• Journal of the Korea Institute of Building Construction
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• v.10 no.2
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• pp.125-132
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• 2010

Recently, construction companies have had difficulty in managing their business due to economic hardship domestically and abroad, decreased orders, and low profitability due to intensified competition. To address these issues, construction companies need to develop or introduce construction methods that improve productivity. The purpose of this study is to investigate a re-bar construction method that reduces the high expenses of transport by folding a pre-fabricated re-bar cage. It was concluded that the application of rebar pre-fabrication would be activated and the productivity of construction sites improved by adopting the folding rebar pre-fabrication method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.81-88
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• 2018

The present study evaluated the effective arrangement approach of transverse reinforcement in the jacket section for seismic strengthening of reinforced concrete columns. To simulate the full-scale columns, the section dimensions were determined as $450{\times}450mm$ for non-seismic existing columns and $750{\times}750mm$ for section enlargement strengthening columns. Over-lapped channel-shape bars and prefabricated bar units were proposed for closed-hoops in the jacket section, and conventional cross-ties anchored into existing columns and V-ties were considered for the supplementary ties. Test results showed that the axial capacity of the existing column and section enlargement columns with over-lapped channel-shape hoops was similar to the nominal strength calculated using ACI 318-14 procedure whereas the section enlargement column with prefabricated bar units possessed 1.25 times higher axial capacity than the nominal prediction. Furthermore, the axial ductility ratio of the section enlargement column with prefabricated bar unit was 139% higher than that of the existing column despite the potential size effect on ductility of concrete. Thus, it can be concluded that the developed prefabricated bar unit technique is practically useful for preventing the premature buckling of longitudinal reinforcement and confining core concrete in the section enlargement strengthening columns.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.12-13
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• 2018

Reinforced concrete works account for 40 to 50 percent of the total construction work. However, the shortage of construction workers is a problem in the delay of the construction period of reinforced concrete. The partial rebar prefabrication is one of the ways to shorten construction period. Thus, this study compared the partial rebar prefabrication and field fabrication method through work sampling. As a result, the partial rebar prefabrication showed a significant decrease in time compared to field fabrication method. As a result of this study, it is expected to be used as a reference for the efficient selection of reinforced concrete methods.

• Magazine of the Korea Concrete Institute
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• v.28 no.5
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• pp.43-47
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• 2016

• Magazine of the Korea Concrete Institute
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• v.16 no.1 s.78
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• pp.91-95
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• 2004

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.76-77
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• 2015

In construction industry, management of construction factors such as cost, schedule, quality and safety is the most important key for delivering successful projects. According to the Smart Market Report, a magazine specialized in construction industry, recently said 'Off-site Prefabrication' is a significant trend related with construction productivity in global construction industry. It is a kind of practice shift from On-site to Off-site. A lot of general contractors in oversea have been using 'Multi-trade MEP Ceiling Rack Prefabrication' method for getting benefits such as decreased cost & schedule and increased labor productivity. Thus, in this paper, critical management factors at each phase from design to installation was derived by researching case studies. Forwardly, it can be a basic guideline for applying Multi-trade MEP Ceiling Rack Prefabrication in Korea construction industry.

• Journal of Korean Association for Spatial Structures
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• v.16 no.2
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• pp.18-23
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• 2016

• Journal of Korean Association for Spatial Structures
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• v.20 no.2
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• pp.11-18
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• 2020

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.8-9
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• 2019

The rebar work is a labor intensive construction work with a high labor cost ratio. It is difficult to manage the productivity, construction time, and safety of rebar work. The problem of productivity decreased in rebar construction is due to a lack of workers according to the aged workers. Partial prefabrication rebar can be an alternative solution to productivity decreased in rebar work. The characteristic of partial prefabrication method is that time consuming component such as stirrup of beam assemble in factory and others assemble in site. Therefore, in this study, the time required for each rebar assembly method is measured and analyzed to confirm the possibility of productivity improvement.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.159-160
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• 2019

Reinforced concrete construction is one of the labor intensive construction projects and its productivity is very low. It is necessary to increase the productivity of rebar construction for improving the productivity of construction work. Therefore, in this study, the rebar drawings of apartment buildings are analyzed to prefabricate wall rebar unit shaped mesh in the factory and installing it on site. If the proposed wall rebar unit is applied to apartment construction working time of wall rebar can be reduced by 50% or more.