• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.6
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• pp.95-102
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• 2007

Recently, an improved capacity for RC bridges is required by their deterioration or necessary to carry traffic increase. Strengthening is known as a better way to improve capacity of bridges than reconstructing in terms of economy. The surface bonded method, which is normally used with FRP material, has some advantages related to conveninent application and time-save among other strengthening methods. FRP material is light and has high tensile strength compared to steel. Therefore, this paper presents how structural capacity strengthed with CFRP sheet and Glass fiber-Steel Plate (GSP) is improved.

• Korean Journal of Construction Engineering and Management
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• v.12 no.5
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• pp.71-80
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• 2011

Flying net should be installed on every 3 or 4 construction floor from 8m above ground according to the rule. In the apartment housing construction, flying net installation work has been recognized the most dangerous work among the whole works because a small mistake of labors might make their death accident. Sub-contractors specialized in flying net have been developing various flying net types. However, most works of installing flying net as working with the developed system are performed outside the apartment housing, so that the risk of fall in works of installing supports and unfolding net is still high. Furthermore, as using the previously developed flying net labors might bump into the frame or the wire rope for supporting so that it makes secondary accidents. The objective of this research is to produce the proto-type of anti-collision flying net system based on the result of problem analysis on the installation and detachment process and suggest the improved anti-collision flying net system, which is able to improve safety and field applicability by conducting field experiment and analyzing performance.

• Korean Journal of Construction Engineering and Management
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• v.24 no.5
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• pp.12-21
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• 2023

Green remodeling proposed in the Korean New Deal is a project to build or remodel eco-friendly and energy-efficient buildings using renewable energy facilities and high-performance insulation for public buildings. The government intends to achieve the carbon emission reduction target by conducting green remodeling. Major overseas cities that conduct green remodeling are actively promoting technology support and promotion along with energy performance evaluation according to building characteristics, subsidies for private revitalization, and tax benefits. With this background, the analysis of the current status and problems of the green remodeling project was performed and the Activation factors of Green Remodeling were derived from survey results. This study suggested strategic measures such as a participation of civil society, promotion, and priority selection of administration and policy measures such as a leading role of the public sector, expanding support for the socially underprivileged, and financial support and tax benefits. And this study results are expected to be utilized as basic data to promote the green remodeling project.

• Explosives and Blasting
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• v.35 no.1
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• pp.43-52
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• 2017

Mountain and hill areas occupy by more than 70% in South Korea and Rock drilling should be applied in order to reduce noisy & vibration from massive civil engineering business such as road expansion, high-way construction, subway construction and construction of site renovation such as a newly-built & re-development of apartment, newly-built of high-rising building in downtown area. As Blasting noise & vibration such as vibration, noise, fly rock etc caused by blasting operation from large small scale construction occurs, neighboring residents who demand the compensation file a civil complaint so that the business reach a deadlock. As the excavation method for these areas, There are blasting of micro-vibration, mechanical excavation method(Rock splitter, Breaker etc), similar blasting method(plasma, gel fragmentation etc) to date. In this study, we are trying to find the feature & performance which get improved economic feasibility & construct ability through improving sympathetic detonation of New KINECKER-I used in blasting of micro-vibration & formulation and would provide convenience for use by introducing standard blasting pattern & construction method. Also, checked and confirmed all the blasting with connecting cap has been cleary detonated.

• Land and Housing Review
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• v.7 no.4
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• pp.323-328
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• 2016

There are small box opening for inserting of electric lamp box in the slab of apartment. Around this box opening, we normally use the detailing of WWF or plastic ring strengthening to protect cracks induced by shrinkage. The shrinkage amount of slab box around was measured and analysed in order to consider validity of these strengthening methods and to find out economical alternative. Alternative of strengthening methods are normally used strengthening methods in construction companies, which are WWF strengthening, plastic ring strengthening and no strengthening methods. The shrinkage amount was measured using contact guage at the spot of tip attached around the box on slab of small area unit apartment which have small exclusive area below $59m^2$. Measured data shows that there are no big differences between all the 3 strengthening methods and Measure data range is $-264{\mu}{\varepsilon}{\sim}+216{\mu}{\varepsilon}$. Measured shrinkage is on trend slightly increase till 3~5weeks after removal of forms and then decrease. But amount of shrinkage are very low for all the slabs and there are no probabilities of concrete crack by shrinkage.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.2
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• pp.9-20
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• 2014

