scholarly journals Evolutionary Modeling to Evaluate the Shear Behavior of Circular Reinforced Concrete Columns

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Alessandra Fiore ◽  
Giuseppe Carlo Marano ◽  
Daniele Laucelli ◽  
Pietro Monaco
Keyword(s):  
Experimental Data ◽  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Columns ◽  
Shear Behavior ◽  
Evolutionary Modeling ◽  
Technical Literature ◽  
Strength Models ◽  
Structured Representation ◽  
Conversion Rules

Despite their frequent occurrence in practice, only limited studies on the shear behavior of reinforced concrete (RC) circular members are available in the literature. Such studies are based on poor assumptions about the physical model, often resulting in being too conservative, as well as technical codes that essentially propose empirical conversion rules. On this topic in this paper, an evolutionary approach named EPR is used to create a structured polynomial model for predicting the shear strength of circular sections. The adopted technique is an evolutionary data mining methodology that generates a transparent and structured representation of the behavior of a system directly from experimental data. In this study experimental data of 61 RC circular columns, as reported in the technical literature, are used to develop the EPR models. As final result, physically consistent shear strength models for circular columns are obtained, to be used in different design situations. The proposed formulations are compared with models available from building codes and literature expressions, showing that EPR technique is capable of capturing and predicting the shear behavior of RC circular elements with very high accuracy. A parametric study is also carried out to evaluate the physical consistency of the proposed models.

Shear strength prediction of short circular reinforced-concrete columns using soft computing methods

2020 ◽  
Vol 23 (14) ◽  
pp. 3048-3061
Author(s):  
Hesam Ketabdari ◽  
Farzad Karimi ◽  
Mahsa Rasouli
Keyword(s):  
Gene Expression ◽  
Experimental Data ◽  
Shear Strength ◽  
Particle Swarm Optimization ◽  
Reinforced Concrete ◽  
Gene Expression Programming ◽  
Particle Swarm ◽  
Concrete Columns ◽  
Swarm Optimization ◽  
Reinforced Concrete Columns

In this article, it has been aimed to predict the shear strength of short circular reinforced-concrete columns using the meta-heuristic algorithms. Based on the studies conducted so far, the parameters dominantly affecting the shear strength include axial force, longitudinal and transverse reinforcement, column dimension ratio, concrete compressive strength and ductility. In this respect, first, 200 numerical models of the short circular reinforced-concrete column incorporating various effective parameters so that a sufficient number of outputs could be provided, are analyzed by ABAQUS software to compute their shear strengths. Then, the gene expression programming and particle swarm optimization algorithms are employed to predict the shear strengths and by means of each algorithm, a relation was proposed accordingly. Then, using the experimental data, these relations are evaluated by comparing with those specified in ACI 318 and ASCE-ACI 426. The results indicate that the percentage of relative error between the experimental data and the values obtained from ACI 318 and ASCE-ACI 426 is respectively equal to 25% and 30%, which have been reduced to 13% and 9% through the gene expression programming and particle swarm optimization algorithms implying the satisfactory performance of these two algorithms. Finally, a comparison of the gene expression programming and particle swarm optimization is investigated in terms of convergence rate, degree of accuracy, and performance mechanism.

Comparison of available shear strength models for non-conforming reinforced concrete columns

2017 ◽  
Vol 148 ◽  
pp. 312-327 ◽  
Author(s):  
Ciro Del Vecchio ◽  
Marta Del Zoppo ◽  
Marco Di Ludovico ◽  
Gerardo Mario Verderame ◽  
Andrea Prota
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Columns ◽  
Reinforced Concrete Columns ◽  
Strength Models

scholarly journals Out-of-Plane Shear Strength of Steel-Plate-Reinforced Concrete Walls Dependent on Bond Behavior

2010 ◽  
Vol 5 (4) ◽  
pp. 385-394 ◽  
Author(s):  
Sung-Gul Hong ◽  
◽  
Wonki Kim ◽  
Kyung-Jin Lee ◽  
Namhee Kim Hong ◽  
...  
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Steel Plate ◽  
Shear Behavior ◽  
Test Results ◽  
Plane Shear ◽  
Concrete Walls ◽  
Reinforced Concrete Walls ◽  
Out Of Plane ◽  
Strength Models

