Carbon Fiber Reinforced Polymer Rods Research Articles

NSM-CFRP rods with varied embedment depths for strengthening RC T-beams in the negative moment region: Investigation on high cyclic response

Throughout its service life, structural reinforced concrete (RC) encounters cyclic loads and the load amplitude might always vary, leading to a mixed high and low-cycle failure. This research investigates the high cyclic response of RC T-beams strengthened in the negative moment region using near-surface mounted (NSM) Carbon Fiber Reinforced Polymer (CFRP) rods. The distinctive aspect lies in exploring varied embedment depths, including the introduction of half-embedded configurations as an alternative NSM technique. The study comprehensively analyzes load-carrying capacity, failure modes, energy dissipation, ductility, stiffness degradation, and strain behavior, providing insights into the effects of loading rates on structural response. Through an experimental program comparing fully-embedded (BF-D) and half-embedded (BH-D) CFRP rods with a control beam (BN-D) under high-rate cyclic loading, significant increases in ultimate load capacity (21.23% for BH-D and 30.86% for BF-D) are demonstrated despite debonding occurrences. The findings highlight a trade-off between benefits (enhanced ultimate load capacities, improved energy dissipation, and increased stiffness) and drawbacks (reduced ductility and tendencies toward brittle behavior) under high loading rates. Furthermore, a rate-dependent material formula is developed and validated, predicting the flexural strength of the negative moment region in good agreement with experimental results. Finally, this research contributes practical solutions to RC element strengthening challenges and advances understanding of NSM-CFRP-strengthened beam, emphasizing the impact of loading rates on structural response.

Full-Range fatigue behavior of NSM CFRP-to-Concrete bonded joints

The interfacial bond characteristics and failure mechanism of near-surface mounted (NSM) fiber reinforced polymer (FRP) composites in concrete under fatigue loading are less understood compared to their bond behavior under static loading. In this paper, degradation of the local bond strength of FRP-to-concrete bonded joints subjected to direct pull-out fatigue loading is presented for both carbon FRP (CFRP) rods and strips under different fatigue load ranges, i.e., 10–50%, 10–60%, and 10–70%, of the corresponding static load-carrying capacity. The interfacial debonding between FRP and adhesive was observed during fatigue cycles for CFRP rod specimens to different extents. Specimens using CFRP rods with sand-coated and spirally wound surface treatment presented a higher local bond strength and a slower degradation rate, as compared to the ones using CFRP rods with roughened or sand-coated treatment. Using epoxy adhesives with higher strengths benefitted the fatigue bond performance of the tested specimens in terms of local bond strength and stable behavior. Higher fatigue load ranges substantially accelerated the local bond degradation resulting in a much shorter fatigue life of the bonded joints.

Hydrothermal aging of carbon fiber reinforced polymer rods intended for cable applications in civil engineering

Carbon fiber reinforced polymer (CFRP) composites have become increasingly popular due to their high strength-to-weight ratio and excellent mechanical properties. However, CFRP composites are susceptible to hydrothermal aging when used as cable applications in civil engineering, which can cause irreversible damage to their service performance. In this study, the effects of water immersion (water@60 °C), constant temperature and humidity exposure (95%RH@60 °C), and alternating hydrothermal environment (12h_60 °C&12h_25 °C@95%RH) were investigated on the property degradation of the CFRP rods. In addition, the water absorption behavior, and thermal and mechanical properties of the CFRP rods were systematically analyzed and compared. We found that elevated temperature and humidity accelerated the water absorption process, resulting in to the higher equilibrium moisture content and diffusion coefficient. Hydrothermal exposure led to maximum degradation in the tensile strength, three-point bending strength and short-beam shear strength of CFRP rods, with values reaching 4.8%, 17.4% and 24.3% in the water@60 °C, 95%RH@60 °C, and 12h_60 °C&12h_25 °C@95%RH conditions, respectively. Among the three mechanical performance properties analyzed, the tensile strength degradation of the CFRP rods was least affected by the three environmental conditions, primarily due to the tensile direction along the carbon fibers. In addition, the three-point bending and short-beam shear strength values of the CFRP rods showed the greatest degradation in the 12h_60 °C&12h_25 °C@95%RH environment. The long-term effects of the water molecules against the CFRP rods in the hydrothermal environment caused resin hydrolysis and debonding of the fiber-matrix interface, leading to degradation in three-point bending and short-beam shear strength. Additionally, the temperature alternating factor accelerated the degradation of the mechanical properties of the CFRP rods, and the mechanical properties of the CFRP rods declined most noticeably with alternating temperatures under the same moisture content conditions.

