scholarly journals Numerical Analysis of Corrosion Reinforcements in Fibrous Concrete Beams

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Faten Y. Taqi ◽  
Mohammed A. Mashrei ◽  
Hayder M. Oleiwi
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Experimental Results ◽  
Rc Beams ◽  
Steel Fiber Reinforced Concrete ◽  
Steel Bar ◽  
Fibrous Concrete ◽  
Shear Reinforcements

Abstract This paper offers a finite element method (FEM) to simulate the behavior of steel fiber reinforced concrete (SFRC) beams with corrosion of the longitudinal reinforcement using the ABAQUS package. This work was undertaken with the concrete damaged plasticity model (CDP). The expansion of corrosion product was utilized to represent the steel-concrete boundary to study the behavior of SFRC beams. Three beams with three volume fractions of steel fiber (0.8 %, 1.2 %, and 1.8 %) and three reinforced concrete (RC) beams with and without stirrups were created and tested under four-point loading to assess the shear capacity of beams. Corrosion of rebars at one of the RC beams that does not contain shear reinforcements will be studied. The crack patterns and load deflections of these beams were compared with experimental results found by the authors. The conclusions of this analysis will be valuable in considering the structural behavior of SFRC structures with uniform steel bar corrosion using FEM. Analytical results showed that the suggested model is qualified in better simulation and in accuracy of numerical and experimental results. The differences between analytical and experimental results were less than 8 % for load carrying capacity and 14 % for deflection; these differences are also satisfactory within the limits of the engineering conclusion.

scholarly journals Failure Analysis of Steel Fiber-Reinforced Concrete T-Beams without Shear Stirrups

2022 ◽  
Vol 12 (1) ◽  
pp. 411
Author(s):  
Inkyu Rhee
Keyword(s):  
Reinforced Concrete ◽  
Nonlinear Analysis ◽  
Shear Failure ◽  
Steel Fiber ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Reinforced Concrete Member ◽  
Shear Reinforcements

The shear failure of a reinforced concrete member is a sudden diagonal tension failure; flexible failure is gradual, associated with significant cracks, and leads to extensive sagging. Therefore, reinforced shear rebars are commonly used to ensure that flexible failure occurs before shear failure under extreme conditions. Extensive efforts are underway to replace conventional shear reinforcements with steel fibers. Here, a nonlinear analysis of a steel fiber-reinforced concrete T-beam was performed in order to estimate the maximum shear capacity with the aid of experimental test data. A continuum-damaged plasticity model and modified compression field theory were used for nonlinear analysis. Three 360 × 360-mm web elements were selected between the shear span; changes in the principal axis caused by crack development and propagation were traced. Changes in the crack angle according to the average strain of the bottom longitudinal reinforcement and the vertical strain of the web element were also determined. For verification, a strut-tie model was used to predict shear capacity. The experimental results and the finite element analyses were in good agreement.

scholarly journals Using Steel Fiber-Reinforced Concrete Precast Panels for Strengthening in Shear of Beams: An Experimental and Analytical Investigation

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Pitcha Jongvivatsakul ◽  
Linh V. H. Bui ◽  
Theethawachr Koyekaewphring ◽  
Atichon Kunawisarut ◽  
Narawit Hemstapat ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Experimental Program ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Volume ◽  
Simple Formulation

In this paper, the performances of reinforced concrete (RC) beams strengthened in shear with steel fiber-reinforced concrete (SFRC) panels are investigated through experiment, analytical computation, and numerical analysis. An experimental program of RC beams strengthened by using SFRC panels, which were attached to both sides of the beams, is carried out to investigate the effects of fiber volume fraction, connection type, and number and diameter of bolts on the structural responses of the retrofitted beams. The current shear resisting model is also employed to discuss the test data considering shear contribution of SFRC panels. The experimental results indicate that the shear effectiveness of the beams strengthened by using SFRC panels is significantly improved. A three-dimensional (3D) nonlinear finite element (FE) analysis adopting ABAQUS is also conducted to simulate the beams strengthened in shear with SFRC panels. The investigation reveals the good agreement between the experimental and analytical results in terms of the mechanical behaviors. To complement the analytical study, a parametric study is performed to further evaluate the influences of panel thickness, compressive strength of SFRC, and bolt pattern on the performances of the beams. Based on the numerical and experimental analysis, a shear resisting model incorporating the simple formulation of average tensile strength perpendicular to the diagonal crack of the strengthened SFRC panels is proposed with the acceptable accuracy for predicting the shear contribution of the SFRC system under various effects.

scholarly journals A Novel Feature Selection Approach Based on Tree Models for Evaluating the Punching Shear Capacity of Steel Fiber-Reinforced Concrete Flat Slabs

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3902 ◽  
Author(s):  
Shasha Lu ◽  
Mohammadreza Koopialipoor ◽  
Panagiotis G. Asteris ◽  
Maziyar Bahri ◽  
Danial Jahed Armaghani
Keyword(s):  
Feature Selection ◽  
Reinforced Concrete ◽  
Predictive Models ◽  
Steel Fiber ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Punching Shear ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Flat Slabs

