• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.419-426
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• 2003

Simplified modeling approach for the seismic behavior of a reinforced concrete bridge is investigated in this paper. For this purpose, a hysteretic axial-flexure interaction model was developed and implemented into a nonlinear finite element analysis program. Thus, the seismic response of reinforced concrete bridge piers was evaluated by the simplified point hinge representations. Comparative studies for reinforced concrete bridge piers indicated that the analytical predictions obtained with the new formulations showed a good correlation with experimental results. In addition, seismic response analysis of a reinforced concrete bridge utilizing the simplified point hinge model revealed the adequacy and applicability of the present development.

• Computers and Concrete
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• v.13 no.2
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• pp.235-253
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• 2014

The theoretical basis and the main results of a design procedure, which attempts to provide the optimal layout of ordinary reinforcement in prestressed concrete beams, subjected to bending moment and shear force are presented. The difficulties encountered in simulating the actual behaviour of prestressed concrete beam in presence of coupled forces bending moment - shear force are discussed; particular emphasis is put on plastic models and stress fields approaches. A unified model for reinforced and prestressed concrete beams under axial force - bending moment - shear force interaction is provided. This analytical model is validated against both experimental results collected in literature and nonlinear numerical analyses. Finally, for illustrating the applicability of the proposed procedure, an example of design for a full-scale prestressed concrete beam is shown.

• Computers and Concrete
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• v.23 no.1
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• pp.61-68
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• 2019

This paper presents a computational rational model to predict the ultimate and optimized load capacity of reinforced concrete (RC) beams strengthened by a combination of longitudinal and transverse fiber reinforced polymer (FRP) composite plates/sheets (flexure and shear strengthening system). Several experimental and analytical studies on the confinement effect and failure mechanisms of fiber reinforced polymer (FRP) wrapped columns have been conducted over recent years. Although typical axial members are large-scale square/rectangular reinforced concrete (RC) columns in practice, the majority of such studies have concentrated on the behavior of small-scale circular concrete specimens. A high performance concrete, known as polymer concrete, made up of natural aggregates and an orthophthalic polyester binder, reinforced with non-metallic bars (glass reinforced polymer) has been studied. The material is described at micro and macro level, presenting the key physical and mechanical properties using different experimental techniques. Furthermore, a full description of non-metallic bars is presented to evaluate its structural expectancies, embedded in the polymer concrete matrix. In this paper, the mechanism of mechanical interaction of smooth and lugged FRP rods with concrete is presented. A general modeling and application of various elements are demonstrated. The contact parameters are defined and the procedures of calculation and evaluation of contact parameters are introduced. The method of calibration of the calculated parameters is presented. Finally, the numerical results are obtained for different bond parameters which show a good agreement with experimental results reported in literature.

• Steel and Composite Structures
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• v.29 no.1
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• pp.91-106
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• 2018

This paper investigates the deflection of the steel-concrete composite truss beam (SCCTB) at the serviceability limit state. A precise solution for the distributed uplift force of the SCCTB, considering five different loading types, is first derived based on the differential and equilibrium equations. Furthermore, its approximate solution is proposed for practical applications. Subsequently, the shear slip effect corresponding to the shear stiffness of the stub connectors, uplift effect corresponding to the axial stiffness of the stub connectors and shear effect corresponding to the brace deformation of the steel truss are considered in the derivation of deflection. Formulae for estimating the SCCTB deflection are proposed. Moreover, based on the proposed formulae, a practical design method is developed to provide an effective and convenient tool for designers to estimate the SCCTB deflection. Flexure tests are carried out on three SCCTBs. It is observed that the SCCTB stiffness and ultimate load increase with an increase in the shear interaction factor. Finally, the reliability of the practical design method is accurately verified based on the available experimental results.

• Journal of Korean Society of Steel Construction
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• v.26 no.4
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• pp.289-297
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• 2014

Recently, high performance steels have been utilized to structural materials in buildings and bridges with the demand for high-rise and long-span of main structures. In this paper, flexure-compression members with the high-strength steel were experimentally evaluated to satisfy the design criteria when stub columns fabricated with HSA800 steel were eccentrically loaded. This test was conducted on box-shaped and H-shaped steels stub columns with high-strength steel to verify the P-M interaction of members subjected to combined forces according to axial load ratios. The results showed that all specimens were satisfied the requirements of Korean Building Code(KBC2009) for using of structural members.

• Journal of the Korea Concrete Institute
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• v.25 no.1
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• pp.91-98
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• 2013

The pre-tensioned spun high strength concrete (PHC) pile has poor load carrying capacity in shear and flexure, while showing excellent axial load bearing capacity. The purpose of this study is to evaluate the flexural performance of the concrete-infilled composite PHC (ICP) pile which is the PHC pile reinforced with infilled concrete, transverse and longitudinal reinforcement for the improvement of shear and flexural load carrying capacity. The ICP pile specimen was designed to make allowable axial compression and bending moment higher load bearing capacity than those determined through the investigation of abutment design cases. The allowable axial compression and bending moment of the ICP pile was obtained using the program developed for calculating the axial compression - bending moment interaction. Then, ICP pile specimens were manufactured and flexural tests were performed. From the test results, it was found that the maximum bending moment of the ICP pile was approximately 45% higher than that of the PHC pile and the safety factor of ICP pile design was about 4.5 when the allowable bending moment was determined to be 25% of the flexural strength.