Experimental and numerical study of strengthening of heat-damaged RC beams using NSM CFRP strips

Jadooe, Awad; Al-Mahaidi, Riadh; Abdouka, Kamiran

doi:10.1016/j.conbuildmat.2017.07.202

Cited by 41 publications

(7 citation statements)

References 19 publications

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“…Focusing on the existing experimental work, the flexural behavior of NSM strengthened concrete beams under room temperature have been widely studied in the literature [ 14 , 15 , 16 , 17 , 18 , 19 , 20 ], while the structural performance of this technique under elevated temperature and high service temperature is still an open topic that needs detailed research. The fire resistance of FRP-strengthened RC flexural elements has been analyzed in different studies [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. Results from these works showed that the efficiency of the NSM method was better than EBR technique, and the thicker layers of the insulation system helped significantly reduce the temperature in the concrete and the adhesive.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study of the Effect of High Service Temperature on the Flexural Performance of Near-Surface Mounted (NSM) Carbon Fiber-Reinforced Polymer (CFRP)-Strengthened Concrete Beams

et al. 2021

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This paper presents a study of the effect of high service temperature (near or beyond glass transition temperature (Tg) of structural epoxy adhesive) on the behavior of near-surface mounted (NSM) carbon fiber-reinforced polymer (CFRP)-strengthened reinforced concrete (RC) beams. The study includes experimental work as well as analytical and numerical analysis. To this end, fourteen beams have been tested up to failure in two different series. In series 1, specimens with three different CFRP areas have been tested at two different temperatures (i.e., 20 and 40 °C). In series 2, and with the aim of evaluating the effect of higher temperatures, only one CFRP area was tested under four different temperatures (i.e., 20, 60, 70, and 85 °C). Experimental results are evaluated in terms of load–deflections, failure modes, and bond performance. Furthermore, the experimental load–deflection curves are satisfactorily compared to both analytical predictions and finite element (FE) numerical simulations. In both cases, shrinkage and temperature effects on the short-term response of flexural elements have been accounted for. No significant reduction in stiffness and ultimate load was observed for specimens being tested up to 60 °C (in the range of epoxy Tg), showing FRP rupture failure in all of them. For specimens under 70 and 85 °C, the failure mode changed from FRP rupture to FRP end debonding and concrete crushing, respectively.

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Section: Introductionmentioning

confidence: 99%

Experimental Study of the Effect of High Service Temperature on the Flexural Performance of Near-Surface Mounted (NSM) Carbon Fiber-Reinforced Polymer (CFRP)-Strengthened Concrete Beams

et al. 2021

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“…Fire occurrences can also be a source of structural deterioration which could be managed using the NSM FRP strengthening technique. This was shown in research conducted by Jadooe et al [ 64 ], which involved analysis of reinforced concrete beams of similar geometric dimensions, strengthening (using NSM CFRP composites), and loading and support configurations. The study showed that the NSM approach could improve the ultimate load capacity and stiffness of the beams exposed to high temperatures (600–700 °C), though less than the stiffness offered by the original beams not exposed to high-level temperatures.…”

Section: Near-surface Mounted Frp Strengthening Techniques Adopted In...mentioning

confidence: 86%

Experimental Investigation on the Strengthening of Reinforced Concrete Beams Using Externally Bonded and Near-Surface Mounted Natural Fibre Reinforced Polymer Composites—A Review

Effiong

Ede

2022

Materials

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Developing more resilient and sustainable physical infrastructure increases the demand for sustainable materials and strengthening approaches. Many investigations into strengthening RC beam structures have used either externally bonded (EB) or near-surface mounted (NSM) systems with synthetic fibre reinforced polymer composites. These synthetic fibres are unsustainable since they involve the use of nonrenewable resources and a large amount of energy. Research shows that natural fibre reinforced polymer (NFRP) composites may be an alternative to synthetic FRP composites in the strengthening of concrete beams. However, there is limited literature that validates their performance in various structural applications. Hence, the purpose of this paper is to explore the advances, prospects, and gaps of using EB/NSM NFRP techniques in strengthening concrete beams to provide areas for future research directions. The NSM FRP technique provides improved strengthening effects and mitigates the concerns associated with the EB system, based on a wider range of applications using synthetic FRPs. However, the NSM NFRP strengthening technique has been underutilized, though the EB NFRP system has been more commonly explored in reviewed studies. The knowledge gaps and areas for proposed future research directions are essential in developing work in emerging NFRPs and strengthening techniques for sustainable infrastructure.

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“…It pushed back the start of the debonding process and slowed it down in reinforced concrete (RC) beams that had been rebuilt with carbon-fiber-reinforced polymer (CFRP) sheets that were close to the surface. Additionally, the studies [24][25][26][27] mentioned that when compared to beams repaired with cement-based adhesive, beams fixed using epoxy adhesive showed a greater load-bearing capability. These studies found that increasing plate thickness and reducing fastener spacing resulted in improvements in post-fire RC beams repaired using the Bolted Steel Plate (BSP) method.…”

Section: Effectiveness Of the Repair Technique For Fire-damaged Beamsmentioning

confidence: 99%

A Numerical Investigation into the Effectiveness of Composite Jacket Strengthening (CJS) on Fire-Damaged Concrete Beams

Dimia,

Baghdadi,

Belakhdar

et al. 2024

ACSM

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After a fire exposure, reinforced concrete (RC) structures typically retain their integrity, yet they incur significant damage due to material degradation and thermal expansion. The restoration of fire-damaged RC structures is a complex structural engineering challenge. This study presents a numerical investigation on the post-fire behavior of RC beams, subjected to parametric fire for different durations (15, 30, 60, and 90 minutes) and their retrofit method. Initially, the impact of high-temperature conditions on the residual load-bearing capacity is assessed, with a focus on beam length and support conditions as key geometric variables. Repair methods aimed at improving the post-fire performance of damaged beams are then evaluated. These methods include the use of additional reinforcement and the implementation of steel jacketing, complemented by concrete of varying compressive strengths (25,30, 35, and 40 MPa). Eurocode models for both concrete and steel materials are used in the simulations using SAFIR software. Results indicate a decrease in load-carrying capacity with prolonged fire exposure, with capacity reductions reaching 85% for beams subjected to 90-minute fire scenarios. Application of steel jacketing markedly enhances both bending and shear resistance of the compromised beams, with the ability to restore the load-bearing capacity of one-hour fire-exposed beams by up to 112%. The correlation between repair effectiveness and the inherent resistance of the RC beams is also elucidated. Furthermore, an analytical expression is proposed for estimating the post-fire load-bearing capacity of reinforced beams, offering a practical and accurate tool for engineering assessments.

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Experimental and numerical study of strengthening of heat-damaged RC beams using NSM CFRP strips

Cited by 41 publications

References 19 publications

Experimental Study of the Effect of High Service Temperature on the Flexural Performance of Near-Surface Mounted (NSM) Carbon Fiber-Reinforced Polymer (CFRP)-Strengthened Concrete Beams

Experimental Study of the Effect of High Service Temperature on the Flexural Performance of Near-Surface Mounted (NSM) Carbon Fiber-Reinforced Polymer (CFRP)-Strengthened Concrete Beams

Experimental Investigation on the Strengthening of Reinforced Concrete Beams Using Externally Bonded and Near-Surface Mounted Natural Fibre Reinforced Polymer Composites—A Review

A Numerical Investigation into the Effectiveness of Composite Jacket Strengthening (CJS) on Fire-Damaged Concrete Beams

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