When designing flat slabs made of steel fiber-reinforced concrete (SFRC), it is very important to predict their punching shear capacity accurately. The use of machine learning seems to be a great way to improve the accuracy of empirical equations currently used in this field. Accordingly, this study utilized tree predictive models (i.e., random forest (RF), random tree (RT), and classification and regression trees (CART)) as well as a novel feature selection (FS) technique to introduce a new model capable of estimating the punching shear capacity of the SFRC flat slabs. Furthermore, to automatically create the structure of the predictive models, the current study employed a sequential algorithm of the FS model. In order to perform the training stage for the proposed models, a dataset consisting of 140 samples with six influential components (i.e., the depth of the slab, the effective depth of the slab, the length of the column, the compressive strength of the concrete, the reinforcement ratio, and the fiber volume) were collected from the relevant literature. Afterward, the sequential FS models were trained and verified using the above-mentioned database. To evaluate the accuracy of the proposed models for both testing and training datasets, various statistical indices, including the coefficient of determination (R2) and root mean square error (RMSE), were utilized. The results obtained from the experiments indicated that the FS-RT model outperformed FS-RF and FS-CART models in terms of prediction accuracy. The range of R2 and RMSE values were obtained as 0.9476–0.9831 and 14.4965–24.9310, respectively; in this regard, the FS-RT hybrid technique demonstrated the best performance. It was concluded that the three hybrid techniques proposed in this paper, i.e., FS-RT, FS-RF, and FS-CART, could be applied to predicting SFRC flat slabs.

Compressive Properties of High Strength Steel Fiber Reinforced Concrete with Different Fiber Volume Fractions

2013 ◽  
Vol 372 ◽  
pp. 215-218 ◽  
Author(s):  
Hye Ran Kim ◽  
Seung Ju Han ◽  
Hyun Do Yun
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
High Strength Steel ◽  
Steel Fiber ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Experimental Results ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Volume ◽  
Volume Fractions

This paper describes the experimental results of 70 MPa high strength steel fiber reinforced concrete (SFRC) with different steel fiber volume fractions in compression. The effect of steel fiber on fresh properties, compressive strength, toughness index, cracking procedure of high strength steel fiber concrete is also investigated. The steel fibers were added as the volume fractions of 0%, 0.5%, 1.0%, 1.5% and 2.0%. The cylindrical specimens with Φ100 x 200 for compressive tests were manufactured in accordance with ASTM C 39[. The experimental results showed that the slump of fresh SFRC was inversely proportional to the fiber volume fraction added to high strength concrete. As the addition of steel fiber increased, compressive strength of SFRC decreased. Inclusion of steel fiber improves compressive toughness of high strength SFRC.

Shear capacity of cast-in headed anchors in steel fiber-reinforced concrete

2018 ◽  
Vol 171 ◽  
pp. 421-432 ◽  
Author(s):  
Jong-Han Lee ◽  
Baiksoon Cho ◽  
Jae-Bong Kim ◽  
Kun-Joon Lee ◽  
Chi-Young Jung
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete

Experimental Study on Shear Capacity of Prestressed SFRC Beams

2012 ◽  
Vol 256-259 ◽  
pp. 926-929
Author(s):  
Li Bing Jin ◽  
De Cai Chen ◽  
Ji Peng Qi
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Steel Fiber ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Enhancement Effect ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Factors Affecting

In order to study the shear capacity enhancement effect of prestressed technology to steel fiber reinforced concrete, the practical formulas were proposed for evaluating the shear-strength of unbonded prestressed steel-fiber reinforced concrete beams (UPSFRCB) through the test and study of shear capacity of UPSFRCB with simply supported ends. Various factors affecting the shear strength of UPSFRCB, such as steel fiber, prestress and shear-span to depth ratio were analyzed. The result is of importance to the popularization and application of prestressed steel-fiber reinforced concrete.

scholarly journals ANN-based Shear Capacity of Steel Fiber-Reinforced Concrete Beams Without Stirrups

2019 ◽  
Author(s):  
Miguel Abambres ◽  
Eva Olivia Leontien Lantsoght
Keyword(s):  
Reinforced Concrete ◽  
Coefficient Of Variation ◽  
Steel Fiber ◽  
Mean Value ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Current Design

Comparing experimental results on the shear capacity of steel fiber-reinforced concrete (SFRC) beams without mild steel stirrups, to the ones predicted by current design equations and other available formulations, still shows significant differences. In this paper we propose the use of artificial intelligence to estimate the shear capacity of these members. A database of 430 test results reported in the literature is used to develop an artificial neural network-based formula that predicts the shear capacity of SFRC beams without shear reinforcement. The proposed model yields maximum and mean relative errors of 0.0% for the 430 data points, which represents a better prediction (mean Vtest / VANN = 1.00 with a coefficient of variation of 1E-15) than the existing expressions, where the best model yields a mean value of Vtest / Vpred = 1.01 and a coefficient of variation of 27%.

scholarly journals ANN-based Shear Capacity of Steel Fiber-Reinforced Concrete Beams Without Stirrups

2021 ◽  
Author(s):  
Miguel Abambres ◽  
Lantsoght E
Keyword(s):  
Reinforced Concrete ◽  
Coefficient Of Variation ◽  
Steel Fiber ◽  
Mean Value ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Current Design

<p>Comparing experimental results on the shear capacity of steel fiber-reinforced concrete (SFRC) beams without mild steel stirrups, to the ones predicted by current design equations and other available formulations, still shows significant differences. In this paper we propose the use of artificial intelligence to estimate the shear capacity of these members. A database of 430 test results reported in the literature is used to develop an artificial neural network-based formula that predicts the shear capacity of SFRC beams without shear reinforcement. The proposed model yields maximum and mean relative errors of 0.0% for the 430 data points, which represents a better prediction (mean <i>V<sub>test</sub> / V<sub>ANN</sub></i> = 1.00 with a coefficient of variation of 1× 10<sup>-15</sup>) than the existing expressions, where the best model yields a mean value of <i>V<sub>test </sub>/ V<sub>pred</sub></i> = 1.01 and a coefficient of variation of 27%.</p>

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