• Computers and Concrete
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• v.8 no.1
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• pp.59-70
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• 2011

A theoretical model known as the modified rotating-angle softened-truss model (MRA-STM), which is a modification of Rotating-Angle Softened-Truss Model and Modified Compression Field Theory, is presented for the analysis of reinforced concrete membranes in shear. As an application, shear strength and behaviour of reinforced concrete exterior beam-column joints are analysed using the MRA-STM combining with the deep beam analogy. The joints are considered as RC panels and subjected to vertical and horizontal shear stresses from adjacent columns and beams. The strut and truss actions in a beam-column joint are represented by the effective transverse compression stresses and a softened concrete truss in the proposed model. The theoretical predictions of shear strength of reinforced concrete exterior beam-column joints from the proposed model show good agreement with the experimental results.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.181-182
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• 2009

A numerical model is suggested to calculate the long-term resisting capacity of slender Reinforced Concrete(RC) columns subject to axial load with biaxial bending moments. In this model, geometric nonlinearities by the long-term behavior of concrete and P- $\Delta$ effect as well as material nonlinearities by cracking of concrete and yielding of steel are considered. Experimental result from other researchers are compared to verify the proposed model.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.119-120
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• 2010

Recently, for evaluate seismic performance, pseudo-dynamic test and shaking table test are experimented through using small scaled model to relief restriction, though, reserch about similitude law are insufficient. In this study, propose adequate similitude law for improve economical efficiency and reliability.

• Computers and Concrete
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• v.2 no.2
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• pp.147-164
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• 2005

This paper summarizes an experimental study on the seismic behavior of lower stories of a mid-rise reinforced concrete frame building. Two reinforced concrete frames with two stories and one span were tested and each frame represents lower two stories of an 11-story RC frame building. Both frames were designed in accordance with Japanese design guidelines and were identical except in the variation of axial force. The tests demonstrated that the overall load-displacement relations of the two frames were nearly the same and the first-story column shear was closely related to the column axial load. The columns and beams elongated during both of the tests, with the second-floor beam elongation exceeding 1.5% of the beam clear span length. The frame with higher axial loads developed more cracks that the frame under moderate axial load.

• Computers and Concrete
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• v.14 no.3
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• pp.279-297
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• 2014

This paper investigates the effects of confinement reinforcement and concrete strength on nonlinear behaviour of reinforced concrete buildings (RC). For numerical application, an eleven-storey and four bays reinforced concrete frame building is selected. Nonlinear incremental static (pushover) analyses of the building are performed according to various concrete strengths and whether appropriate confinement reinforcement, which defined in Turkish seismic code, exists or not at structural elements. In nonlinear analysis, distributed plastic hinge model is used. As a result of analyses, capacity curves of the frame building and moment-rotation curves at lower end sections of ground floor columns are determined. These results are compared with each other according to concrete strength and whether appropriate confinement reinforcement exists or not, respectively. According to results, it is seen that confinement reinforcement is important factor for increasing of building capacity and decreasing of rotations at structural elements.

• Earthquakes and Structures
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• v.18 no.5
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• pp.599-607
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• 2020

This paper deals with the experimental investigation on the behavior of RCS beam-column exterior joints. Two full-scale specimens of joints between reinforced concrete columns and steel beams are tested under cyclic loading. The objective of the test is to study the effect of steel fiber reinforced concrete (SFRC) on the seismic behavior of RCS joints. The load bearing capacity, story drift capacity, ductility, energy dissipation, and stiffness degradation of specimens are evaluated. The experimental results point out that the FRC joint is increased 20% of load carrying capacity and 30% of energy dissipation capacity in comparison with the RC joint. Besides, the FRC joint shown lower damage and better ductility than RC joint.

• Structural Engineering and Mechanics
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• v.62 no.4
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• pp.391-399
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• 2017

This study investigates the effects of soft story, short columns, heavy overhangs, pounding, and construction and workmanship quality parameters on seismic response of reinforced concrete buildings through nonlinear static and dynamic procedures. The accounted parameters are selected for their common use in rapid screening of RC buildings. The 4- and 7-story buildings designed according to pre-modern codes are used to reflect majority of the existing building stock. The relative penalty scores are employed in this study to evaluate relative importance of certain irregularities in the existing rapid seismic assessment procedures. Comparison of relative scores for the irregularities considered in this study show that the overall trend is similar. The relatively small differences may be accounted for regional construction practices. It is concluded that initial-phase seismic assessment procedures based on architectural features yield in somewhat similar results independent of their bases. However, the differences in the scores emphasize the proper selection of the method based on the regional structure characteristics.

• Structural Engineering and Mechanics
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• v.5 no.6
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• pp.743-754
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• 1997

A three-dimensional constitutive modeling for reinforced concrete is presented for finite element nonlinear analysis of reinforced concrete. The targets of interest to the authors are columns confined by lateral steel hoops, RC thin shells subjected to combined in-plane and out-of-plane actions and massive structures of three-dimensional (3D) extent in shear. The elasto-plastic and continuum fracture law is applied to pre-cracked solid concrete. For post cracking formulation, fixed multi-directional smeared crack model is adopted for RC domains of 3D geometry subjected to monotonic and reversed cyclic actions. The authors propose a new scheme of decomposing stress strain fields into sub-planes on which 2D constitutive laws can be applied. The proposed model for 3D reinforced concrete is experimentally verified in both member and structural levels under cyclic actions.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.03a
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• pp.377-384
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• 2003

Recently, there are much concerns about new and innovative transverse materials which could be used instead of conventional transverse steel in reinforced concrete bridge piers. FRP materials could be substituted for conventional transverse steel because of their sufficient strength, light weight, easy fabrication, and useful applicability to any shapes of pier sections, such as rectangular or circular sections. The objective of this research is to evaluate the seismic performance of reinforced concrete bridge pier specimens with FRP transverse reinforcement by means of the Quasi-Static test. In the first task, test columns were made using FRP rope, but these specimens appeared to fail at low displacement ductility levels due to insufficient confinement of strand extension itself. Therefore, the second task was to evaluate the seismic performance of test specimens transversely confined with FRP band. Although FRP banded specimens showed lower seismic performance than the specimen with spiral reinforcing steel, it satisfied with the response modification factor, 3, required for the single column of Korea bridge roadway design code. It was concluded that FRP band could be efficiently substituted for conventional reinforcing steel.

• Journal of the Korea Institute of Building Construction
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• v.8 no.2
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• pp.113-119
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• 2008

Recently, fiber reinforced polymers(FRP) composite materials are used extensively in the rehabilitation of concrete structural members. A main application is to wrap beams and columns using the continuous fibers sheets to improve their strength and ductility. The corner chamfering affects significantly the performance of the continuous fibers sheets, and could lead to environmental problem with waste and dust. The main purpose of this paper is to verify the effect of corner conditions on the strength of the continuous fiber sheets, and to introduce new attached components which can avoid environmental problem. A total of 15 specimens were tested and carefully checked for three types of continuous fiber sheets(carbon, glass, and aramid) and three types of corner conditions(non-chamfering, chamfering, and device attaching). It is proved that the devices proposed in this research have some capabilities to use for RC member. But additional research will be needed for commercializing.