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1 – 10 of over 2000
Article
Publication date: 1 December 2003

H.Y. Leung

In this study, tests were conducted to investigate the effect of different concretes on the behaviour of reinforced concrete beams with central splices. Five beam

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Abstract

In this study, tests were conducted to investigate the effect of different concretes on the behaviour of reinforced concrete beams with central splices. Five beam specimens were prepared using different concrete mixes in their splice regions. Experimental results indicated that the bond failure of the spliced rebars governed the ultimate flexural behaviour of all specimens, except the one cast with steel fibres. A small increase in flexural strength was found for both the spliced beams cast with high‐strength concrete and steel fibres. Moreover, use of high‐strength concrete and steel fibrous concrete led to a remarkable improvement in the beam's displacement capacity. The effect of pulverised fuel ash on the splice performance was insignificant while the introduction of silica fume caused improvements in loading capacity and ductility.

Details

Structural Survey, vol. 21 no. 5
Type: Research Article
ISSN: 0263-080X

Keywords

Article
Publication date: 9 June 2022

Jinliang Liu and Fangpu Yan

A numerical simulation of the test beam was carried out with Abaqus and compared with test data to ensure that the modeling method is accurate. An analysis of the effects…

Abstract

Purpose

A numerical simulation of the test beam was carried out with Abaqus and compared with test data to ensure that the modeling method is accurate. An analysis of the effects of the angle between the U-hoop and horizontal direction, the pre-crack height, the pre-crack spacing, and the strength of the geopolymer adhesive on the cracking load and ultimate load of the reinforced beam is presented.

Design/methodology/approach

Load tests and finite element simulations were conducted on carbon fiber reinforced polymer-reinforced concrete beams bonded with geopolymer adhesive. The bond-slip effect of geopolymer adhesive was taken into account in the model. The flexural performances, the flexural load capacities, the deformation capacities, and the damage characteristics of the beams were observed, and the numerical simulation results were in good agreement with the experimental results. An analysis of parametric sensitivity was performed using finite element simulation to investigate the effects of different angles between U-hoop and horizontal direction, pre-crack heights, pre-crack spacing, and strength of geopolymer adhesive on cracking load and ultimate load.

Findings

Under the same conditions, the higher the height of the pre-crack, the lower the bearing capacity; increasing the pre-crack spacing can delay cracking, but reduce ultimate load. By increasing the strength of the geopolymer adhesive, the flexural resistance of the beam is improved, and crack development is also delayed; the angle between the u-hoop and horizontal direction does not affect the cracking of reinforced beams; a horizontal u-hoop has a better effect than an oblique u-hoop, and 60° is the ideal angle between the u-hoop and horizontal direction for better reinforcement.

Originality/value

According to the experimental study in this paper, Abaqus was used to simulate the strength of different angles between U-hoop and horizontal direction, pre-crack heights, pre-crack spacings, and geopolymer adhesives, and the angles' effects on the cracking load and load carrying capacity of test beams were discussed. Since no actual tests are required, the method is economical. This paper offers data support for the promotion and application of environmentally friendly reinforcement technology, contributes to environmental protection, and develops a new method for reinforcing reinforced concrete beams and a new concept for finite element simulations.

Details

Multidiscipline Modeling in Materials and Structures, vol. 18 no. 3
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 1 July 1995

Y.N. Ziraba, M.H. Baluch, A.M. Sharif, G.J. Al—Sulaimani, A.K. Azad and I.A. Basunbul

This paper presents a finite element model for analysis of damaged RCbeams strengthened or repaired by externally bonding glass fibre reinforcedplastics (GFRP) on the…

Abstract

This paper presents a finite element model for analysis of damaged RC beams strengthened or repaired by externally bonding glass fibre reinforced plastics (GFRP) on the tension side of the beams. The salient features include: (i) the introduction of a thin, six—noded element to simulate behaviour of the concrete/epoxy glue/GFRP interface and )ii( a scheme of loading a virgin RC beam to a prescribed displacement to simulate damage, unloading and then reloading the damaged RC beam fortified by an externally bonded GFRP plate. Results are presented for RC beams repaired by plates of varying thickness and a transmutation of failure mode is noted from classical flexure for the case of external reinforcement in the form of thin GFRP plates to a unique concrete cover rip off failure for thicker GFRP plates and not predicted by the ACI shear strength formula for diagonal tension failure of unplated RC beams of similar geometry.