The Aging Behavior and Life Prediction of CFRP Rods under a Hygrothermal Environment.

Carbon fiber-reinforced polymer (CFRP) composites have been widely used in civil engineering structures due to their excellent mechanical and durability properties. The harsh service environment of civil engineering leads to significant degradation of the thermal and mechanical performances of CFRP, which then reduces its service reliability, service safety, and life. Research on the durability of CFRP is urgently needed to understand the long-term performance degradation mechanism. In the present study, the hygrothermal aging behavior of CFRP rods was investigated experimentally through immersion in distilled water for 360 days. The water absorption and diffusion behavior, the evolution rules of short beam shear strength (SBSS), and dynamic thermal mechanical properties were obtained to investigate the hygrothermal resistance of CFRP rods. The research results show that the water absorption behavior conforms to Fick's model. The ingression of water molecules leads to a significant decrease in SBSS and glass transition temperature (Tg). This is attributed to the plasticization effect of the resin matrix and interfacial debonding. Furthermore, the Arrhenius equation was used to predict the long-term life of SBSS in the actual service environment based on the time-temperature equivalence theory, obtaining a stable strength retention of SBSS of 72.78%, which was meaningful to provide a design guideline for the long-term durability of CFRP rods.

Experimental Investigation of Fatigue Capacity of Bending-Anchored CFRP Cables.

In this study, the variation of fatigue stiffness, fatigue life, and residual strength, as well as the macroscopic damage initiation, expansion, and fracture of CFRP (carbon fiber reinforced polymer) rods in bending-anchored CFRP cable, were investigated experimentally to verify the anchoring performance of the bending anchoring system and evaluate the additional shear effect caused by bending anchoring. Additionally, the acoustic emission technique was used to monitor the progression of critical microscopic damage to CFRP rods in a bending anchoring system, which is closely related to the compression-shear fracture of CFRP rods within the anchor. The experimental results indicate that after the fatigue cycles of two million, the residual strength retention rate of CFRP rod was as high as 95.1% and 76.7% under the stress amplitudes of 500 MPa and 600 MPa, indicating good fatigue resistance. Moreover, the bending-anchored CFRP cable could withstand 2 million cycles of fatigue loading with a maximum stress of 0.4 σult and an amplitude of 500 MPa without obvious fatigue damage. Moreover, under more severe fatigue-loading conditions, it can be found that fiber splitting in CFRP rods in the free section of cable and compression-shear fracture of CFRP rods are the predominant macroscopic damage modes, and the spatial distribution of macroscopic fatigue damage of CFRP rods reveals that the additional shear effect has become the determining factor in the fatigue resistance of the cable. This study demonstrates the good fatigue-bearing capacity of CFRP cable with a bending anchoring system, and the findings can be used for the optimization of the bending anchoring system to further enhance its fatigue resistance, which further promotes the application and development of CFRP cable and bending anchoring system in bridge structures.

Development and sensing performance study of a smart CFRP cable assembled by multi-group anchorage units

ABSTRACT Carbon fiber reinforced polymer (CFRP) can be applied for bridge cables due to its excellent properties. As the important load-bearing structural component, real-time force monitoring of the CFRP cable is required. This paper presents a new smart CFRP cable that combines the self-sensing rods with embedded sensors and the anchorage system using extrusion technology. By embedding optical fiber (OF) and coaxial cable Fabry-Perot interferometer (CCFPI) into CFRP rods respectively, two types of self-sensing rods (CFRP-OF rod and CFRP-CCFPI rod) were fabricated. A new anchorage unit using an extrusion process was proposed as a basic component of smart CFRP cables. Anchorage units holding a CFRP-OF rod and a CFRP-CCFPI rod were tested to obtain their sensing and mechanical properties. Three anchorage units were assembled to form a smart CFRP cable with self-sensing functionality. A verification test was carried out to confirm the capability of monitoring the cable force. The test results demonstrate that the smart CFRP cable composed of multiple anchorage units has good potential in bridge engineering.

