in damaged concrete, fibers were able to control the crack propagation and increase the bearing capacity.

Experimental and numerical study on flexural behaviors of damaged RC beams strengthened with UHPC layer using the bonding technology of post-installed reinforcing bar

Due to the outstanding mechanical and durability properties, Ultra-high performance concrete (UHPC) has been popularly used for strengthening of existing reinforced concrete (RC) beams. To improve the reliability of UHPC strengthening RC beams and enhance the effectiveness of its usage on site applications, bonding technology of post-installed reinforcing bar was proposed to connect the RC beams with UHPC layers. In this paper, a push-out test program was firstly carried out to study the shear properties of interface between UHPC and normal strength concrete (NSC) using the post-installed reinforcing bar connection technology, and to select suitable embedment length of the post-installed reinforcing bar in UHPC layer. Then, a bending test program consisted of three damaged RC beams strengthened with UHPC layers and one control RC beam was conducted to investigate the flexural behaviors of the damaged RC beams strengthened by UHPC layers using the bonding technology of post-installed reinforcing bar. Thereafter, three-dimensional FE models were developed to simulate the flexural performance of the strengthened RC beams, and the crucial parameters were investigated. The results of the present study revealed that the strengthening with reinforced UHPC layers could effectively improve the cracking and flexural performance of damaged RC beams. All the strengthened beams using the bonding technology of post-installed reinforcing bar failed in the typically flexural failure and no obvious interface cracks caused by the interface connection were observed throughout the bending test process.

Detection in RC Beams Damaged and Strengthened with NSM CFRP/GFRP Rods by Free Vibration Monitoring

This paper intends to deepen the topic of damage detection based on non-destructive tests (NDT) for the assessment of the dynamic behavior of RC beams damaged and strengthened both with near-surface mounted (NSM) Carbon and GlassFRP rods. The NSM strengthening with fiber-reinforced polymer (FRP) rods of damaged reinforced concrete (RC) beams is a viable alternative to the traditional strengthening with externally bonded (EB) FRP strips or sheets. In this paper, static tests were foreseen on RC beams to create cracking, and successively, the RC beams strengthened with NSM CFRP and GFRP rods were still investigated using free vibration tests at different loading levels until failure. The purpose of this research is to compare the response of two different types of strengthening of damaged RC beams based on the strength of CFRP and GFRP rods until failure modes. At different steps of loading, the behavior of beams under experimental vibrations has been monitored by frequency response function (FRF) diagrams. Finally, a discussion of the results is presented.

Rehabilitation of Shear damaged Reinforced Concrete Beams with U-Wrapped Carbon Fiber Reinforced Polymer Sheets: Experimental study

This paper presented an experimental study of external rehabilitation of damaged Reinforced Concrete (RC) Beams with Carbon Fibre Reinforced Polymer (CFRP) sheets. The primary objective is to study the shear behavior of four simply supported beam specimens with an total length of 1700mm, a width of 150 mm, and a depth of 250 mm was tested under a monotonic two-point load. The variable used in this study was the specimen damage ratio (50%, 60%, and 70%), while the layout of CFRP sheets and shear-span to effective depth ratio (a/d = 2.5) were kept constant. The design of the examined beams was according to ACI 318M-19 to ensure shear failure. From this study, it was concluded that external rehabilitation with U-shape CFRP sheets offered a very adequate and efficient rehabilitation method for damaged RC beams. Each beam's behavior was examined concerning the crack pattern, first crack load, load-deflection and ultimate load. The CFRP rehabilitation has improved the ultimate load capacity of damaged beams by about 10.91% to 15.96% compared with the expected remaining ultimate load capacity of control specimens without rehabilitation, as well as an increment in the deflection of mid-span from -6.81%, 24.11% at an ultimate load.

Flexural behavior of damaged RC beams strengthened with prestressed UHPC layer

Based on ultra-high-performance concrete (UHPC) and prestressed technique, a new flexural strengthening technology using a prestressed UHPC (PUHPC) layer for the damaged reinforced concrete (RC) structure was proposed in this study. To investigate the flexural strengthening efficiency of PUHPC layer, the bending tests of six beams were carried out in this study, including four PUHPC strengthened RC beams with different pre-damaged degrees (PUB), one reinforced UHPC (RUHPC) strengthened control beam (RUB) and one unstrengthened RC control beam (CB). The experimental results showed that the PUB was typical bending failure. The cracking load and ultimate load of PUB increased by 145% to 190% and 90% to 94% compared with that of CB respectively. Similarly, 98% and 38% of improvement of the characteristic loads comparing with RUB were observed. Moreover, the post cracking stiffness of PUB were significantly improved compared with CB and RUB, while the ductility indexes were decreased. However, with the increase of the pre-damaged degree of RC beam, the cracking resistance, flexural stiffness and ductility of PUB decreased correspondingly. It is worth mentioning that the interface between PUHPC layer and RC beam has a high bond strength, and the slight slip at the interface did not lead to debonding failure during the bending test. Also, the calculation model for predicting the ultimate flexural capacity of PUB was developed, which yielded promising predictions with reasonable accuracy.

