• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.8-9
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• 2021

FCP requires different curvatures and shapes according to the method of division, and it is necessary to manufacture a formwork accordingly. FCP production equipment consists of CNC equipment and side shape control equipment. This can be implemented in various shapes of upper, lower, and side surfaces. In the side shape control equipment, it is implemented as a variable side formwork. Among the required performance of the variable side formwork, there is stiffness against side pressure, which needs to be verified. Therefore, in this study, the FCP fabrication experiment is conducted with the developed variable side formwork. By analyzing the error in the shape of the fabricated FCP, the lateral pressure resistance capability of the side form is measured and verified.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.113-114
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• 2020

During the construction work, many deaths and injuries have occurred in the formwork. This study aims to analyze the perceptions of construction workers about the disaster of formwork collapse. In this study, the IPA(Importance-Performance Analysis) technique was used to analyze the perception of construction workers and derive urgent factors for improvement. As a result of IPA analysis, the fourth quadrant factor needed to be improved first, and the second quadrant factor needed effort distribution. Therefore, it is judged that this study can be used as basic data for safety management and disaster prevention activities.

• Journal of the Korean Society of Safety
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• v.21 no.3 s.75
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• pp.101-106
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• 2006

Formwork is a temporary structure that supports its weight and that of freshly placed concrete as well as construction live loads. In constructions site, pipe supports are usually used as shores which are consisted of the slab formwork. The strength of a pipe support is decreasing as it is frequently being used at the construction site. Among the accidents and failures that occur during concrete construction, there are many formwork failures which usually happen at the time concrete is being placed. The objective of this study is to find out the strength change of used pipe support and unused pipe supports according to aging. In this study, 2857 pipe supports were prepared. Among these pipe supports, 2337 pipe supports were lent to the construction companies free of charge. 520 pipe supports were kept on the outside. Compressive strength was measured by knife edge test and plate test at each 3 month. Test results show that the strength of unused pipe supports as well as used pipe supports was decreasing according to age, use frequency and load carrier, and the strength of used pipe supports was lower than the strength of unused pipe supports at the same age. So, the strength of used pipe supports from 191 days to present day was not satisfied the specification of KS F 8001. In this study, the strength of pipe support according to age, use frequency and load carrier was predicted using SPSS 12.0. It was known that the strength of pipe support using for 5 years was reduced to 42.8%. According to these results, it shows that attention has to be paid to formwork design using used pipe supports. Therefore, the present study results will be able to provide a finn base to prevent formwork collapses.

• Journal of the Korea Construction Safety Engineering Association
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• s.38
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• pp.79-87
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• 2006

Formwork is a temporary structure that supports its weight and that of freshly placed concrete as well as construction live loads. In constructions site, pipe supports are usually used as shores which are consisted of the stab formwork. The strength of a pipe support is decreasing as it is frequently being used at the construction site. Among the accidents and failures that occur during concrete construction, there are many formwork failures which usually happen at the time concrete is being placed. The objective of this study is to find out the strength change of used pipe support and unused pipe supports according to aging. In this study, 2857 pipe supports were prepared. Among these pipe supports, 2337 pipe supports were lent to the construction companies free of charge. 520 pipe supports were kept on the outside. Compressive strength was measured by knife edge test and plate test at each 3 month. Test results show that the strength of unused pipe supports as well as used pipe supports was decreasing according to age, use frequency and load carrier, and the strength of used pipe supports was lower than the strength of unused pipe supports at the same age. So, the strength of used pipe supports from 191 days to present day was not satisfied the specification of KSF 8001. In this study, the strength of pipe support according to age, use frequency and load carrier was predicted using SPSS 12.0. It was known that the strength of pipe support using for 5 years was reduced to 42.8%. According to these results, it shows that attention has to be paid to formwork design using used pipe supports. Therefore, the present study results will be able to provide a firm base to prevent formwork collapses.

• Journal of the Korean Society of Safety
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• v.20 no.3 s.71
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• pp.120-125
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• 2005

Formwork is a temporary structure that supports its weight and that of freshly placed concrete as well as construction live loads. Among the accidents and failures that occur during concrete construction, many are formwork failures which usually happen at the time concrete is being placed. In constructions site, pipe supports are usually used as shores which are consisted of the slab formwork. The strength of a pipe support is decreasing as it is frequently being used at the construction site. The objective of this study is to find out the strength change of used pipe support and unused pipe supports according to aging. In this study, 2857 pipe supports were prepared. Among these pipe supports, 2337 pipe supports were lent to the construction companies fire of charge. 520 pipe supports were kept on the outside. Compressive strength was measured by knife edge test and plate test at each 3 month. Test results show that the strength of unused pipe supports as well as used pipe supports was decreasing according to age, use frequency and load carrier, and the strength of used pipe supports was lower than the strength of unused pipe supports at the same age. So, the strength of used pipe supports from 191 days to present day was not satisfied the specification of KS F 8001. According to these results, it shows that attention has to be paid to formwork design using used pipe supports. Therefore, the present study results will be able to provide a firm base to prevent formwork collapses.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.499-505
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• 2021

