• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.373-376
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• 2004

The designer has difficulty due to inadequacy of provisions in the domestic design code and lack of understanding for behavior of D-region. The rectangular shaped corbel consist of various failure mechanisms as the crushing or splitting from compression concrete, and shearing failure under the loading plate. However, predicting those failure mechanisms is very difficult. In this study, rectangular shaped corbel is analyzed and designed by using strut-tie model. Adequacy for the application of strut-tie model is verified by comparison with the way used in current design practice. The results show that strut-tie model can be a rational and an economical design than current conventional design methods.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.619-622
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• 2004

In this study, a moment resisting precast concrete beam-column connection is proposed. An experimental study was carried out to investigate the connection behavior subjected to cyclic loading. Three precast beam-column interior connections and one monolithic connection were tested. Variable included the detailing used at the joint to achieve structural constructability and the location of mild steel reinforcement and high strength bar. During specimen fabrication, the joint details enables ease and speed of construction. Connection performance is evaluated on the basis of ductility, energy dissipation capacity, connection strength, and drift capacity. Based on test results, the precast concrete beam-column connection is capable of matching or exceeding the performance of the monolithic connection.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.213-216
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• 2006

The designer has difficulty due to inadequacy of provisions in the domestic design code and lack of understanding for behavior of D-region. The reinforced concrete pi(${\pi}$)-shaped RC rahmen bridge consists of various failure mechanisms as the crushing or splitting from compression concrete, and shearing failure under the loading plate. However, predicting those failure mechanisms is very difficult. In this study, the pi(${\pi}$)-shaped RC rahmen bridge is analyzed and designed by using strut-tie model. Adequacy for the application of strut-tie model is verified by comparison with the way used in current design practice. As a result that designing the structures should be maked a comparison between strut-tie model and current conventional design method.

• Computers and Concrete
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• v.13 no.4
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• pp.501-516
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• 2014

The purpose of this study was to investigate the performance of precast concrete pier cap system. The proposed precast pier cap provides an alternative to current cast-in-place systems, particularly for projects in which a reduced construction time is desired. Five large-scale pier cap specimens were constructed and tested under quasistatic monotonic loading. The computer program, RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology) was used for the analysis of reinforced concrete structures. A bonded tendon element is used based on the finite element method, and can represent the interaction between the tendon and concrete of a prestressed concrete member. A joint element is used in order to predict the inelastic behaviors of segmental joints with a shear key. This study documents the testing of the precast concrete pier cap system under monotonic loading and presents conclusions and design recommendations based on the experimental and analytical findings. Additional full-scale experimental research is needed to refine and confirm design details, especially for actual detailing employed in the field.

• Computers and Concrete
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• v.13 no.2
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• pp.221-234
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• 2014

A nonlinear finite element analysis using ANSYS is used to evaluate the seismic behavior of reinforced concrete exterior beam-column joints. The behavior of the finite element models under cyclic loading is compared with the experimental results. Two beam-column joint specimens (SH and SHD) with square hoop confinement in joint and throughout the column with detailing as per IS 13920 are studied. The specimen SHD was provided with additional diagonal bars from column to beam to relocate the plastic hinge formation from beam-column interface. The load-displacement relationship, joint shear stress and strain in beam obtained from numerical study showed good agreement with the experimental results. This investigation proves that seismic behaviour of reinforced concrete beam-column joints under reversed cyclic loading can be evaluated successfully using finite element modeling and analysis.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.305-312
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• 1999

A four-story reinforced concrete frame building model is designed for the gravity loads. only Static nonlinear pushover analyses are performed in two orthogonal horizontal directions. The overall capacity curves are converted into ADRS spectra and compared with demand spectra. At several points the deformed shape moment and shear distribution are calculated. It is observed that the seismic capacity may not meet the design requirements in soft soil condition and may collapse in MCE. It is concluded that limited but adequate amount of ductility need be provided in the seismic design in low to moderate seismicity regions.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.09a
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• pp.368-375
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• 2003

The objectives of this study were to provide experimental data on the behavior of interlocking spiral columns under cyclic loading, to compare the performance of columns with interlocking spirals to columns with U-type hoops with hook, to study the flexural detailing of interlocking spirals and other transverse steel configurations as the transverse reinforcement The oblong columns with interlocking spirals and with hooked U-type hoops and cross-ties better seismic performance than the rectangular columns with rectangular hoops and cross-ties. The oblong columns with hooked U-type hoops and cross-ties showed better seismic performance than the rectangular columns with rectangular hoops and cross-ties. And this research were to make recommendations for the design of bridge columns incorporating interlocking spirals and U-type hoops with hook as the transverse reinforcement.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.09a
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• pp.133-140
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• 2003

The objective of this study is to clarify the seismic capacity and the characteristics in the hysteretic behavior of RC structures with non-seismic detailing. Interior and exterior beam-column subassemblages were selected from a ten-story RC building and six 1/3-scale specimens were constructed with three variables; (1) with and without slab, (2) with and without hoop bars in the Joint region, (3) upward and downward direction of anchorage for the bottom bar in beams of exterior beam-column subassemblage. The test results have shown; (1) in case of interior beam-column subassemblage, there is no almost difference between nonseismic and seismic details in the strength and ductility capacity; (2) the Korean practice of anchorage (downward and 25 $d_{b}$ anchorage length) in the exterior Joint caused the 10％~20％ reduction of strength and 27％ reduction of ductility iii comparison with tile case of seismic details; and the existence of hoop bars in the joint region shows no effect in shear strain.n.

• Earthquakes and Structures
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• v.16 no.3
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• pp.253-263
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• 2019

The efficacy of a galvanized steel wire mesh (GSWM) as an alternative material for the rehabilitation of RC beam-column connections damaged due to reversed cyclic loading was investigated. The repair mainly uses epoxy resin infused under pressure into the damaged zone and then confined using three types of locally available GSWM mesh. The mesh types used herein are (a) Weave type square mesh with 2mm grid opening (GWSM-1) (b) Twisted wire mesh with hexagonal opening of 15 mm (GSWM-2) and (c) welded wire mesh with square opening of 25 mm (GSWM-3). A reduced scale RC beam-column connection detailed as per ductile detailing codes of Indian Standard was considered for the experimental investigation. The rehabilitated specimens were also subjected to similar cyclic displacement. Important parameters related to seismic capacity such as strength, stiffness degradation, energy dissipation, and ductility were evaluated. The rehabilitated connections exhibited equal or better performance and hence the adopted rehabilitation strategies could be considered as satisfactory. Confinement of damaged region using GSWM-1 significantly enhanced the seismic capacity of the connections.

• The Korean Journal of Mycology
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• v.48 no.4
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• pp.445-456
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• 2020

Fungal species belonging to the genus Penicillium are indigenous to a wide range of natural environments. Since the first published reports detailing the discovery of Penicillium, new species have been identified in various countries, including Korea. We present here a full characterization of five species of Penicillium that were previously unreported in Korea. Based on the morphologic characteristics and sequences of genes encoding fungal ��-tubulin and calmodulin, we identified five Penicillium species, including P. hetheringtonii, P. sublectaticum, and P. jacksonii, which have been unrecorded in Korea, and confirming P. maximae and P. cremeogriseum, as the endophytic fungi isolated in Gyeongsang province, Korea. In this article, we provide detailed morphological descriptions of these fungal species.