Bond of FRP rods in damaged RC beams strengthened with NSM technique

In strengthening reinforced concrete (RC) elements with composite materials, the role of adherence between concrete and FRP assumes great importance as it guarantees the effectiveness of the consolidation method. In this paper the bond mechanisms between FRP rods and concrete second the Near Surface Mounted (NSM) technique have been analyzed by experimental results of investigation and a theoretical linear model. The experimental investigation consists of direct pull-out tests on RC elements with circular GFRP and CFRP rods inserted into a groove. Through pull-out tests main parameters of bond have been presented. The experimental results are compared with those obtained by the theoretical model.

Delamination buckling of GFRP-strips in strengthened RC beams

Fiber Reinforced Polymer (FRP) strips are convenient materials in the strengthening of damaged RC beams of bridges due to corrosion or impact loading and in the rehabilitation of RC beams damaged by seismic actions. The behaviour of Externally Bonded (EB) FRP strips has been extensively studied when the strengthening is subjected to tensile stresses, even if, in many cases, due to cyclic actions, FRP strips glued to the concrete surface may be subjected to compression. Compressive stresses on the FRP strip may cause a buckling mechanism with detachment.In this work, an investigation of reinforced concrete (RC) beam models undamaged and damaged and strengthened with GFRP strips on compressive and tensile sides is shown. Beam models were subjected to four-point bending tests and the delamination buckling mechanism of the GFRP strip has been described. Further, analytical models to study the delamination buckling of strengthening with FRP strips are developed. Finally, experimental and theoretical data are discussed.

IFC‐based semantic modeling of damaged RC beams using 3D point clouds

AbstractIt is important to assess existing reinforced concrete (RC) structures with damages. This task, however, is traditionally empirical and time‐consuming. To improve assessment accuracy and efficiency, this study proposed an approach to semantic model damaged RC beams based on point clouds. A slice‐based method for automatically modeling deformed beams and a color‐based crack detection method were developed for generating building information modeling (BIM) and finite element (FE) models. Furthermore, to enhance structural assessment and decision‐making by providing both damage and loading performance analysis data, a framework to extend the existing IFC standard was proposed for interoperability issues between FE models and BIM, aiming to integrate semantic‐enrichment damages and FE analysis results in the as‐is BIM model. Experiments were carried out on a simply supported RC beam subjected to a concentrated load. As a result, the improvement of the developed as‐is BIM model for damage visualization and structural assessment was confirmed.

Experimental validation of damaged reinforced concrete beam strengthened by pretensioned prestressed ultra-high-performance concrete layer

Strengthening reinforced concrete (RC) beams with ultra-high-performance concrete (UHPC) can improve mechanical properties and durability from previous studies. To further improve UHPC strengthening efficiency, a new technology using a pretensioned prestressed UHPC (P-UHPC) layer for flexural strengthening was proposed in this study. The flexural capacity and crack resistance of the damaged RC beams strengthened by the P-UHPC layer were investigated through a four-point bending test in order for the results to be used in the analysis and design of strengthening damaged structures. The flexural performance of two P-UHPC strengthened beams (PU), one reinforced UHPC (R-UHPC) layer strengthened beam (RU), and one unstrengthened RC control beam (CB) was tested. This study also determined the influence of UHPC shrinkage and prestressing force on the cracking load and ultimate flexural capacity of the P-UHPC strengthened beams by proposing a formal theory. Results showed that the failure modes of the PU beams were typically bending failure. The PU beams showed good composite performance, and there was no debonding failure at the UHPC-RC interface during the test. Moreover, the flexural performance of the damaged RC beams strengthened with the P-UHPC layer was significantly improved, with the average cracking load of the PU beams higher than that of the CB and RU beams by 87.4% and 28.1%, respectively. The average ultimate flexural capacity was 85.2% and 31.7% higher than the CB and RU beams, respectively. In addition, the P-UHPC layer had a more substantial inhibitory effect on the crack development of the damaged RC beams, and the re-expansion load of the cracks in the damaged RC of the PU beams was 111.5 % higher than the RU beam. Finally, the calculation model and theoretical formula for predicting the cracking load and ultimate flexural capacity of the P-UHPC strengthened beams were proposed, and the test results verified the applicability of the proposed calculation methods.