Details

Engineering Computations, vol. 12 no. 7
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 4 October 2022

Mojtaba Labibzadeh, Farhad Bostan Shirin and Amin Khajehdezfuly

This study aims to investigate the effects of using circular spirals as the longitudinal reinforcing bars on the performance of the concrete beams subjected to four-point…

Abstract

Purpose

This study aims to investigate the effects of using circular spirals as the longitudinal reinforcing bars on the performance of the concrete beams subjected to four-point bending load.

Design/methodology/approach

The effects of using circular spirals as the longitudinal reinforcing bars on the performance of the concrete beams subjected to four-point bending load are investigated in this study. Employing circular spirals as the main longitudinal reinforcement is a novel idea presented in this paper. In this regard, a finite element model of the beam with spiral longitudinal reinforcement was developed. After model verification, several configurations of concrete beams reinforced by longitudinal spirals were simulated under the four-point loading condition.

Findings

Obtained results showed that using the longitudinal spirals in place of the conventional longitudinal reinforcing bars can improve the bearing capacity of the concrete beam, but at the same time, increases its ductility unacceptably. In other words, the spirals reduce the initial stiffness of the beam significantly. To solve the problem, the authors decided to use the longitudinal spirals as the auxiliary bars added to the main conventional longitudinal bars in the beams. New gained results were satisfactory. By adding the longitudinal spirals to the conventional bars, not only the bearing capacity of the beam increases between 24% and 63%, but also the initial stiffness and ductility of the beam raises between 11%–29% and 3%–57%, respectively, in comparison to the corresponding beam reinforced with conventional longitudinal bars.

Originality/value

Employing circular spirals as the main longitudinal reinforcement is a novel idea presented in this paper.

Details

International Journal of Structural Integrity, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 22 August 2022

Long Liu and Songqiang Wan

To make full use of the tensile strength of near surface mounting (NSM) pasted carbon fiber reinforced plastics (CFRP) strips and further increase the flexural bearing…

11

Abstract

Purpose

To make full use of the tensile strength of near surface mounting (NSM) pasted carbon fiber reinforced plastics (CFRP) strips and further increase the flexural bearing capacity and flexibility of reinforced concrete (RC) beams, a new composite reinforcement method using ultra-high performance concrete (UHPC) layer in the compression zone of RC beams is submitted based on embedding CFRP strips in the tension zone of RC beams. This paper aims to discuss the aforementioned points.

Design/methodology/approach

The experimental beam was simulated by ABAQUS, and compared with the experimental results, the validity of the finite element model was verified. On this basis, the reinforced RC beam is used as the control beam, and parameters such as the CFRP strip number, UHPC layer thickness, steel bar ratio and concrete strength are studied through the verified model. In addition, the numerical calculation results of yield strength, ultimate strength, failure deflection and flexibility are also given.

Findings

The flexural bearing capacity of RC beams supported by the new method is 132.3% higher than that of unreinforced beams, and 7.8% higher than that of RC beams supported only with CFRP strips. The deflection flexibility coefficient of the new reinforced RC beam is 8.06, which is higher than that of the unreinforced beam and the reinforced concrete beam with only CFRP strips embedded in the tension zone.

Originality/value

In this paper, a new reinforcement method is submitted, and the effects of various parameters on the ultimate bearing capacity and flexibility of reinforced RC beams are analyzed by the finite element numerical simulation. Finally, the effectiveness of the new method is verified by the analytical formula.

Details

International Journal of Building Pathology and Adaptation, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2398-4708

Keywords

Article
Publication date: 30 March 2022

Jinliang Liu and Fangpu Yan

In this paper, the effects of geopolymer adhesive, the number of CFRP layers and the width of pre-crack on the flexural performance of reinforced concrete beams

Abstract

Purpose

In this paper, the effects of geopolymer adhesive, the number of CFRP layers and the width of pre-crack on the flexural performance of reinforced concrete beams strengthened with CFRP were studied, and the flexural capacity of strengthened beams was calculated theoretically.

Design/methodology/approach

Reinforced concrete beams were strengthened with CFRP by geopolymer adhesive, and flexural load tests were conducted to observe the reinforcement effect. Based on the method of calculating the flexural capacity of reinforced concrete beams, a theoretical calculation model on the flexural capacity of reinforced concrete beams strengthened with geopolymer adhesive bonded CFRP was established.

