• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.29-30
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• 2012

The precast concrete column-beam structure, Green Frame, allows the main structural members such as precast concrete column and beam to be produced on the site, resulting in a reduction of transportation cost and the margin of plant. However, existing plywood from for in-situ production of precast concrete members has problems like putting in inordinate human resource, falling-off in quality and workability. To solve those problems, form system for in-situ production of precast concrete members shall be developed. In this regard, this study aims to analyze the structural concept of from system for in-situ production. The result of this study will use for development of form system for in-situ production.

• Journal of the Korea Institute of Building Construction
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• v.11 no.5
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• pp.501-514
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• 2011

Recently, there have been many cases in which the difficulty of repair and replacement of principal elements in the bearing wall structure for apartment buildings, which is a major part of apartment buildings in Korea, has led to the reconstruction of buildings rather than their remodeling. To address this problem, the Korea government now allows a floor area ratio of up to 20 %, and has relaxed the building height limits to encourage the use of a rahmen structure instead of a bearing wall structure. However, since reinforced concrete rahmen structures have many problems, including higher floor height and greater construction cost, a great deal of research into rahmen composite precast concrete structures have been conducted. Green Frame, one of the developed prototypes, is expected to provide economic benefits through in-situ production for precast concrete column and beam. For in-situ production of composite precast concrete members, a detailed plan for production, curing, and installation is needed. However, it needs to be confirmed that the space is sufficient to produce the precast concrete members on-site before planning those activities. Therefore, this study proposes in-situ production analysis of composite precast concrete members of Green Frame with the evaluation of structural safety and available area on the parking structure. The result of this study shows that the in-situ production of precast concrete members is possible through a case study.

• Computers and Concrete
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• v.16 no.4
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• pp.643-667
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• 2015

3-dimentional precast recycled aggregate concrete (RAC) finite element models were developed by means of the platform OpenSees to implement sophisticated nonlinear model subjected to seismic loads. Efforts were devoted to the dynamic responses (including dynamic characteristics, acceleration amplifications, displacements, story drifts) and capacity curve. In addition, this study extended the prediction on dynamic response of precast RAC model by parametric study of material properties that represent the replacement percentage of recycled coarse aggregate (RCA). Principles and assumptions that represent characteristics of precast structure and influence of the interface between head of column and cast-in-place (CIP) joint on the stiffness of the joints was put forward and validated by test results. The comparison between simulated and tested results of the precast RAC frame shows a good correlation with most of the relative errors about 25% in general. Therefore, the adopted assumptions and the platform OpenSees are a viable approach to simulate the dynamic response of precast frames made of RAC.

• Steel and Composite Structures
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• v.10 no.1
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• pp.1-21
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• 2010

As an alternative for conventional structures for tall buildings, a hybrid lateral load resisting structure has been designed, enabling the assembly of tall buildings directly from a truck. It consists of steel frames with discretely connected precast concrete infill panels provided with window openings. Besides the stiffening and strengthening effect of the infill panels on the frame structure, economical benefits may be derived from saving costs on materials and labour, and from reducing construction time. In order to develop design rules for this type of structure, the hybrid infilled frame has recently been subjected to experimental and numerical analyses. Ten full-scale tests were performed on one-storey, one-bay, 3 by 3 m infilled frame structures, having different window opening geometries. Subsequently, the response of the full-scale experiments was simulated with the finite element program DIANA. The finite element simulations were performed taking into account non-linear material characteristics and geometrical non-linearity. The experiments show that discretely connected precast concrete panels provided with a window opening, can significantly improve the performance of steel frames. A comparison between the full-scale experiments and simulations shows that the finite element models enable simulating the elastic and plastic behaviour of the hybrid infilled frame.

• Computers and Concrete
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• v.22 no.4
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• pp.383-393
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• 2018

Infill wall strengthening method has been widely used for seismic strengthening of deteriorated reinforced concrete (RC) frame structures with non-seismic details. Although such infill wall method can ensure sufficient lateral strengths of RC frame structures deteriorated in seismic performances with a low constructional cost, it generally requires quite cumbersome construction works due to its complex connection details between an infill wall and existing RC frame. In this study, an advanced seismic strengthening method using externally-anchored precast wall panels (EPCW) was developed to overcome the disadvantage inherent in the existing infill wall strengthening method. A total of four RC frame specimens were carefully designed and fabricated. Cyclic loading tests were then conducted to examine seismic performances of RC frame specimens strengthened using the EPCW method. Two specimens were fully strengthened using stocky precast wall panels with different connection details while one specimen was strengthened only in column perimeter with slender precast wall panels. Test results showed that the strength, stiffness, and energy dissipation capacity of RC frame specimens strengthened by EPCWs were improved compared to control frame specimens without strengthening.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.176-177
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• 2013