Mathematical statistics algorithm in the bending performance test of corroded reinforced concrete beams under fatigue load

Abstract Harsh environments such as alternating wet and dry conditions and cyclic loading cause erosion in steel bars, leading to severe damage to structures. Steel bars are also prone to bending under long-term fatigue loads. This paper establishes the bending performance test of corroded reinforced concrete (RC) beam under fatigue load based on the mathematical–statistical algorithm. It investigates the influence of heavy load on the fatigue performance of damaged RC beams, the influence of corrosive environment on the fatigue performance of RC beams, the degree of corrosion of steel bars in concrete beams under fatigue loading, and the distribution of chloride ions. The study results found that the stress ratio has a significant effect on the maximum crack width of the specimen beam. The greater is the stress ratio, the longer the fatigue life. This directly affects the performance of the specimen beam under fatigue loading. For this reason, we should pay special attention to the impact of corrosion on the fatigue performance of a structure during the design of steel bars.

Experimental and analytical investigation of using externally bonded, hybrid, fiber-reinforced polymers to repair and strengthen heated, damaged RC beams in flexure

PurposeThis study aims to conduct an experimental study and finite element model (FEM) to investigate the flexural behavior of heat-damaged beams strengthened/repaired by hybrid fiber-reinforced polymers (HFRP).Design/methodology/approachTwo groups of beams of (150 × 250 × 1,200) mm were cast, strengthened and repaired using different configurations of HFRP and tested under four-point loadings. The first group was kept at room temperature, while the second group was exposed to a temperature of 400°C.FindingsIt was found that using multiple layers of carbon fiber-reinforced polymer (CFRP) and glass fiber-reinforced polymer (GFRP) enhanced the strength more than a single layer. Also, the order of two layers of FRP showed no effect on flexural behavior of beams. Using a three-layer scheme (attaching the GFRP first and followed by two layers of CFRP) exhibited increase in ultimate load more than the scheme attached by CFRP first. Furthermore, the scheme HGC (heated beam repaired with glass and carbon, in sequence) allowed to achieve residual flexural capacity of specimen exposed to 400°C. Typical flexural failure was observed in control and heat-damaged beams, whereas the strengthened/repaired beams failed by cover separation and FRP debonding, however, specimen repaired with two layers of GFRP failed by FRP rupture. The FEM results showed good agreement with experimental results.Originality/valueFew researchers have studied the effects of HFRP on strengthening and repair of heated, damaged reinforced concrete (RC) beams. This paper investigates, both experimentally and analytically, the performance of externally strengthened and repaired RC beams, in flexure, with different FRP configurations of CFRP and GFRP.

Novel 3D printed bars for retrofitting heat damaged RC beams

Three-dimensional (3D) printing is a novel technique that has been recently used in producing printed composites for strengthening and rehabilitating complex structures. This research investigates the applicability of printed bars in strengthening and repairing unheated and heat-damaged reinforced concrete (RC) beams. The printed bars were made using Polylactic Acid (PLA) and 20% of carbon fibers. Beams were subjected to a high temperature of 700 °C for 3 h. The Near-surface mounted technique (NSM) was then adopted to strengthen the ordinary RC beams and repair the heat damaged beams using the 3D printed bars. Test results have shown that strengthening and repairing RC beams using the 3D printed bars can increase the load-carrying capacity and the initial stiffness of the beams. The 3D printed bars increased the load-carrying capacity of the heat-damaged beams up to 34%, and hence they restored their load-carrying capacity. The flexural strength was then predicted using the ACI-440 code and compared to the experimental results. The formulations proposed by the ACI-440 for calculating the flexural strength of RC beams strengthened using NSM-FRP bars are applicable but conservative in predicting the flexural strength of the beams strengthened using NSM-3D printed bars.

The behavior of heated damaged shear-deficient RC beams reinforced internally with welded wire mesh

This study implemented an innovative application that integrated WWM as internal shear reinforcement for reinforced concrete (RC) beams. It provides an assessment of this technique's role in enhancing the structural shear capacity before and after being exposed to escalated temperatures. WWM is simple to cut into the desired dimensions and affixed directly to the steel bars without adherent materials. Like the steel shear stirrups, The WWM integrates, totally, with both the RC beam’s concrete and steel bars, where concrete confines them. WWM technique is viable for newly-built RC structural elements and does not apply to retrofit the already-standing elements. For retrofitting purposes, installing an external WWM is a familiar practice. The study parameters were: the WWM layers, the area, and the levels of elevated temperatures. The study monitored structural performance in terms of the ultimate strength, deflection, stiffness, and toughness. The obtained results have shown that the internally installed WWM showed significant effectiveness in enhancing the shear capacity of exposed-to-elevated-temperature RC beams. To predict the severity of damage and the shear capacity of heat-damaged RC beams, a novel guideline is presented, consisting of internally reinforced with WWM; taking into account the effect of the temperature level on the number of WWM's layers. This study's findings have clearly shown that WWM is efficient in enhancing the internal shear reinforcement of exposed-to-escalated-temperature RC beams.

