• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.293-294
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• 2023

In accordance with recent changes in construction trends, interest in introducing the OSC, such as the Precast Concrete, is increasing in apartment buildings. In domestic studies, studies on the prediction of the construction period of PC apartment buildings through simulation have been conducted, but there is no study on the comparison of the construction period according to the actual construction of Precast Concrete(PC) and Reinforced Concrete(RC). Therefore, this study seeks to grasp the technology of the current PC construction method and to secure the original technology of project management through comparison of the absolute time of frame construction for PC and RC buildings composed of the same plane.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.21-23
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• 2010

This study was conducted to draw various decisive elements of a reasonable heat curing method and to examine the importance in deciding a construction method when constructing cold weather concrete. As a result, the items proposed as important elements at the time of decision of a heat curing method included economy, workability, maintainability, insulation capability, reduced construction period and usability. As a result of importance by items under AHP technique, it was found the most important element was insulation capability, followed by reduced construction period and workability. As a result of comparison of a heat supplying and a heat insulation method by dual bubble sheet differed 2 times as much as a heat supplying method, especially the evaluation degree by insulation capability and reduced construction period was high.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.87-88
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• 2023

In accordance with changes in the domestic construction environment, interest in off-site construction methods (factory-manufactured construction methods) including modular construction methods is rapidly increasing. Among various off-site (OSC) construction methods, the front runner is the steel-based box-type modular construction method. Compared to the existing wet construction method, the steel modular construction method is increasing in terms of securing economic feasibility by shortening the construction period and increasing the prefabrication rate. However, due to the recent rise in raw materials and a sharp rise in the exchange rate, the economic feasibility of the wet method is deteriorating compared to the wet method. Therefore, a hybrid between 9-Matrix-based OSC construction methods is considered as a solution, away from the steel-box type combination, and a comparative study of the construction process between each construction method is being conducted. It was analyzed that the PC modular construction method shortened the construction period by 9% compared to the existing steel modular construction method. On the other hand, when comparing the construction period of the Gayang-dong demonstration complex calculated assuming that all modules are applied, it is estimated that there will be a 12% reduction in construction period compared to the steel modular method and a whopping 43% compared to the RC method.

• 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.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.740-741
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• 2015

the downscaled air temperature data over study region for the projected 2001 - 2099 period were then ensemble averaged, and the ensemble averages of 6 realizations were compared against the corresponding historical downscaled data for the 1961 - 2000 period in order to assess the impact of climate change on air temperature over study region by graphical, spatial and statistical methods. In order to evaluate the seasonal trends under future climate change conditions, the simulated annual, annual DJF (December-January-February), and annual JJA (June-July-August) mean air temperature for 5 watersheds during historical and future periods were evaluated. From the results, it is clear that there is a rising trend in the projected air temperature and future air temperature would be warmer by about 3 degrees Celsius toward the end of 21^st century if the ensemble projections of air temperature become true. Spatial comparison of 30-year average annual mean air temperature between historical period (1970 - 1999) and ensemble average of 6-realization shows that air temperature is warmer toward end of 21^st century compared to historical period.

• Journal of the Korean housing association
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• v.23 no.4
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• pp.49-57
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• 2012

This study was conducted to apply the modular construction method to Han-ok. The modular method, which is differentiated from the existing one, means a construction method that equipments, windows and interior materials are prefabricated as a six-sided object at a plant and then they are assembled at the least process on the spot. As for the theoretical observation, the theoretical basis to apply the modular method to the modular housing and Hanok was divided into environmental and economic aspect. In order to apply the modular method to Hanok, the unit scale and size were selected and the plane of unit module Hanok was developed. And a standard with regard to the unit combination and material lifting transportation method was set and planned. In addition, through the comparison the unit modular Hanok to the existing Hanok, the difference was analyzed and the strength was identified in terms fo design method, structure, construction method, period and cost. In final, the conclusion, with regard to the economic, technical application in future, was drawn through arranging the study contents. The unit modular Hanok to carry out the high-quality dwelling through construction period reduction, standardized construction materials and improved insulation performance can meet the demands for a paradigm of new construction technology.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.973-981
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• 2008

This document presents the JES(Joint Element Structure) method that has been adopted for the firs time in our country for the construction of the structure crossing under the railroad without open excavation. Front Jacking Method, Tubular Roof Construction Method, New Tubular Roof Method and Joint Element Structure Method are commonly used for the construction of structures crossing under the railroad. JES Method, frequently used in Japan recently, is a new method to construct the structures crossing under the railroad in a safe manner and in a relatively short period of time by utilizing the steel elements with the joints through which the load in the vertical angle to the axial direction is transferred to the next element. The elements are tied to each other through the joints to form the permanent walls of a Rahmen structure under the road without open excavation and without limitation to the length in a convenient way. Through the case study in the project of a Subway Box Culvert Improvement for the Gyeonguiseon Railroad in front of Yonsei University using the JES Method, the cost and period of construction in various types of soil is investigated compared to the Front Jacking Method. Furthermore, by analyzing the results of instrumentation measurements carried out throughout the construction, comparison between the actual displacement in the ground and the predicted displacement in the design is made to provide the considerations to be counted for the design. In conclusion, comparison in the field of economic feasibility, constructability and safety between the JES Method and Front Jacking Method, which is most frequently adopted in our country at present, is made to present the JES Method as a new alternative for the non-open excavation construction method for the structures crossing under the railway.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.647-652
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• 2011

Developments in the teaching of the National Diploma in Building students should be geared towards meeting the needs of the construction industry in South Africa. These needs are usually in the form of skills and knowledge required to resolve thorny issues encountered in practice. The lack of capacity in the construction industry needs to be addressed from the basis of ensuring that the education system caters for both mature entry and matriculation entry students. The paper looks at a comparison in performance between mature entry and matriculation (just finish High School) entry students focusing on the National Diploma in Building students at the University of Johannesburg. The paper will make a comparison between those students who work first before enrolling for their first year National Diploma in Building and those who are directly from high school. Cooperative education involves training and systematically developing students through the acquisition of the requisite skills, attitudes, values and knowledge required to adequately perform in their chosen careers. The paper describes the problems and experiences that have been encountered by both mature and matriculation entry students in their three years of study which affects their performance. The paper will then look at the value of prior experience in enabling students to finish their National Diploma in Building within a three year period. The paper closes with some recommendations for the future.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.6-7
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• 2019

In order to solve problems such as scattered dust, dust and chemicals harmful to the human body, workability in a confined space, quality performance, and the like generated during the field construction of the conventional waterproof sheet construction method, a waterproof sheet is used as a PC formwork, Which is produced by pouring concrete after PC installation, and evaluating the applicability of the development method in comparison with the construction method of polypropylene waterproof sheet construction method and the construction period, safety, quality, construction cost.

• Korean Journal of Construction Engineering and Management
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• v.19 no.4
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• pp.61-69
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• 2018

Research on additional indirect cost due to construction period extension in general contracts has continuously been active whereas the same for the subcontract operations has not been. In this research, we review previous research on evaluation methods for additional indirect costs which are widely being used on construction sites as well as previously proposed methods altogether, applying them to analyze model-cases for comparison. We acknowledge that this pattern for construction cost fluctuation over the construction period demonstrates an S-curve. This S-curve shaped indirect cost occurrence is then used to generate model-cases that are used throughout the research which models we applied previous evaluation methods on. Finally in pursuit of finding out some problems of evaluation methods, we came to derive a conclusion that the "Average Actual Cost Evaluation Method on Extended Duration," which, in turn, were proved to be valid for application on general contracts, was also valid for general application on subcontractor operations.