Probabilistic design equations for the shear capacity of RC members with FRP internal shear reinforcement

Lignola, Gian Piero; Jalayer, Fatemeh; Nardone, Fabio; Prota, Andrea; Manfredi, Gaetano

doi:10.1016/j.compositesb.2014.07.007

Cited by 15 publications

(4 citation statements)

References 7 publications

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“…The results of the comparative analyses of procedures included in the design recommendations ACI 440.1R-15 [5], Canadian CSA-S806-12 [8], Japanese JSCE-97 [9] and Italian CNR-DT 203/2006 [10] are presented in Table 3. The results of the comparative analyses of the algorithms proposed by Tottori et al [15], Michaluk et al [16], Deitz et al [17], El-Sayed et al [18], Wegian et al [19], Nehdi et al [20], Hoult et al [21], Razaqpur et al [22], Alam [23], Kara [24], Kurth [25], Jang et al [26], Lignola et al [27], Valivonis et al [28], Thomas et al [29] and Hamid et al [30] are presented in Table 4. 2), ( 7), ( 13) and (17).…”

Section: Verification Of the Available Models And Design Recommendationsmentioning

confidence: 99%

A New Proposal for the Shear Strength Prediction of Beams Longitudinally Reinforced with Fiber-Reinforced Polymer Bars

Bywalski¹,

Drzazga²,

Kamiński³

et al. 2020

Buildings

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This paper investigates composite reinforcement with regard to its use as longitudinal reinforcement. The methods used to calculate the shear strength of concrete members reinforced with fibre-reinforced polymer (FRP) bars are analysed. The main parameters having a bearing on the shear strength of beams reinforced with composite bars are defined. A comparative analysis of the shear strength calculating algorithms provided in the available design recommendations concerning FRP reinforcement and formulas derived by others researchers is carried out. A synthesis of the research to date on sheared concrete members reinforced longitudinally with FRP bars is made. The results of the studies relating to shear strength are compared with the theoretical results yielded by the considered algorithms. A new approach for estimating the shear capacity of support zones reinforced longitudinally with FRP bars without shear reinforcement was proposed and verified. A satisfactory level of model fit was obtained—the best among the available proposals. Taking into account the extended base of destructive testing results, the estimation of the shear strength in accordance with the proposed model can be used as an accompanying (non-destructive) method for the empirical determination of shear resistance of longitudinally reinforced FRP bars.

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Section: Verification Of the Available Models And Design Recommendationsmentioning

confidence: 99%

A New Proposal for the Shear Strength Prediction of Beams Longitudinally Reinforced with Fiber-Reinforced Polymer Bars

Bywalski¹,

Drzazga²,

Kamiński³

et al. 2020

Buildings

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“…It is noted that the model is generally not conservative, however the predictability is quite high (point cloud aligns along 45° line) and the definition of partial safety factors, for design purposes, requires a further step (i.e. a statistical regression based calibration, like as in Lignola et al 2014c, to account for all sources of uncertainties, apart the model equation) out of the scope of present work.…”

Section: Figure 5 Sensitivity Analysis On Parameter Nlmentioning

confidence: 99%

Simplified Modeling of Concrete Confinement

Lignola¹,

Prota²,

Manfredi³

2016

Sustainable Construction Materials and Technologies (SCMT)

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The goal of this research project is to model the effect of confinement on concrete members by means of externally bonded wrapping, hence to provide a simplified closed form solution to determine directly the ultimate confined concrete strength. Common cross-section shapes for reinforced concrete columns are considered herein, namely circular, solid and hollow, square and rectangular. Nowadays innovative materials are developing focusing on the sustainability of the intervention, improving "traditional" FRP materials, where the organic matrix is substituted by an inorganic matrix and fiber fabrics are substituted by biaxial grids, while almost the same fiber materials are adopted. The simplified model is practitioners and code oriented, while it is derived from a more research oriented refined iterative confinement model proposed by the same authors to evaluate the entire stress-strain relationship of confined concrete. Based on a detailed analysis of the stress state, a simplified closed form solution is proposed to account for the non-uniformly confined concrete performance exhibited in non-axisymmetric sections. The non-uniform confining stress field exhibited in such cross-sections is explicitly considered by means of the mean value integral of the pointwise variable stress state over the cross-section. The key aspect of the proposed methodology is the evaluation of the effective equivalent pressure to be inserted in a triaxial confinement model, to account for the peculiarities of square and rectangular cross-sections. Experimental data, available in the literature and representative of a wide stock of applications, were compared to the results of the theoretical simplified model to validate the proposed approach, and satisfactory results were found.

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“…In the case of FRP-RC beams, the deformation and crack width are larger than that of the steel RC beams at the same applying loads. Consequently, the shear resistance provided by both uncracked concrete in the compression zone and aggregated interlock is smaller, which results in a lower shear resistance contribution provided by concrete [10,11]. Additionally, bending FRP rebars to form stirrups significantly reduces the strength at the bend zones due to their anisotropic properties, thus resulting in a lower stirrup shear resistance contribution [12,13].…”

Section: Introductionmentioning

confidence: 99%

Investigation of the Shear Behavior of Concrete Beams Reinforced with FRP Rebars and Stirrups Using ANN Hybridized with Genetic Algorithm

Qin

Zheng

et al. 2023

Polymers

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The shear strength prediction of concrete beams reinforced with FRP rebars and stirrups is one of the most complicated issues in structural engineering applications. Numerous experimental and theoretical studies have been conducted to establish a relationship between the shear capacity and the design variables. However, existing semi-empirical models fail to deliver precise predictions due to the intricate nature of shear mechanisms. To provide a more accurate and reliable model, machine learning (ML) techniques are adopted to study the shear behavior of concrete beams reinforced with FRP rebars and stirrups. A database consisting of 120 tested specimens is compiled from the reported literature. An artificial neural network (ANN) and a combination of ANN with a genetic optimization algorithm (GA-ANN) are implemented for the development of an ML model. Through neural interpretation diagrams (NID), the critical design factors, i.e., beam width and effective depth, shear span-to-depth ratio, compressive strength of concrete, FRP longitudinal reinforcement ratio, FRP shear reinforcement ratio, and elastic modulus of FRP longitudinal reinforcement rebars and FRP stirrups, are identified and determined as input parameters of the models. The accuracy of the proposed models has been verified by comparing the model predictions with the available test results. The application of the GA-ANN model provides better statistical results (mean value Vexp/Vpre equal to 0.99, R2 of 0.91, and RMSE of 22.6 kN) and outperforms CSA S806-12 predictions by improving the R2 value by 18.2% and the RMSE value by 52.5%. Furthermore, special attention is paid to the coupling effects of design parameters on shear capacity, which has not been reasonably considered in the models in the literature and available design guidelines. Finally, an ML-regression equation considering the coupling effects is developed based on the data-driven regression analysis method. The analytical results revealed that the prediction agrees with the test results with reasonable accuracy, and the model can be effectively applied in the prediction of shear capacity of concrete beams reinforced with FRP bars and stirrups.

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Probabilistic design equations for the shear capacity of RC members with FRP internal shear reinforcement

Cited by 15 publications

References 7 publications

A New Proposal for the Shear Strength Prediction of Beams Longitudinally Reinforced with Fiber-Reinforced Polymer Bars

A New Proposal for the Shear Strength Prediction of Beams Longitudinally Reinforced with Fiber-Reinforced Polymer Bars

Simplified Modeling of Concrete Confinement

Investigation of the Shear Behavior of Concrete Beams Reinforced with FRP Rebars and Stirrups Using ANN Hybridized with Genetic Algorithm

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