• Journal of the Korea Institute of Building Construction
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• v.20 no.6
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• pp.489-495
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• 2020

Whereas the control of the hydration heat in mass concrete has been important as the concrete structures enlarge, many conventional strategies show some limitations in their effectiveness and practicality. Therefore, In this study, as a solution of controling the heat of hydration of mass concrete, a method to reduce the heat of hydration by controlling the hardening of cement was examined. The reduction of the hydration heat by the developed Phosphate Inorganic Salt was basically verified in the insulated boxes filled with binder paste or concrete mixture. That is, the effects of the Phosphate Inorganic Salt on the hydration heat, flow or slump, and compressive strength were analyzed in binary and ternary blended cement which is generally used for low heat. As a result, the internal maximum temperature rise induced by the hydration heat was decreased by 9.5~10.6% and 10.1~11.7% for binder paste and concrete mixed with the Phosphate Inorganic Salt, respectively. Besides, the delay of the time corresponding to the peak temperature was apparently observed, which is beneficial to the emission of the internal hydration heat in real structures. The Phosphate Inorganic Salt that was developed and verified by a series of the aforementioned experiments showed better performance than the existing ones in terms of the control of the hydration heat and other performance. It can be used for the purpose of hydration heat of mass concrete in the future.

• Korean Journal of Construction Engineering and Management
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• v.5 no.6 s.22
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• pp.72-79
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• 2004

Critical Path-based project management has been applied to the construction projects with a goal of delivering projects within original costs and time estimates. These current project management methods, rarely make early finishes of construction Projects. In addition, current practices on time management seems not to take advantages of early finishes concepts due to student syndrome and Parkinson's Law, This research study applied the Theory of Constraints(n) in the estimation of construction project duration. While the TOC includes variety of management techniques, in this study, it refers to critical chain that has been used to develop the specific management technique in scheduling. The concept of critical chain is applied to this study to solve the problems associated with the current scheduling method. The efforts focus to solve the p개blems associated with current construction project scheduling methods by adopting both stochastic estimation technique and the concept of schedule buffer,

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.214-220
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• 2006

본 연구의 목적은 지역별 농업가뭄의 평가를 위하여 농업가뭄지표의 적용성을 분석하는 것이다. 가뭄발생 상황에 분석은 SPI, PDSI, SWSI, CMI, Decile 및 Percent of Normal에 대하여 농업가뭄에 대한 적용성을 검토하였다. 기존 가뭄지수에 대한 가뭄발생시기 및 심도에 대한 분석을 통하여 농업가뭄을 잘 나타낼 수 있는 농업용 저수지 저수율과 3개월 지체된 표준강수지수, 평년강우비율, 무강우일수 등 4가지를 농업가뭄지표로 선정하였으며, 이들 지수를 통하여 가뭄평가에 적용하였다. 농업가뭄 평가를 위하여 평시대비단계, 가뭄우려단계, 가뭄확산단계의 3단계로 구성된 기존의 가뭄단계를 가뭄진행상황의 판단을 위해 6단계로 세분하여 이에 대한 기준을 정립하였다. 농업용 저수지의 저수율에 따른 농업가뭄의 판단은 영농시기에 대한 농업용수의 공급에는 적당하지만, 겨울에서 봄으로 이어지는 영농준비시기 및 논에서의 영농이 끝난 후의 가을철 이후의 가뭄에 대해서는 대표적인 기준으로서는 미흡한 것으로 나타났다. 농업용 저수지의 저수율에 따른 농업가뭄의 표현은 저수율의 지연효과, 저수율과 가뭄심도의 일반화된 상관성을 수립하기 어려운 단점이 있으므로, 영농상황에 따른 시기별 저수율의 고려할 수 있도록 구성하고, 표준강수지수, 평년강우비율 및 무강우일수 등의 지수를 이용하여 보완하도록 하였다. 이를 통해 제시된 농업가뭄지표 및 가뭄단계에 의한 농업가뭄 평가 결과 농업가뭄 발생시기, 지속기간 및 심도에 대한 적용성이 우수한 것으로 분석되었다. 농업가뭄지표 및 농업가뭄단계는 농업가뭄 평가 및 웹기반 정보제공시스템의 구축을 통하여 농업가뭄 분석 및 판단에 이용하고 있다. 농업가뭄의 분석 및 평가를 위한 농업가뭄 평가시스템은 가뭄분석을 위한 자료의 수집 및 분석, 농업가뭄심도의 분류, 지역별 농업가뭄 상황의 도식화 등을 수행하도록 구성되어 있다. 농업가뭄 평가시스템을 통해 구축된 시기별, 지역별 분석결과는 DB를 통하여 관리되며, 홈페이지를 통하여 실시간 분석결과를 제공할 수 있도록 웹기반 정보제공시스템을 구축하였다. 이상과 같은 농업가뭄 평가 및 웹기반 정보제공시스템은 현재 한국농촌공사 농어촌연구원에서 시범운영중에 있으며 농업가뭄의 평가 및 대책수립을 위한 지원수단으로 효율적으로 활용될 수 있을 것으로 판단되었다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.606-609
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• 2003

The need of high-rise building is increased, because population is concentrated and the building site is limited in the city. Owing to this request buildings in downtown become more high rise. Therefore, we must develop the design, structure, high technology and materials. The core wall construction is one of the method of construction preferred because it cut down the cost and decrease the schedule. According to research in this study, we found that the selection process of core wall system form is focused on the schedule and cost. the construability is relatively failed to notice. As a result, the problem of construability is happened under the construction, it lead to delay the schedule and increase the cost. The purpose of this study is suggest to decision making process of core wall system form considered improving construction productivity.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.415-422
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• 1994