This paper investigates the out-of-plane shear behavior of composite steel-plate-reinforced concrete walls (SC walls) and proposes their shear-strength-models based on plasticity theory limit analysis. For speedy, modular construction, SC walls are fabricated using double-skin steel plates with welded shear studs and sandwiching concrete between them. A review of current design formulas provides better understanding of bond-stress-dependent shear behavior relying on studs of SC walls. We conducted experiments on bondstrength-dependent arch and/or truss action to verify proposed shear-strength models with test results. Test results, including those from literature, agreed well with the strength anticipated by proposed formulas.

scholarly journals Axial Compressive Strength Models of Eccentrically-Loaded Rectangular Reinforced Concrete Columns Confined with FRP

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3498
Author(s):  
Haytham F. Isleem ◽  
Muhammad Abid ◽  
Wesam Salah Alaloul ◽  
Muhammad Kamal Shah ◽  
Shayan Zeb ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Large Scale ◽  
Concrete Strength ◽  
Concrete Columns ◽  
Confined Concrete ◽  
Practice Research ◽  
Small Scale ◽  
Technical Literature ◽  
Rc Columns ◽  
Strength Models

The majority of experimental and analytical studies on fiber-reinforced polymer (FRP) confined concrete has largely concentrated on plain (unreinforced) small-scale concrete columns, on which the efficiency of strengthening is much higher compared with large-scale columns. Although reinforced concrete (RC) columns subjected to combined axial compression and flexural loads (i.e., eccentric compression) are the most common structural elements used in practice, research on eccentrically-loaded FRP-confined rectangular RC columns has been much more limited. More specifically, the limited research has generally been concerned with small-scale RC columns, and hence, the proposed eccentric-loading stress-strain models were mainly based on the existing concentric-loading models of FRP-confined concrete columns of small scale. In the light of such demand to date, this paper is aimed at developing a mathematical model to better predict the strength of FRP-confined rectangular RC columns. The strain distribution of FRP around the circumference of the rectangular sections was investigated to propose equations for the actual rupture strain of FRP wrapped in the horizontal and vertical directions. The model was accomplished using 230 results of 155 tested specimens compiled from 19 studies available in the technical literature. The test database covers an unconfined concrete strength ranging between 9.9 and 73.1 MPa, and section’s dimension ranging from 100–300 mm and 125–435 mm for the short and long sides, respectively. Other test parameters, such as aspect ratio, corner radius, internal hoop steel reinforcement, FRP wrapping layout, and number of FRP wraps were all considered in the model. The performance of the model shows a very good correlation with the test results.

SETTING A DIAGRAM APPROACH TO CALCULATING VIBRATED, CENTRIFUGED AND VIBROCENTRIFUGED REINFORCED CONCRETE COLUMNS WITH A VARIATROPIC STRUCTURE

2020 ◽  
pp. 22-34
Author(s):  
Л. Р. Маилян ◽  
С. А. Стельмах ◽  
Е. М. Щербань ◽  
М. П. Нажуев
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Cross Section ◽  
Concrete Columns ◽  
Reinforced Concrete Columns ◽  
The Cross ◽  
Concrete Elements ◽  
Diagram Approach

