• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.12-13
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• 2020

Free-form buildings usually have large curved shapes on the outside. In order to construct this curved shape, the exterior of the building must be divided into easy-to-manufacture shapes, and the segmented panel is called the FCP(Free-form Concrete Panel). These FCPs have different shapes and cannot reuse molds. To solve these problems, the researchers developed FCP manufacturing equipment to manufacture a mould of FCP. However, the developed equipment alone cannot completely manufacture FCP's mould. This is because there is no mould to implement side of FCP. Therefore, it is necessary to develop a side form of FCP that can be applied to FCP manufacturing equipment. To this end, this study analyzes the basic requirements that side mould should have before developing side mould.

• Journal of the Korea Institute of Building Construction
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• v.20 no.2
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• pp.155-162
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• 2020

Since the third industrial revolution has been started in the 1980s, the form of buildings has been varied and atypical by the development of building technology. Such free-form building has a curved shape unlike the existing standard buildings, and to realize this, it is necessary to manufacture the free-from panel. The shape of the free-form panel must satisfy a limited error ratio compared with the design shape, and the technology to produce free-form panels is very difficult. However, there are many problems such as enormous cost and construction waste generation when implementing free-from construction. Therefore, the development of free-form panel manufacturing technology should be made to solve the problems caused by the free-form construction. In this study, the error rate analysis of the mixed mortar panel was conducted by selecting the proper mixing ratio of the mixed mortar for the shape of the free-form panel.

• Korean Journal of Construction Engineering and Management
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• v.15 no.4
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• pp.95-106
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• 2014

The outer surfaces of free form buildings contain panels with two-directional curvatures. To construct these panels, complex geometric surfaces should be divided into forms and sizes that can be manufactured and constructed efficiently. Because the bigger the curvatures of these panel, the more expensive the construction costs, these complex curvatures should go through optimal process of reinterpretation to minimize the curved surfaces with complex two-directional curvatures, which is called panel optimization. Small construction and design companies have trouble in calculating even rough estimate and cannot adjust expected construction cost of the panels based on comparison of design alternatives in conjunction with panel optimization process due to lack of knowledge and experience. This study conducts the research that can support designers' cost decision-making in the design stage of the free form buildings with respect to the panel optimization process. A 3D commercial application specialized to modeling free form shapes is used for the purpose.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.401-404
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• 2015

Demand on free-form buildings is gradually increasing, yet owing to the difficulty of production-installation work, several problems occur in the construction phase upon construction of a building, including the increased cost and construction duration, and reduced constructibility. To solve these problems, a techonology to produce FCP using a CNC(Computerized Numeric Control) machine is developed. The technology is that the information of designed free-form buildings to the CNC machine is transferred, and the transferred information is used for RTM(Rod-Type Mold, the mold shaped by back-up rods) and PCM(Phase Change Material) shaping, and the shaped RTM and PCM have the role of molds to produce FCP. Construction duration and project cost are limited in building sites, so the efficiency of processes like production-installation of FCP for application of the technology is significant. Since it is almost impossible to change the production-installation process at the construction phase when they are established, process should be deliberately decided. Therefore, the purpose of the study is to propose a production-installation simulation model of free-form concrete panels, in aspect of PCM. This paper is establishing the process for production-installation of FCP, estimating time required by each construction type and proposing a time simulation model that changes according to various constraints based on the analyses. With the time simulation model, it will be possible to build a cost model and to review the optimal construction duration and project cost.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.341-345
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• 2006

zArchitect Kim lung-up used free-curved lines as his architectural language. We can categorize his language into 'overlapped curved lines' and 'juxtaposed circles.' We found that his language was expressed well when he applied a specific material, for example, overlapped curved lines - concrete and juxtaposed circles - brick. Furthermore, using the plasticity of concrete, he built roofs and columns in a curved form. He also created reliefs on the walls out of the characteristics of bricks. It can be evidence that he considered forms and characteristics of materials to design buildings. This research mainly focuses on his design method to use free-curved lines with specific materials based on the analyses of forms and materials applied in his architecture buildings and art works

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.133-134
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• 2023

Free-form buildings have a curved shape and are composed of geometric shapes, which require high precision. Therefore, this study proposed a new extrusion method, a piston method, that improves the precision of FCP by automatically extruding a predetermined amount of concrete by improving the aforementioned limitations. The technology to extrude a predetermined amount of concrete by applying pistons is expected to shorten construction period and increase economic efficiency by improving the precision and productivity of free-form panels.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.333-340
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• 2018

