• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.423-428
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• 2000

This Study was conducted to evaluate structural integrity and crack source location of RC structures strengthened with Carbon Fiber Reinforced Plates using acoustic, Four pont bending tests were carried out RC reinforced with C.F.R.P for the several strengthening specimens, the process of fracture was monitored by Acoustic Emission and duration and energy in AE parameters were analyzed. The location and propagation of crack could be easily determined by monitoring AE, which concluded that AE technique could be a very useful tool to evaluate structural integrity of reinforced RC structure.

• Earthquakes and Structures
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• v.1 no.4
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• pp.345-370
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• 2010

The paper presents a study on the numerical simulation of the behaviour of conventional reinforced concrete (RC) beams strengthened by thin fibre-reinforced cementitious matrix (FRCM) jackets. The study covers the cases of retrofitting RC beams with or without stirrups with jackets reinforced with longitudinal and transverse steel reinforcement or with light wire mesh. The strengthened RC beams to be modelled were tested under static monotonic and fully reversing cyclic loading. The numerical results show that the numerical model used predicted quite well the experimental results.

• Steel and Composite Structures
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• v.28 no.4
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• pp.471-482
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• 2018

The composite reinforced concrete and steel (RCS) structural systems have larger structural lateral stiffness, higher inherent structural damping, and faster construction speed than either traditional reinforcement concrete or steel structures. In this paper, four RCS subassemblies with or without the RC slab designed following a strong column-weak beam philosophy were constructed and tested under reversed-cyclic loading. Parameters including the width of slab and composite effect of the RC slab and beam were explored. The test results showed that all specimens performed in a ductile manner with plastic hinges formed in the beam ends near the column faces. The seismic responses of composite connections are influenced significantly by different width of slabs. Compared with that of the steel beam without the RC slab, it was found that the load carrying capacity of composite connections with the RC slab increased by 30% on average, and strength degradation, energy dissipation also had better performance, while the ductility of that were almost the same. Furthermore, the contribution of connection deformation to the overall specimen displacement was analyzed and compared. It decreased approximately 10% due to the coupling effect in the columns and beams with the RC slab. Based on the test result, some suggestions are presented for the design of composite RCS joints.

• Computers and Concrete
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• v.8 no.1
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• pp.71-96
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• 2011

Existing reinforced concrete (RC) beams can be strengthened with externally bolted steel plates to the sides of beams. The effectiveness of this type of bolted side-plate (BSP) beam can however be affected by partial interaction between the steel plates and RC beams due to the mechanical slip of bolts. To avoid over-estimation of the flexural strength and ensure accurate prediction of the load-deformation response of the beams, the effect of partial interaction has to be properly considered. In this paper, a special non-linear macro-finite-element model that takes into account the effects of partial interaction is proposed. The RC beam and the steel plates are modelled as two different elements, interacting through discrete groups of bolts. A layered method is adopted for the formulation of the RC beam and steel plate elements, while a special non-linear model based on a kinematic hardening assumption for the bolts is used to simulate the bolt group effect. The computer program SiBAN was developed based on the proposed approach. Comparison with the available experimental results shows that SiBAN can accurately predict the partial interaction behaviour of the BSP beams. Further numerical simulations show that the interaction between the RC beam and the steel plates is greatly reduced by the formation of plastic hinges and should be considered in analyses of the strengthened beams.

• Computers and Concrete
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• v.19 no.5
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• pp.537-544
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• 2017

The strength and deformational capacity of slender reinforced concrete (RC) columns greatly rely on their slenderness ratios, while an additional secondary moment (i.e., the $P-{\delta}$ effect) can be induced especially when the RC column members are exposed to fire. To evaluate the fire-resisting performances of RC columns, this study proposed an axial force-flexural moment (i.e., P-M) interaction curve model, which can reflect the fire-induced slenderness effects and the nonlinearity of building materials considering the level of stress and the magnitude of temperature. The P-M interaction model proposed in this study was verified in detail by comparing with the fire test results of RC column specimens reported in literature. The verification results showed that the proposed model can properly evaluate the fire-resisting performances of RC column members.

• Multiscale and Multiphysics Mechanics
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• v.1 no.2
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• pp.143-156
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• 2016

Reinforced concrete (RC) structures require advanced analysis techniques for better estimation of their seismic responses, especially in the case of exhibiting complex three-dimensional coupling of torsional and flexural behaviors. This study focuses on validating a numerical approach for evaluating the seismic response of a three-dimensional unsymmetrical RC structure through the participation in the SMART 2013 international benchmark program. The benchmark program provides material properties, detailed drawings of the RC structure, and input ground motions for the seismic response evaluation. In this study, nonlinear constitutive models of concrete and rebar were formed and local tests were conducted to verify the constitutive models in finite element analysis. Elastic calibration of the finite element model of the SMART 2013 RC structure was performed by comparing numerical and experimental results in modal and linear time history analyses. Using the calibrated model, nonlinear earthquake analysis and seismic fragility analysis were performed to estimate the behavior and vulnerability of the RC structure with various ground motions.

• Advances in concrete construction
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• v.8 no.1
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• pp.9-19
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• 2019

This paper describes an experimental investigation on hybrid fiber reinforced concrete (HYFRC) beams. And the main aim of this present paper is to examine the dynamic characteristics and damage evaluation of undamaged and damaged HYFRC beams under free-free constraints. In this experimental work, totally four RC beams were cast and analyzed in order to evaluate the dynamic behavior as well as static load behavior of HYFRCs. Hybrid fiber reinforced concrete beams have been cast by incorporating two different fibers such as steel and polypropylene (PP). Damage of HYFRC beams was obtained by cracking of concrete for one of the beams in each set under four-point bending tests with different percentage variation of damage levels as 50%, 70% and 90% of maximum ultimate load. And the main dynamic characteristics such as damping, fundamental natural frequencies, mode shapes and frequency response function at each and every damage level has been assessed by means of non-destructive technique (NDT) with hammer excitation. The fundamental natural frequency and damping values obtained through dynamic tests for HYFRC beams were compared with control (reference) RC beam at each level of damage which has been acquired through static tests. The static experimental test results emphasize that the HYFRC beam has attained higher ultimate load as compared with control reinforced concrete beam.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.729-732
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• 1999

In this paper, the Mohr-Coulomb criterion was adopted to predict the bonding failure load of the reinforced concrete beams strengthened by the externally bonded steel plates. Based on this criterion, a nonlinear analysis program of APSB(Analysis Program for Strengthened Beams) and nonlinear finite element analysis program of RCSD-SB (Reinforced Concrete Structural Design - Strengthened Beams) were developed. Numerical results were then compared with experimental results and good agreements were obtained.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.577-582
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• 2000

The pseudo-volume control method is developed for the failure analysis of RC slabs, by adding pressure node into layered shell element utilizing in-plane constitutive models of reinforced concrete and layered formulation. For the failure analysis of RC slabs n this paper, geometric nonliearity is also considered in the analysis. The validity of the pseudo-volume control method is verified by comparing analysis results and existing experimental results.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.407-410
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• 2005

This paper describes an evaluation of reinforcement tension in RC beams using the variable truss models. The models were examined with the beam test results by Kim, Kim and White. Consequently, a fixed inclination $\theta$ at the support un-explains global state of internal force flow in cracked reinforced concrete beams subjected to shear and bending. Accordingly, we must introduce the arch factor for development of consistent model in reinforced concrete beams subjected to shear and bending