Effects of pre-existing damage and cyclic overloading on the flexural behaviour of RC beams strengthened with prestressed CFRP plates

Using prestressed carbon fibre-reinforced polymer (CFRP) plates to strengthen reinforced concrete (RC) members is of particular interest to maintain the safe operation of existing bridge structures. This work aims to assess the effects of existing damage in RC beams before strengthening and overloading after strengthening on the reliability of this strengthening technique. A series of tests were conducted to simulate load- and corrosion-induced damage in RC beams and to investigate the flexural behaviour and post-fatigue behaviour of damaged RC beams strengthened with prestressed CFRP plates in anchor systems. The experimental results revealed that the coupling action of corrosion- and cyclic overload-induced damage remarkably reduced the flexural stiffness of the strengthened RC beams but did not greatly impact the ultimate load of the strengthened RC beams, indicating the effectiveness of the prestressed strengthening system. After exposure to cyclic overloading, the strengthened RC beams containing load- and steel corrosion-induced damage had an ultimate load retention of more than 80% and had a similar failure mode of concrete crushing. The proposed model agrees well with the experimental results, implying that it could conservatively predict the ultimate load of strengthened RC beams after exposure to a low-cycle overload.

The impact of the welded wire mesh as internal reinforcement on the flexural behavior of RC beams exposed to elevated temperature

This paper investigates the efficiency of using the welded wire mesh (WWM) as internal reinforcement to regain the structural performance of heat-damaged reinforced concrete (RC) beams to achieve a 28-days average compressive cylinder strength of 40 MPa. These (150 × 200 × 1100 mm3) were prepared using ordinary-strength concrete, cured for 28 days in moist burlap, and heat-damaged at temperatures (23–750 Celsius degree (°C)) two hours after internal strengthening. The mechanical response of control and strengthened beams was evaluated under a four-point loading test setup. The reduction percentage is ranged from 7% to 44 %, 2% to 20%,2%–20%, 2 %–31 %, 17 %–65 %, 4 %–36 %, 17 %–40 %, and 17 %–65 % for 250 °C to 750 °C, respectively, in terms of the ultimate load, the ultimate deflection, the elastic stiffness, the energy absorption, the deflection ductility index, the energy ductility index, and the performance factor, respectively. Furthermore, cracking and failure modes were monitored and characterized during the loading process. The results show that exposing reinforced concrete beams (to the above-elevated temperatures) creates intense cracking on their surface and degrades their mechanical performance. The proposed schemes using internal WWM help avert/ reduce the tendency of concrete cover separation. Hence, the overall mechanical performance of heat-damaged beams is noticeably improved. The efficiency of the number of WWM layers is enhanced with further heat damage in which the enhancement percentage is ranged from 15 % to 97 %, 47% to 129%, 12% to 92%, 81 %–415 %, 43 %–123 %, 81 %–415 %, and 69 %–352 % for beams strengthened internally one to five layers of WWM for the ultimate load, the ultimate deflection, the elastic stiffness, the energy absorption, the deflection ductility index, the energy ductility index, and the performance factor, respectively. Finally, this study indicated that using WWM as internal reinforcement represents an acceptable technique for enhancing the loading capacity of flexural-deficient reinforced and thermally damaged RC beams than internal carbon fiber reinforced polymer (CFRP) after considering the profitability index issue. The contribution of one layer of FRP is equivalent to 5.00, 1.31, 1.52, 1.70, 1.10, 1.70, 1.68, and 0.50 times the contribution of one layer of WWM in terms of the ultimate load, the ultimate deflection, the elastic stiffness, the energy absorption, the deflection ductility index, the energy ductility index, the performance factor, and profitability index. Through demonstrating an outstanding structural performance with significant enhancement in the ultimate strength, ultimate deflection, stiffness, and energy absorption, the findings of this paper strongly attest that WWM can be effectively utilized as internal flexural reinforcement in reinforced concrete beams exposed to elevated temperatures. New guidelines are developed for predicting the damage level and flexural strength of heated damaged RC beams internally reinforced with WWM and considering the influence of the number of WWM layers and elevated temperature.