The composite PC rahmen structure, called Green Frame, allows the main structural members such as PC column and beam to be produced on the site, resulting in a reduction of PC member transportation cost and the margin of PC plant (operation cost and profit), making it more economic than the bearing wall structure. To apply the Green Frame to practice, not only installation but also insitu-production process should be considered. Therefore, this study analyse the influence factors on insitu-production and installation schedule of composite precast concrete members. The results shall be used as basic criteria on the planning of insitu-production and installation of Green Frame.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.14-15
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• 2018

Logistics facilities are characterized by wide spans and high flooring, most of which are constructed with PC (Precast Concrete) methods to meet a wide range of commercial and industrial needs. However, the PC structure is a pin joint design, and the construction cost is increased due to the restrictions caused by the installation process, and the construction period is lengthened. In order to solve the above problem, SMART Frame, which is a structural system similar to the steel frame structure, was developed by embedding a steel frame at both ends of the PC. The purpose of this study is to analyze the erection time reduction effect of steel connected precast concrete components (SMART frames) for long span and heavy loaded logistics buildings compared to existing PC frames. For this study, a logistics building constructed with pin joint PC components is selected as a case. The result is compared with the existing PC frame to confirm the erection time reduction effect.

• International journal of steel structures
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• v.18 no.5
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• pp.1666-1683
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• 2018

To explore seismic behavior of blind bolted concrete-filled steel tube (CFST) frames infilled with precast sandwich composite wall panels (SCWPs), a series tests of blind bolted square CFST frames with precast SCWPs under lateral low-cyclic loading were conducted. The influence of the type of wall concrete, wall-to-frame connection and steel brace setting, etc. on the hysteretic curves and failure modes of the type of composite structure was investigated. The seismic behavior of the blind bolted CFST frames with precast SCWPs was evaluated in terms of lateral load-displacement relation curves, strength and stiffness degradation, crack patterns of SCWPs, energy dissipation capacity and ductility. Then, a finite element (FE) analysis modeling using ABAQUS software was developed in considering the nonlinear material properties and complex components interaction. Comparison indicated that the FE analytical results coincided well with the test results. Both the experimental and numerical results indicated that setting the external precast SCWPs could heighten the load carrying capacities and rigidities of the blind bolted CFST frames by using reasonable connectors between frame and SCWPs. These experimental studies and FE analysis would enable improvement in the practical design of the SCWPs in fabricated CFST structure buildings.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.10-11
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• 2013

Green Frame is a column-beam system formed by composite precast concrete column and beam connected with steel buried in both members. During the installation of Green columns, the columns of Green Frame, covering 3 floors per each piece and beams, the eccentricity can be observed due to the construction error and the weight of beam itself. Such eccentricity may have a little influence on a single frame, yet, it can develop critical issues to the installation of subsequent beams or beams on the upper floors in the context of a building as a whole that has multiple frames. These issues lead to delay in frame installation, decrease of productivity and increase of cost, etc. Therefore, this study presents a steel-joint connection method in order to solve the issues. The steel-joint connection method exists on slope plane and reinforcing plate in steel frame buried in composite PC members. Through this method, the issues can be resolved without requiring additional equipment or manpower.

• Steel and Composite Structures
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• v.19 no.6
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• pp.1403-1419
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• 2015

When precast concrete infill panels are connected to steel frames at discrete locations, interaction at the structural interface is neither complete nor absent. The contribution of precast concrete infill panels to the lateral stiffness and strength of steel frames can be significant depending on the quality, quantity and location of the discrete interface connections. This paper presents preliminary experimental and finite element results of an investigation into the composite behaviour of a square steel frame with a precast concrete infill panel subject to lateral loading. The panel is connected at the corners to the ends of the top and bottom beams. The Frame-to-Panel-Connection, FPC4 between steel beam and concrete panel consists of two parts. A T-section with five achor bars welded to the top of the flange is cast in at the panel corner at a forty five degree angle. The triangularly shaped web of the T-section is reinforced against local buckling with a stiffener plate. The second part consists of a triangular gusset plate which is welded to the beam flange. Two bolts acting in shear connect the gusset plate to the web of the T-section. This way the connection can act in tension or compression. Experimental pull-out tests on individual connections allowed their load deflection characteristics to be established. A full scale experiment was performed on a one-storey one-bay 3 by 3 m infilled frame structure which was horizontally loaded at the top. With the characteristics of the frame-to-panel connections obtained from the experiments on individual connections, finite element analyses were performed on the infilled frame structures taking geometric and material non-linear behaviour of the structural components into account. The finite element model yields reasonably accurate results. This allows the model to be used for further parametric studies.