Findings

The test data shown the flexural capacity of epoxy resin adhesive CFRP strengthened reinforced concrete beams is 7.76% higher than that geopolymer adhesive is used. The flexural capacity of reinforced concrete beams strengthened with three layers of CFRP is 1.86% higher than that two layers are adopted. The mean ratio of the test data and the calculation results of the flexural capacity is 0.973, and the mean square error is 0.008. It can be seen that the test data are in good agreement with the theoretical value.

Originality/value

This paper provides data support for the popularization and application of the new environment-friendly reinforcement technology, contributes to the cause of environmental protection, and provides a new method for strengthening reinforced concrete beams.

Details

International Journal of Structural Integrity, vol. 13 no. 3
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 1 October 2018

Jiawei Wang, Jinliang Liu, Guanhua Zhang and Yanmin Jia

The calculation of the shear capacity of inclined section for prestressed reinforced concrete beams is an important topic in the design of concrete members. The purpose of…

Abstract

Purpose

The calculation of the shear capacity of inclined section for prestressed reinforced concrete beams is an important topic in the design of concrete members. The purpose of this paper, based on the truss-arch model, is to analyze the shear mechanism in prestressed reinforced concrete beams and establish the calculation formula for shear capacity.

Design/methodology/approach

Considering the effect of the prestressed reinforcement axial force on the angle of the diagonal struts and regression coefficient of softening cocalculation of shear capacity is established. According to the shape of the cracks of prestressed reinforced concrete beams under shear compression failure, the tie-arch model for the calculation of shear capacity is established. Shear-failure-test beam results are collected to verify the established formula for shear bearing capacity.

Findings

Through theoretical analysis and experimental beam verification, it is confirmed in this study that the truss-arch model can be used to analyze the shear mechanism of prestressed reinforced concrete members accurately. The calculation formula for the angle of the diagonal struts chosen by considering the effect of prestress is accurate. The relationship between the softening coefficient of concrete and strength of concrete that is established is correct. Considering the effect of the destruction of beam shear plasticity of the concrete on the surface crack shape, the tie-arch model, which is established where the arch axis is parabolic, is applicable.

Originality/value

The formula for shear capacity of prestressed reinforced concrete beams based on this theoretical model can guarantee the effectiveness of the calculation results when the structural properties vary significantly. Engineers can calculate the parameters of prestressed reinforced concrete beams by using the shear capacity calculation formula proposed in this paper.

Details

International Journal of Structural Integrity, vol. 9 no. 5
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 3 January 2017

Shamsad Ahmad

This study aims to make an effort to develop a model to predict the residual flexural strength of reinforced concrete beams subjected to reinforcement corrosion.

Abstract

Purpose

This study aims to make an effort to develop a model to predict the residual flexural strength of reinforced concrete beams subjected to reinforcement corrosion.

Design/methodology/approach

For generating the required data to develop the model, a set of experimental variables was considered that included corrosion current density, corrosion duration, rebar diameter and thickness of concrete cover. A total of 28 sets of reinforced concrete beams of size 150 × 150 × 1,100 mm were cast, of which 4 sets of un-corroded beams were tested in four-point bend test as control beams and the remaining 24 sets of beams were subjected to accelerated rebar corrosion inducing different levels of corrosion current densities for different durations. Corroded beams were also tested in flexure, and test results of un-corroded and corroded beams were utilized to obtain an empirical model for estimating the residual flexural strength of beams for given corrosion current density, corrosion duration and diameter of the rebars.

Findings

Comparison of the residual flexural strengths measured experimentally for a set of corroded beams, reported in literature, with that predicted using the model proposed in this study indicates that the proposed model has a reasonably good accuracy.

Originality/value

The empirical model obtained under this work can be used as a simple tool to predict residual flexural strength of corroded beams using the input data that include rebar corrosion rate, corrosion duration after initiation and diameter of rebars.