Predicting the behavior of RC T-beams strengthened with NSMCFRP rods in the negative moment region: a finite element approach for low cyclic loading

In this study, a finite element (FE) model for nonlinear FE analysis was developed to evaluate the performance of reinforced concrete (RC) T-beams, which were strengthened in the negative moment region by near-surface mounted (NSM) carbon fiber reinforced polymer (CFRP) rods under low cyclic loading. Furthermore, the rods' depth of embedment was the research variable. Every component of the beam is considered in the model, including the concrete, steel rebars, CFRP rod, CFRP sheet, adhesive, and stirrups. The nonlinear properties of concrete, steel rebars, and adhesive were taken into account, while that of the CFRP was assumed to be linearly elastic till rupture. In addition, the user-programmable capabilities of ABAQUS were used to define the degradation of each material under low cyclic loading. The developed FE model was then compared to some experimental measurements comprising two specimens strengthened with NSM-CFRP rods and one un-strengthened control specimen. Overall, the predicted FE mid-span deflection responses were in line with the corresponding measured experimentally tested data. Finally, the research findings were summarized.

Performance of Compression-free turnbuckle braces using partially fibered CFRP under cyclic load

Turnbuckle braces have been widely used as the seismic-resistant member of steel structures. Being a very slender member, the compressive resistance capacity is not considered in the structural design, but these braces buckle easily due to compressive forces, and the buckling deformation damages the finishing material and causes local plastic strain concentration and plastic fatigue failure. Based on this, the authors of this study developed a compression-free brace that can be easily installed on existing steel turnbuckle braces. We focused on the use of lightweight, high-strength carbon fiber reinforced polymer (CFRP) as a brace material and joined the CFRP rod to the existing steel turnbuckle braces through a pipe style turnbuckle body. The proposed compression-free brace uses partially fibered CFRP (PFCFRP) rods to absorb compressive deformation so that only tensile forces are applied to the brace, and out-of-plane deformation due to buckling is significantly reduced. In addition, the combined use of steel turnbuckle braces can be expected to absorb seismic energy by the plastic deformation of steel. PFCFRP rods are only fiberized in the middle position and the unfiberized position (CFRP rods positions) at both ends are used for the joints. They are molded by pultrusion because of their excellent cost-effectiveness, superior mechanical performance, and stability. The partially fibered sections are created without resin injection. PFCFRP rods are connected to the braces using a pipe-style turnbuckle body. The method used to fix the PFCFRP rod and the pipe-style turnbuckle body involves widening the end of the PFCFRP rod to drive a wedge and insert it into the turnbuckle body. Then, it is filled with steel balls and epoxy resin to prevent it from pulling out. Furthermore, we use the pipe-style turnbuckle body to connect the steel structure like a sleeve joint to provide easy and useful assembly. Two different tests were carried out to confirm the effectiveness of the compression-free braces. Firstly, testing of materials used in compression-free braces was conducted. The results of the tests were used to compare the strength of steel turnbuckle braces to clarify the scope of the application of compression-free braces. Next, cyclic loading tests were carried out on a full-scale steel structural frame to simulate the actual seismic bracing situation. The results show that the proposed compression-free braces have similar historical behavior to existing steel turnbuckle braces. Because the PFCFRP rod absorbs the compressive axial deformation, the out-of-plane deformation can be significantly reduced. These results demonstrate that the proposed compression-free braces using PFCFRP can provide a safe and applicable seismic bracing system.

Charpy impact properties of uni-directional carbon fiber-reinforced polymer tendons with protective layers

The present study explored potential forms of impact protection for carbon fiber-reinforced polymer (CFRP) tendons. Charpy impact tests were performed on CFRP rods and strands under protections of polyvinyl chloride (PVC) and poly-ethylen (PE). In the experimental program, the impact damage pattern and absorbed energy of CFRP tendons with and without external protection were obtained. The results show that the energy absorption capacity of CFRP tendons was improved under the protection of surface layers; and PE layers exhibited the highest protection effectiveness among all protection forms in terms of the increased absorbed energy and caused additional structural weight. Besides, two empirical expressions were established to quantify the relationship between the thickness of PE layers and the energy absorption capacity of the protected CFRP tendons, which may provide a simple tool to estimate the thickness of the layer required for the protection of a specific CFRP tendon in practical applications.

