• Korean Journal of Construction Engineering and Management
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• v.22 no.2
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• pp.53-62
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• 2021

PC component allocation and loading plan can contribute to reductions in carbon dioxide emission and energy use of vehicles and total project costs with increased utilization of vehicle loading space. The study derived 18 considerations that PC construction plant managers and site managers take into account when they plan allocation and loading of PC components. Then, IPA (Importance and Performance Analysis) was performed to assess importance and performance of the 18 considerations. Results show that in the PC component allocation planning, considerations regarding the number of vehicles and existence of yard for storing PC components have not been taken into account well by the managers. In the PC component loading planning, PC component loading direction has not been reflected well by the managers although it is considered important by them. Recently, ill-planning issues of PC component transportation, such as inefficient use of vehicle space and loading with low stability, are frequent due to various types of PC components produced. In this context, if the results of this study are reflected in the development of component allocation and loading planning, vehicle management of PC projects would be more efficient, thereby leading to economic project management.

• Korean Journal of Construction Engineering and Management
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• v.24 no.4
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• pp.52-59
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• 2023

Flatness inspection of PC elements is normally conducted manually by inspectors at manufacturing sites. However, the manual inspection is error-prone and subjective, so it is necessary to develop a robust and efficient flatness measurement method. Recently, a few studies of laser scanner-based flatness inspection have been conducted. However, little attention on field applicability in terms of accuracy, time and cost has been paid. To tackle the limitation, this study aims to compare three sensing method including floor profiler, terrestrial laser scanner and total station for flatness inspection of PC elements. A series of experiments on two full-scale PC slabs were conducted and the results show that the laser scanning method is the most suitable for the PC elements flatness inspection in the aspects of accuracy, time and cost.

• Land and Housing Review
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• v.5 no.2
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• pp.91-97
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• 2014

An experimental program was initiated to investigate the structural capacity of PC (Precast Concrete) beam-column joints used for the underground parking structure. Static testing of 4 typical PC beam-column joints specimens was conducted. Specimens were designed to span a range of parameters typically encountered for such members, based on findings from the survey of existing PC joint details used in the construction fields in Korea. The specimens were four by their joint types and testing parameters. The specific structural behavior germane to each specimen, and general observations on overall member behavior as a function of the considered parameters, are reported. From the results of tests on four PC joints specimens, the beam-column joints of PC structure used for the underground parking building was found to have similar structural capacities when comparing to the cast-in-place concrete system.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.1
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• pp.55-64
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• 1999

Large size shipyards have peformed the generating of piece and the nesting using shipbuilding-oriented CAD program, which requires higher skilled operators and lots of costs. So, medium and small size shipyards have pursued different types of piece generation and nesting (arrangement method). This research is to develop a program for the generating of pieces with parametric macro method and a STRIP program for the nesting of pieces by PC, which can be applied in such shipyards.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.233-234
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• 2023

This paper confirms the application sites of dry coupler technology, which is a direct connection method using screw threads, and Unlike wet couplers, this method can stand on its own without proof support and continuous work on the upper part. Furthermore, concludes with personal considerations to improve constructability.

• Korean Journal of Construction Engineering and Management
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• v.23 no.6
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• pp.89-100
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• 2022

The development of the Construction Production Rates System for appropriate construction cost calculation has recently come to the fore as a means of invigorating OSC based PC structure which currently needs institutional frameworks. PC structure based construction expenses consist of the factory-built assembly, transportation and on-site installation. Recently, in the field of transportation and site installation, research on product structure development is being conducted, such as presenting the standard product calculation system reflecting the results of field survey for each subsidiary materials (Lee et al., 2021). On the other hand, there is no ongoing research on estimating construction expenses of Factory-built assembly. This study suggests Construction Production Rates System which can be used for PC subsidiary materials based Factory-built assembly cost estimations. For the research, work types for the construction procedures have been categorized, and the standard input manpower suitable for the corresponding work characteristics has been derived from analyzing the associated Construction Standard Production Rates for each work type. Also, as the research referred PC subsidiary materials (such as columns, beams, walls, and slab, as well as on-site installation) and the standard number of workforce based on work types, one can calculate direct labor cost, using what the research shows. In addition, it suggests that the size of individual subsidiary materials be the extra cost factor, by using the characteristics that productivity changes depending on the size(m³) of subsidiary materials. It is expected that the research can contribute to objectively verifying factory-built assembly cost through of PC structure, which currently relies on estimates.

• Korean Journal of Construction Engineering and Management
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• v.22 no.6
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• pp.96-106
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• 2021

The PC structure based on the OSC (Off-Site Construction) is mentioned as a representative method of innovation in the construction industry that converts the existing construction environment from site-centered to factory production-transportation-site assembly. However, recent research on PC method has focused on improving the functions of subsidiary materials and improving the production system to increase productivity and institutional / policy R&D that can be universally applied to the life-cycle stage of ordering / design /construction is insufficient. In particular, the absence of standardized cost calculation standards makes it difficult to calculate and verify of objectified appropriate construction cost. So which is an obstacle to the activation of the PC method. In this study, the standards for construction costs of domestic and foreign PC method were surveyed and similar Construction Standard Production Rates were analyzed to confirm the product structure suitable for PC method. Subsequently, the construction procedures and input resources for each PC subsidiary materials were identified through on-site surveys to derive component for subsidiary materials, and the factors of change in the product according to the construction characteristics(height, weight of subsidiary material) were verified. As a result the standard product calculation system suitable for the site installation of the PC method for apartment was presented.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.77-78
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• 2023

As large logistics buildings have high floor heights and long spans, these buildings are designed as PC structures, and large cranes are used to lift PC members. PC erection planning can generally cause errors depending on the field engineer's experience. To solve this problem, a basic analysis method is needed to establish a systematic PC member erection plan. Crane work can be minimized if the trajectory is easily and quickly calculated according to the location of the crane and applied to the site. Therefore, the objective of this study is a basic study of crane trajectory distance calculation for sustainable PC members erection of large logistic building. In this study, a crawler crane commonly used for lifting PC members is limited. The trajectory distance for the PC erection plan was automatically calculated using the algorithm.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.117-118
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• 2023

Estimating the construction period at the initial stage of the project and determining whether it is appropriate is very important for the developer's decision-making and the success of the construction company's business. Existing researchers have conducted various studies to calculate the appropriate construction period, but there is no study on the influencing factors and methodology for the construction period of beam-column PC apartment building frame construction. The purpose of this study is to calculate the PC member assembly time using the mathematical algorithm of PC member assembly. The results of this study can be used as basic data to calculate the construction date of the standard floor of PC construction.

• Journal of the Korea Institute of Building Construction
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• v.14 no.6
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• pp.571-581
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• 2014

In the present study, hollow precast concrete wall (PC Double Wall) for staircase construction was developed. Comparing the conventional walls, the PC Double Wall can be reduced the lift weight using hollow core and improves the integrity between the PC members. The cross-section and re-bar details of the PC Double Wall were developed considering precast concrete manufacturing, constructability, and the structural safety. Particularly, a form system was developed to manufacture thin and hollow core PC wall efficiently. A mock-up test for a staircase using the PC Double wall was performed to verify the constructability and integrity of the PC walls. The test result verified that joint deformation and cracking did not occur as showing good constructability.