Details

Anti-Corrosion Methods and Materials, vol. 64 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 4 January 2022

Pandimani, Markandeya Raju Ponnada and Yesuratnam Geddada

The partially prestressed concrete beam with unbonded tendon is still an active field of research because of the difficulty in analyzing and understanding its behavior…

Abstract

Purpose

The partially prestressed concrete beam with unbonded tendon is still an active field of research because of the difficulty in analyzing and understanding its behavior. The finite-element (FE) simulation of such beams using numerical software is very scarce in the literature and therefore this study is taken to demonstrate the modeling aspects of unbonded partially prestressed concrete (UPPSC) beams. This study aims to present the three-dimensional (3-D) nonlinear FE simulations of UPPSC beams subjected to monotonic static loadings using the numerical analysis package ANSYS.

Design/methodology/approach

The sensitivity study is carried out with three different mesh densities to obtain the optimum elements that reflect on the load–deflection behavior of numerical models, and the model with optimum element density is used further to model all the UPPSC beams in this study. Three half-symmetry FE model is constructed in ANSYS parametric design language domain with proper boundary conditions at the symmetry plane and support to achieve the same response as that of the full-scale experimental beam available in the literature. The linear and nonlinear material behavior of prestressing tendon and conventional steel reinforcements, concrete and anchorage and loading plates are modeled using link180, solid65 and solid185 elements, respectively. The Newton–Raphson iteration method is used to solve the nonlinear solution of the FE models.

Findings

The evolution of concrete cracking at critical loadings, yielding of nonprestressed steel reinforcements, stress increment in the prestressing tendon, stresses in concrete elements and the complete load–deflection behavior of the UPPSC beams are well predicted by the proposed FE model. The maximum discrepancy of ultimate moments and deflections of the validated FE models exhibit 13% and −5%, respectively, in comparison with the experimental results.

Practical implications

The FE analysis of UPPSC beams is done using ANSYS software, which is a versatile tool in contrast to the experimental testing to study the stress increments in the unbonded tendons and assess the complete nonlinear response of partially prestressed concrete beams. The validated numerical model and the techniques presented in this study can be readily used to explore the parametric analysis of UPPSC beams.

Originality/value

The developed model is capable of predicting the strength and nonlinear behavior of UPPSC beams with reasonable accuracy. The load–deflection plot captured by the FE model is corroborated with the experimental data existing in the literature and the FE results exhibit good agreement against the experimentally tested beams, which expresses the practicability of using FE analysis for the nonlinear response of UPPSC beams using ANSYS software.

Details

Journal of Engineering, Design and Technology , vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 4 August 2021

Pandimani, Markandeya Raju Ponnada and Yesuratnam Geddada

This study aims to present comprehensive nonlinear material modelling techniques and simulations of reinforced concrete (RC) beams subjected to short-term monotonic static…

Abstract

Purpose

This study aims to present comprehensive nonlinear material modelling techniques and simulations of reinforced concrete (RC) beams subjected to short-term monotonic static load using the robust and reliable general-purpose finite element (FE) software ANSYS. A parametric study is carried out to analyse the flexural and ductility behaviour of RC beams under various influencing parameters.

Design/methodology/approach

To develop and validate the numerical FE models, a total of four experimentally tested simply supported RC beams are taken from the available literature and two beams are selected from each author. The concrete, steel reinforcements, bond-slip mechanism, loading and supporting plates are modelled using SOLID65, LINK180, COMBIN39 and SOLID185 elements, respectively. The validated models are then used to conduct parametric FE analysis to investigate the effect of concrete compressive strength, percentage of tensile reinforcement, compression reinforcement ratio, transverse shear reinforcement, bond-slip mechanism, concrete compressive stress-strain constitutive models, beam symmetry and varying overall depth of beam on the ultimate load-carrying capacity and ductility behaviour of RC beams.

Findings

The developed three-dimensional FE models can able to capture the load and midspan deflections at critical points, the accurate yield point of steel reinforcements, the formation of initial and progressive concrete crack patterns and the complete load-deflection curves of RC beams up to ultimate failure. From the numerical results, it can be concluded that the FE model considering the bond-slip effect with Thorenfeldt’s concrete compressive stress-strain model exhibits a better correlation with the experimental data.

Originality/value

The ultimate load and deflection results of validated FE models show a maximum deviation of less than 10% and 15%, respectively, as compared to the experimental results. The developed model is also capable of capturing concrete failure modes accurately. Overall, the FE analysis results were found quite acceptable and compared well with the experimental data at all loading stages. It is suggested that the proposed FE model is a practical and reliable tool for analyzing the flexural behaviour of RC members and can be used for performing parametric studies.

Details

World Journal of Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1708-5284

Keywords

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