Systematic calibration procedure for CFRP sheets and rods strengthened RC T-beams by using RBSM

In this study, a nonlinear 2D rigid body spring model (RBSM) was developed to verify the experimental works of Carbon Fiber Reinforced Polymer (CFRP) sheets and rods strengthened reinforced concrete (RC) T-shape beam (RC T-beam) section under a combination of bending and shearing loads. Modified Mohr–Coulomb criteria were adopted for modeling the plastic damage of concrete material. The orthotropic smeared layers representing the steel and CFRP materials were laminated on the concrete surface to model the reinforcing steel bars, stirrup steel, and CFRP sheets and rods. A mechanical behavior-based approach to fit the experimental results was discussed using the numerical results at each calibration stage. This study shows how the gradient of compressive and ultimate tensile strength of concrete affects the initial flexure behavior of the load-displacement curve of an RC T-beam. In contrast with finite element modeling, the RBSM can exhibit the crack propagation processes of element separation during the simulation. The calibrations showed the agreement of the models used in predicting the flexural behavior, ultimate load, and strengthening effects of the CFRP sheets and rods to the RC T-beam under bending loads. A systematic calibration procedure combined with the recommended use of energy-based criteria to evaluate the results of calibrated load-displacement curve was proposed.

Cyclic Loading of Glued-In FRP Rods in Timber: Experimental and Analytical Study

The axial load capacity and stiffness of carbon fiber–reinforced polymer (CFRP) and glass fiber–reinforced polymer (GFRP) rods glued in timber is investigated under cyclic loading as the main design consideration for structures that experience load reversal (e.g., due to wind loading). Load cycles at 20%, 40%, 60%, and 80% of the ultimate load and three repetitions per load cycle were considered. The main parameters examined are the effect of FRP rod, anchorage length, and construction scenario. The construction scenarios represent full contact between timber faces, gaps in joints due to long-term effects (e.g., viscoelastic creep) and manufacturing tolerances, and contact with other materials. The GFRP rods exhibit 23% higher axial load capacity and 20% lower axial tensile stiffness than CFRP rods for an embedment length of 5D, where D = diameter of the rod. The axial load capacity of the GFRP rods tends to plateau with increasing bonded length at anchorage lengths greater than 10D. Small gaps significantly decrease the axial compressive stiffness of the glued-in FRP rods at the first load cycles and the axial stiffness varies along the bonded length. An analytical methodology is presented to describe the bond stress transfer mechanism and the progressive bond degradation. The analytical tensile slip values agree fairly well with the experimental results when debonding takes place at 80% of the ultimate load.

Development of a new anchorage system for carbon fiber–reinforced polymer rods using extrusion process

Carbon fiber–reinforced polymer (CFRP) rods have been considered as a candidate material for prestressed concrete applications because of their superior properties. For current applications, successful use of CFRP rods is linked to an efficient anchorage system design. This paper presents a newly developed anchorage system for CFRP rods and the design concept that the extrusion process is used to generate gripping force. The proposed anchorage system consists of a steel barrel and an aluminum sleeve, and an extrusion region is designed on the outside of barrel to generate a suitable contact pressure distribution on the CFRP rod. A mathematical model was proposed to estimate the contact pressure on the CFRP rod and the capacity of anchorage system. The simulation of extrusion and loading process was conducted with a three-dimensional (3D) finite-element (FE) model. The key design parameters of anchorage system were analyzed to obtain an optimized parameter combination. The experimental validation showed that the new anchorage system is capable of allowing the CFRP rod to attain the ultimate tensile strength.

Strengthening of building structures of historical masonry buildings in Syria with carbon fiber reinforced polymer (CFRP) rods and stainless steel helical rods

The article presents the most innovative methods of strengthening and (or) seismic strengthening of masonry for use in historical buildings that are of architectural value, for example, in old mosques in Syria, which are architectural monuments. These methods are designed to protect such buildings, many of which are of architectural and cultural value and are on the UNESCO World Heritage List, from cracks of various sizes and directions and from the negative effects of earthquakes that can occur at any time. Carbon fiber reinforced polymer rods (CFRP) rods and stainless steel helical rods are considered. Two mosques in Syria are briefly described as examples of historical masonry buildings, which are architectural monuments and objects of cultural heritage. In the end conclusions are drawn.