The purpose of this study is to investigate experimentally the physical/chemical properties of concrete surface according to types of formworks. Plywood formwork and coated plywood formwork were prepared. In addition, plywood formwork with sand paper was prepared to simulate deterioration of concrete or rough surface of concrete. Normal concrete was used in this study. The properties of concrete surface were investigated by visual inspection, scanning electron microscopy and energy-dispersive X-ray spectroscopy techniques, elemental mapping, 2D and 3D surface profile measurement, and zeta potential measurement. Test results showed that concrete in a coated formwork had smooth surface and concrete in the formwork with sand paper had rough surface. It was observed that properties of concrete surface depended on types of formworks. Furthermore, differences in surface roughness were significantly higher than those in chemical compositions and zeta potential.

• Journal of the Korea Institute of Building Construction
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• v.22 no.2
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• pp.125-136
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• 2022

This research is to reduce the formwork leakage of high-fluidity concrete caused by insufficient accuracy of formwork fabrication widely used for high-fluidity concrete to general strength concrete. However, in the actual construction site, because of the insufficient accuracy of formwork fabrication may cause leaking concrete of mortar through a gab of the formwork. Therefore, in this research, which builds on previous research into providing thixotropy with PVA and Borax, the use of thixotropy to reduce high-fluidity mortar leakage was evaluated. The results of the experiment proved that the use of thixotropy with PVA and Borax can contribute to reduction of the formwork leakage of high-fluidity mortar. This finding is expected to lead to further research on reducing leakage of high-fluidity concrete.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1113-1116
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• 2009

The attempt to use a 3D model each field such as design, structure, construction, facilities, and estimation in the construction project has recently increased more and more while BIM (Building Information Modeling) that manages the process of generating and managing building data has risen during life cycle of a construction project. While the 2D Drawing based work of each field is achieved in the already existing construction project, the BIM based construction project aims at accomplishing 3D model based work of each field efficiently. Accordingly, the solution that fits 3D model based work of each field and supports plans in order to efficiently accomplish the relevant work is demanded. The estimation, one of the fields of the construction project, has applied BIM to calculate quantity and cost of the building materials used to construction works after taking off building quantity information from the 3D model by a item for a Quantity Take-off grouping the materials relevant to a 3D object. A 3D based estimation program has been commonly used in abroad advanced countries using BIM. The program can only calculate quantity related to one 3D object. In other words, it doesn't support the take-off process considering quantity of a contiguous object. In case of temporary materials used in the frame construction, there are instances where quantity is different by the contiguous object. For example, the formwork of the temporary materials quantity is changed by dimensions of the contiguous object because formwork of temporary materials goes through the quantity take-off process that deduces quantity of the connected object when different objects are connected. A worker can compulsorily adjust quantity so as to recognize the different object connected to the contiguous object and deduces quantity, but it mainly causes the confusion of work because it must complexly consider quantity of other materials related to the object besides. Therefore, this study is to propose the solution that automates the formwork 3D modeling to efficiently accomplish the quantity take-off of formwork by preventing the confusion of the work which is caused by the quantity deduction process between the contiguous object and the connected object.

• Korean Journal of Construction Engineering and Management
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• v.22 no.1
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• pp.81-89
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• 2021

In recent years, the design of buildings is changing from formal to creative and freeform. Accordingly, the scale of construction technology is changing to architectural design and construction of irregular buildings. Using the FDM method, which is one of the 3D printing technologies, it is possible to manufacture various forms of irregular formwork inexpensively and quickly coMPared to the existing formwork, and it seems to be able to solve the manpower problem. Using a 3D printer, the PLA filament formwork is produced in the form of a cylinder and a rectangular cuboid, and the usability of the PLA filament formwork is confirmed by examining the compression strength test and the degree of deformation and reusability over 28 days of age. Different sizes of additional specimens are also conducted according to the size. As a result of the experiment, it was confirmed that the filament formwork itself has about 3~4MPa strength. As a result of reviewing data through existing linear studies and experiments, it is appropriate to use more than 60% infill, and it is advantageous in terms of strength. As a result of cutting and dismantling the filament formwork, the surface is very clean and there is no damage, so it can be reused.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.6
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• pp.60-67
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• 2021

In lately, it's been developed and used a system of using deck plates as formwork in order to solve various problems caused by conventional formwork system. This system is more economical and has higher constructability than the conventional system by permanently embedding most of deck plates into the members. However, for this kind of embedded deck plates formwork system, it's been reported that it is difficult to verify filling of concrete in members like beams with narrow width and complicated rebar arrangement. In addtion, there are several problems such as corrosion of deck plates in terms of constructability and maintenance. Therefore, in this study, it is attempted to develop a removal-deck plate formwork system for beams by removing deck plates after concrete curing. The system consists of a deck plate module that acts as form, a frame preventing deformation by concrete lateral pressure, stirrup frame, and connector that combines these. As a result of this research, it is verified that it has higher constructability, efficiently prevents deformation caused by concrete lateral pressure and could be easily removed in the developed formwork system.