Recently, free-form buildings have been designed with complex shapes due to digitization of the construction industry. Exterior and interior components of free-form buildings have free cross sections and curved shapes. Therefore, structural members with curvature are frequently seen. In the modeling and stability evaluation of these structures, commercial programs using classical finite element analysis are not able to perform rapid shape modeling, resulting in a decrease in productivity. Therefore, in this study, pre- and post-processing modules were developed using a prior study to rapidly model the surface of a free-form building and to automatically generate frame structures that make up the cladding. The developed modules use a subdivision algorithm with spline curves. This algorithm is used to automatically generate analytical elements from the configuration information of NURBS curves. In addition, the deformation after analysis can be viewed more realistically. The modules can quickly construct complex curved surfaces. An analysis model of the frame structure was also automatically generated. Therefore, the modules could contribute to the productivity improvement of free-form building design.

• International Journal of High-Rise Buildings
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• v.5 no.4
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• pp.243-250
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• 2016

Today's architectural design trend based on the recognition of pluralism has led to multiple design directions for all building types including tall buildings. This contemporary design trend has produced many complex-shaped tall buildings, such as twisted, tilted, tapered and freeform towers. Among many different structural systems developed for tall buildings, the diagrid system, with its powerful structural rationale and distinguished aesthetic potential, is one of the most widely used systems for today's tall buildings. This paper studies structural performance of diagrid systems employed for complex-shaped tall buildings. Twisted, tilted, tapered and freeform tall buildings are designed with diagrid structures, and their structural performances are investigated. For the twisted diagrid study, the buildings are twisted up to 3 degrees per floor. In the tilted diagrid study, the angles of tilting range from 0 to 13 degrees. The impact of eccentricity is investigated for gravity as well as lateral loads in tilted towers. In the study of tapered diagrid structures, the angles of tapering range from 0 to 3 degrees. In the study of freeform diagrid structures, lateral stiffness of freeform diagrids is evaluated depending on the degree of fluctuation of free form. The freeform floor plans fluctuate from plus/minus 1.5 meter to plus/minus 4.5 meter boundaries of the original square floor plan. Parametric structural models are generated using appropriate computer programs and the models are exported to structural engineering software for design, analyses and comparative studies.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.121-122
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• 2015

The demand on free-form buildings is gradually increasing, but there are several problems such as increased cost and construction duration, and decreased constructability at the construction phase upon construction of a building owing to the difficulty of member production-installation. To solve these problems, a technology to produce FCP using a CNC machine was developed. Basically, it delivers the information on a free-form building designed to the CNC machine, the shapes of RTM and PCM are created using the information delivered and FCP are produced with the RTM and PCM which act as forms. Since the construction duration and project cost are limited on site, the efficiency of FCP production-installation is significant for application of the technology. For it is almost impossible to change the production-installation layout and process once they are set in the construction phase, they should be carefully determined. Before the production-installation layout are established, it is necessary to analyze the factors that influence the duration. Thus, the study intends to analyze influence factors in PCM mold on estimation of the production-installation duration for FCP. According to the analysis of influence factors, a simulation model for estimation of the duration that changes depending on the constraint conditions can be built.

• Journal of the Korea Institute of Building Construction
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• v.19 no.5
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• pp.449-456
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• 2019

Recent developments in architectural technologies and programs have enabled architects to think creatively and design free-form architecture. however, there are many problems in the production technology of FCP(Free-Form Concrete Panel). In particular, reduced accuracy due to lack of free-form panel production technology can lead to redesign of buildings as a result, problems such as an increase in construction cost and period. Therefore, this experiment aimed to compensate the decrease of the accuracy according to the displacement difference and to derive the proper mixing ratio for maintaining the shape during the free-form panel curing. In this study, molds were made using paraffin that is a recyclable phase change material. Concrete Panel is usually produced from Portland cement, dead burn magnesia, phosphate, borax and fine aggregate. In this study, four mixing ratios of FCP were selected after each material was blended to determine the proper blending ratio of the fluidity phase, the water absorption rate and the water content of the test piece. FCP was fabricated on the basis of the selected four compounding ratios and thickness and error rate were measured. Based on the error rate of the measured FCP, the quality standard was satisfied among the four compounding ratios.