Analysis of Long-Term Prestress Loss in Prestressed Concrete (PC) Structures Using Fiber Bragg Grating (FBG) Sensor-Embedded PC Strands

This study aims to develop a prestressed concrete steel (PC) strand with an embedded optical Fiber Bragg Grating (FBG) sensor, which has been developed by the Korea Institute of Civil Engineering and Building Technology since 2013. This new strand is manufactured by replacing the steel core of the normal PC strand with a carbon-fiber-reinforced polymer (CFRP) rod with excellent tensile strength and durability. Because this new strand is manufactured using the pultrusion method, which is a composite material manufacturing process, with an optical fiber sensor embedded in the inner center of the CFRP Rod, it ensures full composite action as well as proper function of the sensor. In this study, a creep test for maintaining a constant load and a relaxation test for maintaining a constant displacement were performed on the proposed sensor-type PC strand. Each of the two tests was conducted for more than 1000 h, and the long-term performance verification of the sensor-type PC strand was only completed by comparing the performance with that of a normal PC strand. The test specimens were fabricated by applying an optical fiber sensor-embedded PC strand, which had undergone long-term performance verification tests, to a reinforced concrete beam. Depending on whether grout was injected in the duct, the specimens were classified into composite and non-composite specimens. A hydraulic jack was used to prestress the fabricated beam specimens, and the long-term change in the prestress force was observed for more than 1600 days using the embedded optical fiber sensor. The experimental results were compared with the analytical results to determine the long-term prestress loss obtained through finite-element analysis based on various international standards.

CFRP lamella stay-cable and its force measurement based on microwave radar

Carbon Fiber Reinforced Polymer (CFRP) has advantageous characteristics such as lightweight, high strength, high corrosion and fatigue resistance, low creep, and high damping, etc. It is suitable to be used in bridge structures as cables, which can effectively solve the problems of easy rusting, heavyweight, low tensile strength, and low fatigue performance of steel cables. This paper firstly illustrates the advantageous properties of CFRP lamella compared with CFRP rod in terms of cable anchoring and then investigates the performance of wedge-shaped clamp anchorage for CFRP lamella cable by finite element analysis and static tensile test. Finally, the process of measuring the cable force of CFRP lamella stay-cable with non-contact microwave cable force measurement technology is introduced. The finite element analysis and experiment show that the wedge-shaped clamp anchorage can effectively anchor the CFRP lamella stay-cable with a relatively high anchorage efficiency, and the maximum stress of the CFRP lamella stay-cable is at the free section instead of the anchorage section, and the failure pattern is mainly the fiber explosion of the free section. The results of microwave cable force measurement are consistent with those of the traditional pressure sensor and strain gauge methods. The non-contact microwave cable force measurement technology is easy and fast to operate, and it is suitable for measuring the force of CFRP cable.

Influence of high temperatures on the bond between carbon Fibre-Reinforced polymer bars and concrete

The effect of corrosion on reinforced concrete structures can lead to significant economic losses. Therefore, steel bars used in the concrete structures must be replaced with a different material that can withstand water contact without causing corrosion and can ensure the safe operation of the structure during its lifespan, even in adverse weather. Carbon-fibre-reinforced polymer (CFRP) bars are one of the materials that can replace steel bars and they have already been applied as a substitute previously. This study analyses the bonding of these bars with concrete at high temperatures and for longer time periods. It presents an experimental plan that involves a series of pullout trials at different ages, days, and thermal conditions in CFRP rods either treated with ribbed steel bars or that underwent sand-ribbed surface treatment. Some compression tests for each mixture were performed at the same ages and temperatures as the experimental plan in pullout to determine the influence of high temperatures on concrete. The study completed with some complementary tests on the CFRP rods using optical microscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM), from the evaluated pullout samples. The high temperature significantly affected the ribbed CFRP bars by diminishing their bond stress and did not affect the sanded CFRP bars. This uneven behaviour and the influence of high temperature on concrete resistance at the age of 180 d is justified.

Moving-wheel fatigue durability of cantilever bridge deck slab strengthened with high-modulus CFRP rods

Reinforced concrete (RC) slabs of highway bridge decks are gradually deteriorated due to the traffic vehicle wheel-loading. Fatigue is one of a number of possible causes for the deterioration. Cantilever RC slabs of the bridge are also damaged by fatigue loading. To increase the fatigue durability of the bridge deck slab, the near-surface mounted (NSM) technique is used with carbon fiber reinforced polymer (CFRP) rods embedded in the RC slab as an effective strengthening method. This study presents the fatigue characteristics of cantilever RC slabs strengthened with CFRP rods with a high-modulus of elasticity. A cantilever RC slab specimen with embedded CFRP rods with high moduli was constructed on a moving-wheel load testing machine and tested for approximately 11 months. The slab had a minimum thickness of 160 mm (as stipulated by the Japanese design code), and the minimum number of steel reinforcements was embedded to ensure (negative) flexural failure of the RC slab where CFRP rods were not used. During the test, the CFRP strengthened slab specimen was subjected to a negative bending moment from repeated moving-wheel loads. Very limited experimental data are available for the evaluation of the structural behavior of cantilever bridge decks subjected to wheel loads. Therefore, the moving-wheel fatigue experiment of the cantilever RC slab with NSM CFRP rods would be useful information for strengthening. The moving-wheel loading test confirmed the increase in fatigue durability of the CFRP strengthened slab as the slab specimen endured approximately 3.56 million equivalent-cycles at an initial load of 60 kN, which was 32% higher than the designed service load. The experimental investigation revealed that the ultimate failure of the cantilever slab was punching shear failure attributed to the rupture of the CFRP rods.

