• Structural Engineering and Mechanics
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• v.71 no.4
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• pp.341-350
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• 2019

Exterior beam-column joint is typically the weakest link in a limited-ductile reinforced concrete (RC) frame structure. The use of diagonal haunch element has been considered as a desirable seismic retrofit option for reducing the seismic demand at the joint. Previous research globally has focused on implementing double haunches, while the use of single haunch element as a less-invasive and more architecturally favorable retrofit option has not been investigated. In this paper, the key formulations and a design procedure for the single haunch system for retrofitting RC exterior beam-column joint are developed. An application of the proposed design procedure is then illustrated through a case study.

• 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.

• Computers and Concrete
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• v.23 no.3
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• pp.203-215
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• 2019

Precast reinforced concrete structure (PRCS) consists of prefabricated members assembled at worksites and has more connections limitations in comparison with the equivalent in-situ reinforced concrete structure (IRCS). As a result of these limitations, PRCSs have less ductility in comparison with IRCSs. Recent studies indicate that the most noticeable failure in PRCSs have occurred in their connection zone. The objective of this study is introducing a type of precast beam-to-column connection (PBC) which in spite of being simple is of the same efficiency and performance as in-situ beam-to-column connection (IBC). To achieve this, the performance of proposed new PBC at exterior joint of a four story PRCS was analyzed by pseudo dynamic analysis and compared with that of IBC in equivalent IRCS. Results indicated that the proposed connection has even better performance in terms of strength, energy dissipation and stiffness, than that of IBC.

• Structural Engineering and Mechanics
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• v.85 no.3
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• pp.353-367
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• 2023

An extended parametric study based on nonlinear finite element analyses is performed to assess the key factors affecting the shear behaviour of exterior beam-column joints of unbraced reinforced concrete frames. Extensive results are presented, the major conclusion being that the few shear behaviour models for exterior reinforced concrete beam-column joints available in the literature do not properly account for some of the most influential factors. The present results are also compared with recently published results for interior joints, showing that while some factors have a similar influence on interior and exterior joints others are relevant for only one of these types of joints. This also confirms, numerically, that some resisting mechanisms of exterior joints differ from those of interior joints.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.41-42
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• 2022

This study analyzed the process related to the linkage between on-site work targeting the middle size Precast Concrete(PC) public apartment building with beam-column system and prepared on-site works flow relationship diagram in which the wet process consists of core Critical Path(CP) to prepare a network diagram of the Precedence Diagram Method(PDM). Through this study, it is expected that it will be possible to maximize the project management capability by suggesting a method to minimize risk factors and the optimized process management of the beam-column system PC public apartment building.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.553-556
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• 1999

In this dissertation, experimental research was carried out to study the hysteretic behavior of reinforced high-strength concrete beam-column joints designed by high performance techniques, such as application of high-strength concrete, reducing of joint regions damage, moving of beam plastic hinge. Specimens(HJAI, HJCI), designed by the development of earthquake-resistant performance, moving of beam plastic hinge, and new design approach, were attained the moving of beam plastic hinge and developed significantly earthquake-resistant performance of such joints.

• 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.

• Steel and Composite Structures
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• v.25 no.4
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• pp.443-456
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• 2017

Many authors have established the usefulness of concrete filled steel tubular (CFST) sections as compression members while few have proved their utility as flexural members. To explore their prospective as part of CFST frame structures, two types of connections using extended end plate and seat angle are proposed for exterior joints of CFST beams and CFST columns. To investigate the performance and failure modes of the proposed bolted connections subjected to static loads, an experimental program has been executed involving ten specimens of exterior beam-to-column joints subjected to monotonically increasing load applied at the tip of beam, the performance is appraised in terms of load deformation behaviour of joints. The test parameters varied are the beam section type, type and diameter of bolts. To validate the experimental behaviour of the proposed connections in CFST beam-column joints, finite element analysis for the applied load has been performed using software ATENA-3D and the results of the proposed models are compared with experimental results. The experimental results obtained agree that the proposed CFST beam-column connections perform in a semi-rigid and partial strength mode as per specification of EC3.

• Steel and Composite Structures
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• v.45 no.2
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• pp.231-248
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• 2022

Hybrid Steel-Trussed Concrete Beam (HSTCB) is structural typology suitable for light industrialization. HSTCBs usually cover long span with small depths, which lead to significant amount of longitudinal rebars. The latter make beam-column joints more prone to damage due to earthquake-induced cyclic actions. This phenomenon can be avoided using friction-based BCCs. Friction devices at Beam-to-Column Connections (BCCs) have become promising solutions to reduce the damage experienced by structural members during severe earthquakes. Few solutions have been developed for cast-in-place Reinforced Concrete (RC) and steel-concrete composite Moment Resisting Frames (MRFs), because of the difficulty of designing cost-effective damage-proof connections. This paper proposes a friction-based BCC for RC MRFs made with HSTCBs. Firstly, the proposed connection is described, and its innovative characteristics are emphasized. Secondly, the design method of the connection is outlined. A detailed 3D FE model representative of a beam-column joint fitted with the proposed connection is developed. Several monotonic and cyclic analyses are performed, investigating different design moment values. Lastly, the numerical results are discussed, which demonstrate the efficiency of the proposed solution in preventing damage to RC members, and in ensuring satisfactory dissipative capacity.

• Proceedings of the Korean Geotechical Society Conference
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• 1996.03a
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• pp.119-132
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• 1996