Steel intermediate moment frames (IMFs) have been generally used as seismic load resisting systems (SLRSs) of a building to provide resistances against strong ground shaking. However, most of low and mid-rise steel buildings in Korea were constructed during pre-seismic code era or before the introduction of well-organized current seismic codes. It has been recognized that the seismic performance of these steel IMFs is still questionable. In order to respond to such a question, this study quantitatively investigates the seismic capacities of steel IMFs. Prototype models are built according to the number of stories, the levels of elastic seismic design base shear and the ductilities of structural components. Also, the other prototype models employing hysteretic energy dissipating devices (HEDDs) are considered. The collapse mechanism and the seismic performance of the prototype models are then described based on the results obtained from nonlinear-static and incremental-dynamic analyses. The seismic performance of the prototype models is assessed from collapse margin ratio (CMR) and collapse probability. From the assessment, the prototype model representing new steel IMFs has enough seismic capacities while, the prototype models representing existing steel IMFs provide higher collapse probabilities. From the analytic results of the prototype models retrofitted with HEDDs, the HEDDs enhance the seismic performance and collapse capacity of the existing steel IMFs. This is due to the energy dissipating capacity of the HEDDs and the redistribution of plastic hinges.

• Korean Journal of Construction Engineering and Management
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• v.15 no.6
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• pp.35-43
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• 2014

Ministry of Land, Infrastructure and Transport (MOLIT) promote long-life housing to reduce social costs generated by poorly considered rebuilding and extend the life-span of housing. Long-life housing has advantages of durability, floor plan variability, efficient maintenance and ease of remodeling because it is a beam-column structure building. However, long-life housing requires somewhat higher initial construction cost than wall type apartments. It makes increase of long-life housing more difficult. In this study, we compare between wall-type apartment and beam-column structure apartment from Life-Cycle Cost's viewpoint. As a result of the study, long-life housing incurs 18% higher initial cost than wall type apartment, but is 7% more economical than wall type apartment in terms of Life Cycle Cost. Therefore, it is shown that long-life housing could be a beneficial alternative to traditional wall type apartments.

• Korean Journal of Construction Engineering and Management
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• v.19 no.4
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• pp.34-42
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• 2018

Apartment is a typical type of housing preferred by the majority of people. However, and defect disputes occur because various defects such as cracks, subsidence, breakage, water leakage, dew condensation and dropout are confirmed with numerous structures and finishing materials. From this point of view, this paper analyzes defect frequency and costs of each warranty period by work types, and estimates defect risks by using defect dispute cases. It examined about 5,337 defect items for 32 apartment over ten years old. In this paper, there are 10 types of work types and the warranty liability period is divided into 6 categories. Based on these categories, defect frequency and costs are investigated, and finally defect risk of the warranty liability period by work types confirmed. As a result of this analysis, it was found that defect risk in RC and finishing work is very high. Especially the RC work revealed that there is a high risk of trying from the third year onwards and it was found that the defect risk up to the second year is high in the finishing work. Due to aging of RC structure, the defect risk gradually increases, and finishing work initially cause defect disputes because of the housing environment.

• Journal of Korean Society of Disaster and Security
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• v.15 no.3
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• pp.57-66
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• 2022

According to the official letter of the Ministry of Employment and Labor (recent guidance on the status of deaths in the construction industry and thorough safety management, April 4, 2022), 17 deaths occurred in construction works worth more than 5 billion won until March 31, 2022. In terms of the size of the construction, 7 cases of 5 billion won to 12 billion won, 5 cases of 12 billion won to 80 billion won, and 5 cases of more than 80 billion won occurred. The causes of death accidents were found to be nine cases (50%), five cases (28%), two cases of collapse (11%), one case of entrapment (5%), and one case of drowning (5%). Safety facilities need to be strengthened to reduce deaths caused by falling, which accounts for most of the deaths, and if fall prevention nets, openings, and safety rails are completely installed, most falling accidents can be prevented. Therefore, this paper intends to present cases of development and use of patent technology through improvement of safety facilities in order to prevent accidents corresponding to the fall of new urban living housing sites, which are small apartment houses.

• Journal of the Korea Institute of Building Construction
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• v.22 no.4
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• pp.347-358
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• 2022

In order to satisfy the extraction and use of information such as estimates and processes required in the design and construction stages of BIM, which is an expectation of overall construction operation for the design and construction stage of domestic buildings, it is insufficient to supply and apply mobile technologies or terminals. In this paper, standardization of BIM-based processes from the design stage to the construction stage is proposed as an efficient construction system method through mobile-based simulation and test-bed case analysis review. The current status and potential of BIM application were identified through theoretical review of BIM and case studies at home and abroad. In addition, the overall flow of the project and the direction of effective process construction were investigated through each process by 3D, 4D, and 5D execution stage and the role of each collaborator. 4D building process BIM simulation system using mobile was implemented by applying a visualization engine that simulates process information, object information connection module, and related object information. Therefore, it was possible to minimize the possibility of re-construction of the BIM design and construction process model through the visualization of 2D drawings based on the 3D model of the building and the review of errors and interferences in the drawings. In addition, in the implementation of simulation for each process of the construction process through mobile devices, it was possible to support construction progress and process management according to the optimal option selected by the user.