Efficiency of EB CFRP composites for flexural strengthening of continuous RC beams: A comparative study with NSM CFRP rods

This paper presents an experimental study of the use of carbon fiber-reinforced polymer (CFRP) composites to strengthen two-span reinforced concrete (RC) beams. Six large-scale beams were strengthened in hogging and sagging regions according to the external bonding (EB) technique and then statically tested to investigate the impact of the CFRP position , CFRP form , CFRP layers , and weight of carbon fibers on the flexural performance of continuous beams. The experimental results of the strengthened beams were carefully studied in terms of load-carrying capacity, failure modes, cracking patterns, moment redistribution, and reinforcement strain and compared with the results of an unstrengthened control beam. The efficiency of the EB technique in strengthening continuous RC beams was assessed through a comparative study with the near surface mounted (NSM) technique. For this purpose, another two beam specimens strengthened with NSM-CFRP bars were considered.Based on the experimental results, a general improvement in the flexural performance of strengthened beams was observed. By applying the EB-CFRP composites, the yield and ultimate load capacity could be improved up to 59.1% and 49.8% respectively. . The results also showed that increasing the carbon fiber weight was found to be effective in improving the strength capacity of beams and it may use as an alternative to multiple sheet layers… Comparisons regarding the global flexural performance allow confirming the higher efficiency of the NSM system in comparison to the EB one.

FE analysis and experimental validation of mechanical wedge–barrel anchors for CFRP rods

This paper presents a comparative study of the geometrical optimization of mechanical wedge–barrel anchors for prestressed carbon fiber-reinforced polymer (CFRP) rods. Various anchor configurations were simulated using three-dimensional finite-element (FE) models. The FE models were validated using the draw-ins of the wedges, which were measured in static tensile tests. The configurations consisted of a steel barrel and aluminum wedges, taking advantage of the previous anchors. The conical profile of the wedge and barrel in different configurations had either a curve or a constant differential angle. In addition, a series of geometric modifications were introduced to the wedge at the loading using a fillet or cut. The stress concentration on the CFRP rod was evaluated using failure index Fs in the Tsai–Wu failure criterion for composite materials. The results of the FE simulations showed that a greater differential angle resulted in a smaller stress concentration at the loading end of the anchor and the modifications led to a reduction in the stress concentration. In addition, the anchor with a curved profile was selected as the optimal design because it had the smallest stress concentration owing to the smooth transition of the differential angle distribution along the wedge profile.

Activated Ductile CFRP NSMR Strengthening.

Significant strengthening of concrete structures can be obtained when using adhesively-bonded carbon fiber-reinforced polymer (CFRP) systems. Challenges related to such strengthening methods are; however, the brittle concrete delamination failure, reduced warning, and the consequent inefficient use of the CFRP. A novel ductile near-surface mounted reinforcement (NSMR) CFRP strengthening system with a high CFRP utilization is introduced in this paper. It is hypothesized that the tailored ductile enclosure wedge (EW) end anchors, in combination with low E-modulus and high elongation adhesive, can provide significant strengthening and ductility control. Five concrete T-beams were strengthened using the novel system with a CFRP rod activation stress of approximately 980 MPa. The beam responses were compared to identical epoxy-bonded NSMR strengthened and un-strengthened beams. The linear elastic response was identical to the epoxy-bonded NSMR strengthened beam. In addition, the average deflection and yielding regimes were improved by 220% and 300% (average values), respectively, with an ultimate capacity comparable to the epoxy-bonded NSMR strengthened beam. Reproducible and predictable strengthening effect seems obtainable, where a good correlation between the results and applied theory was reached. The brittle failure modes were prevented, where concrete compression failure and frontal overload anchor failure were experienced when failure was initiated.