Состояние проблемы. Железобетонные элементы изготавливаются, как правило, по трем основным технологиям - вибрированием, центрифугированием и виброцентрифугированием. Однако все основные расчетные зависимости для определения их несущей способности выведены, исходя из основного постулата - постоянства и равенства характеристик бетона по сечению, что реализуется лишь в вибрированных колоннах. Результаты. В рамках диаграммного подхода предложены итерационный, приближенный и упрощенный способы расчета несущей способности железобетонных вибрированных, центрифугированных и виброцентрифугированных колонн. Выводы. Расчет по диаграммному подходу показал существенно более подходящую сходимость с опытными данными, чем расчет по методике норм, а также дал лучшие результаты при использовании дифференциальных характеристик бетона, чем при использовании интегральных и, тем более, нормативных характеристик бетона. Statement of the problem. Reinforced concrete elements are typically manufactured according to three basic technologies - vibration, centrifugation and vibrocentrifugation. However, all the basic calculated dependencies for determining their bearing capacity were derived using the main postulate, i.e., the constancy and equality of the characteristics of concrete over the cross section, which is implemented only in vibrated columns. Results. Within the framework of the diagrammatic approach, iterative, approximate and simplified methods of calculating the bearing capacity of reinforced concrete vibrated, centrifuged and vibrocentrifuged columns are proposed. Conclusions. The calculation according to the diagrammatic approach showed a significantly better convergence with the experimental data than that using the method of norms, and also performs better when using differential characteristics of concrete than when employing integral and particularly standard characteristics of concrete.

scholarly journals Shear Strength of Internal Reinforced Concrete Beam-Column Joints: Intelligent Modeling Approach and Sensitivity Analysis

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
De-Cheng Feng ◽  
Bo Fu
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Influence Factors ◽  
Regression Tree ◽  
Reinforced Concrete Beam ◽  
Gradient Boosting ◽  
Intelligent Modeling ◽  
Modeling Approach ◽  
Ensemble Machine Learning ◽  
Strength Models

In this paper, an intelligent modeling approach is presented to predict the shear strength of the internal reinforced concrete (RC) beam-column joints and used to analyze the sensitivity of the influence factors on the shear strength. The proposed approach is established based on the famous boosting-family ensemble machine learning (ML) algorithms, i.e., gradient boosting regression tree (GBRT), which generates a strong predictive model by integrating several weak predictors, which are obtained by the well-known individual ML algorithms, e.g., DT, ANN, and SVM. The strong model is boosted as each weak predictor has its own weight in the final combination according to the performance. Compared with the conventional mechanical-driven shear strength models, e.g., the well-known modified compression field theory (MCFT), the proposed model can avoid the complicated derivation process of shear mechanism and calibration of the involved empirical parameters; thus, it provides a more convenient, fast, and robust alternative way for predicting the shear strength of the internal RC joints. To train and test the GBRT model, a total of 86 internal RC joint specimens are collected from the literatures, and four traditional ML models and the MCFT model are also employed as comparisons. The results indicate that the GBRT model is superior to both the traditional ML models and MCFT model, as its degree-of-fitting is the highest and the predicting dispersion is the lowest. Finally, the model is used to investigate the influences of different parameters on the shear strength of the internal RC joint, and the sensitivity and importance of the corresponding parameters are obtained.

scholarly journals Cyclic Shear Performance of Reinforced Concrete Columns Strengthened by External Steel Rods

2021 ◽  
Vol 13 (23) ◽  
pp. 13224
Author(s):  
Hyeong-Gook Kim ◽  
Yong-Jun Lee ◽  
Kil-Hee Kim
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Analytical Approach ◽  
Concrete Columns ◽  
Loading Test ◽  
Rc Structures ◽  
Cyclic Shear ◽  
Flexural Failure ◽  
Shear Performance ◽  
Strengthening Method

This study presents a strengthening method for reinforced concrete (RC) columns. The proposed method, which consists of a pair of steel rods, two reverse-threaded couplers, and four corner blocks, is feasible and straightforward. A quasi-static cyclic loading test was performed on the columns externally strengthened by the steel rods. It was found that the corner blocks and the external steel rods with a low prestress level effectively confined the concrete on the compression side of plastic hinges, which eventually induced flexural failure with a ductility higher than three in the strengthened columns. In addition, an analytical approach to predict the shear strength and ultimate flexural strength of the externally strengthened columns was applied. The comparison of analytical and experimental results showed that the analytical approach provided highly accurate predictions on the maximum strength and the failure mode of the externally strengthened columns. It is expected that the application of the proposed method will improve the seismic performance of damaged or deteriorated RC structures, thereby increasing their lifespan expectancy and sustainability.

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