Recent new town construction project proouced large numbers of apartment houses using precast concrete (P. C.) panels. l'bst construction companies involved in this project put their management focus on to the individual control of P.C. panel producing plants and the job sites. Little attention was paid to the integrated management of the production. transportation. and im;tallation of P. C. panels. Numerous job site delays experienced in the new town project were largely based on the poor coordination between these three key disciplines of the P. C. apartment construction. This stlldy was initiated with an .intention to improve coordination between these disciplines. Activities of these disciplines were identified and related data were gathered. This was performed through the interv:iews with the personnel involved in P. C. constructlon and through the analy::;is of the related documents and publications. Based on this information. the authors are nolol developing a model IoIhich will provide a foundation for opt:iJnal.ly coorc.inated control of the proouction. transportation, and installation of P. C. panels for apartment construction. In this paper. the authors briefly present intermediate results of this study.

• Journal of Korea Water Resources Association
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• v.36 no.5
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• pp.715-724
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• 2003

It is true that SOC facilities, such as dams, need long life cycles since more time has to be invested for the phases of planning, examination, feasibility study, design, contract, construction, and maintenance. This longer life cycle is easily exposed to the risk. And thus, brings additional cost by the delayed project, convenient loss according to the additional run of use, and benefit lose of not to using the facilities. So, the purpose of this study is to try to find a solution to reduce these time consuming problems which could diminish the whole national competition. Hence, this study is to show efficient, systematical project performance and network model by using reciprocal analyses between the construction period and cost based on economical analysis of each phase of life cycles. In addition, on the basis of these outputs, the Fast Track Method is suggested as an alternative solution as a new Approach in Life Cycle's Analysis.

• Korean Journal of Construction Engineering and Management
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• v.19 no.2
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• pp.61-72
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• 2018

Conflicts in public construction projects lead to increase social costs as well as construction costs and schedule delay. Therefore, it is important to evaluate the conflict in construction project and find appropriate solutions based on previous cases. In this research, the conflict factors and criteria for evaluating conflict are derived and 30 cases are evaluated by 11 conflict experts. Using k-means clustering, the cases are clustered by three clusters. The cases were analyzed according to the characteristics of each cluster and labeled as 'NIMBY and harmful facility conflict cluster', 'environmental and pollution conflict cluster', and 'PIMFY and small conflicts'. In the future, when conflict occurs in the public construction projects, the conflict can be evaluated using this clustering and the characteristics of the conflicts can be found. As a result, it will be helpful to mitigate the conflict quickly and effectively by looking for previous cases that are suitable for resolving the conflict through appropriate clusters.

• Journal of the Korean housing association
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• v.28 no.1
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• pp.109-117
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• 2017

It becomes increasingly important to develop sustainable housing to protect environment. The certification system for long-life housing was made to use houses for more than one hundred years in 2014. The long-life housing should be able to meet new demands by change of the population structure; low birthrate, aging and increase of single households. Therefore, it is necessary to suggest a prototype of long-life housing for partial rent. The objective of this study is to suggest a prototype for dividing housing in the long-life validation complex, which has design consideration for dividable house. The construction costs of a prototype for dividing housing is evaluated by comparing with other prototype without regard to dividing housing. The results were as follows: (1) The prototype for diving housing should be added an entrance, bathroom, kitchen for tenant, and above all, maintenance fees for tenant have to be managed seperately from house owner. (2) The equipment system for dividing housing should be designed when planning the space of house. However, design for diving housing should be reflected the unit plan at a minimum on what will and will not happen.

• Journal of the Korean Society of Safety
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• v.26 no.2
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• pp.89-98
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• 2011

The traffic accidents at a construction site, which happen due to construction vehicles' frequent access to a construction site, its subsequent conflicts with ordinary vehicles and pedestrians, and inappropriate installation & management of traffic security facilities, have not many proportions in all traffic accidents, but obviously, the accident damage is quite serious when comparing the level of the fatal per one accident. This research conducted an analysis of traffic accident injury severity using Ordered Probit Model in relation to 241 traffic accident cases that occurred caused by construction sites among the traffic accidents that took place in Seoul and Gyeoggi-do region for two years from 2006 until 2007. As a result, the significant variables enough to explain traffic accident injury severity were analyzed to be the state of road surface, linear shape of an accident spot & whether the damaging car belongs to the vehicle for construction, and whether vehicles have access to a construction site at the time of an accident. Through this, this research found out some fact as follows: first, there need to be more aggressive management of the vehicles for construction and a year-round placement of the manpower who can control vehicular access to a construction site. Second, it is necessary to get drivers to recognize the fact that there exists a construction site on the construction section which is on the border of curved roads in advance to prevent a traffic accident, helping to reduce socioeconomic loss & costs incurred by a traffic accident.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.523-528
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• 2006

The management of construction materials is one of the important administration factor to perform construction projects. If it is not flexible to supply necessary materials to a workplace at a proper time, some problems such as a construction cost increase, an operation delay, a lowering of work efficiency and etc. could occur during the progress of work. Therefore, tracking the precise location of materials is important and necessary to input materials in the accurate place. Although Location sensing techniques comprise GPS, Active Badge, EasyLing and so forth, there are technical limitations to apply these techniques on construction site. Accordingly, in this paper, we propose the technically feasible method to automatically locate materials on site using recent RFID and wireless network technologies.