• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.241-242
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• 2019

This technology is a water leak repair technology using composite materials of concrete structures that block leakage of structures by injecting rapid microcement into the face of underground concrete to block water and injecting flexible glycidylacrylate. Rapid micro cement system repair materials are mixed with fine fibers to improve the flexural sensitivity of the material and to form a layer that blocks stabilized water at the back of the structure by allowing rapid and tight spatial filling during injection with high cohesion The glycidylacrylate repair material can control the expansion rate, and the external stress also has the characteristic that the form of the material is not destroyed or separated, which can also be applied to vibrating induced structures that produce repetitive fatigue loads, and has an effective durability in saline, alkali, acid (chloric acid, sulfuric acid, nitric acid).

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.100-101
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• 2020

In this study, the temperature history and compressive strength of the concretes according to the type of cement were measured and analyzed in comparison as part of the experiment on the material mixing side to reduce the hydration heat crack of the mat foundation constructed with mass concrete. As a result, the peak temperature and maximum temperature reach time of concrete using high rapid cement were shown to be similar to that of semi rapid cement. In particular, in compressive strength after three days, semi rapid cement was measured higher than that of concrete using high rapid cement. Therefore, if semi rapid cement is used in accordance with the site conditions, it is deemed possible to shorten the air due to reduction of temperature cracks and improvement of initial strength.

• Journal of the Korea Institute of Building Construction
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• v.16 no.3
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• pp.279-288
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• 2016

The fundamental performance of any construction material should cover at least two phases: safety and serviceability. Safety commonly represents adequate strength, while serviceability encompasses the control of cracking and deflections at service loads. With respect to rapid hydraulic binders as a construction material, the above two phases should also be considered. Recent research on rapid cooling ladle furnace slag (RC-LFS) has drawn much attention, particularly given that it shows remarkable rapid hydraulic ability to pulverize to a fineness of $6,300cm^2/g$. This industrial byproduct could contribute to developing the sustainability of the rapidly hardening cementitious material system. This paper aims to expand upon the applicability of an RC-LFS-based binder that is composed of two parts. It also seeks to illustrate the engineering performance of an RC-LFS-based hybrid fiber-reinforced composite and to increase the strength of the RC-LFS-based composite. Each step of this experiment followed ASTM standards. The engineering performance, in both fresh state and hardening state, was tested and discussed in this paper. According to the experimental results for fresh concrete, the air content increased following the addition of polypropylene fiber. For hardened concrete, the toughness and strength improved following the addition of a hybrid fiber. The hybrid fiber mixture, which contains 0.75% of steel fiber and 0.25% of polypropylene fiber, shows even better engineering performance than other mixtures.

• Korean Journal of Computational Design and Engineering
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• v.9 no.1
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• pp.77-91
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• 2004

Integrating computer-aided design with computer-aided fabrication and construction will fundamentally redefine the relationship between design and construction. Rapid prototyping(RP) is evaluated as one of the integration method available but it has been regarded as very expensive and complex design evaluation tool and is only suitable for large mechanical design shops in automobile and aerospace industry. However current status of rapid prototyping is changing since the new generation of RP equipment, less expensive and more user-friendlier, now can be installed and use in design firms. Simultaneously increasing use of 3D CAAD software is also helping to use rapid prototyping widely. It is crucial to acknowledge rapid prototyping technologies are not only for avant-garde architect such as Frank O. Gehry but ordinary 90% architects, who can have benefit from fast and cost-effective technology. With its fast development and adaptation in architectural industry, it is quite necessary to include rapid prototyping education in regular CAAD courses either undergraduate or graduate level.

• Journal of the Korean Society for Advanced Composite Structures
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• v.6 no.3
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• pp.14-19
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• 2015

In this study we developed an integrated precast concrete decks for a rapid construction. The structural performance in the integrated precast bridge decks is evaluated by real-scale test bed and detailed finite element analyses. The numerical analysis results were compared with the experimental data from a real-scaled single-span precast/prestressed concrete bridge decks under truck loading. Parametric studies are focused on the various effects of external loads on the structural behavior for different locations and measuring points on the precast bridge decks. The assessment in this study indicates that the integrated precast bridge decks show an excellent structural performance as expected.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.214-219
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• 2008

Recently, railway has been pointed to the efficiency of transportation, rapid transit, and comfortable train ride. In the case of domestic situation, both rapid transit railway and existing railway have been operated in higher speed and the construction of railway near the city building has been increased as well. Because of the rapid transit system and heavy railway, the noise and vibration of railway has been increased so that the strong standards in terms of environmental matter should be required. Therefore, the solution to avoid environmental matters becomes one of the most important factor in constructing railway. In this study, floating slab system which is one of the solution to avoid noise and vibration in railway has been introduced, and the foreign technology and the trend of this business has been investigated. In addition, the method of conceptual design and construction of floating slab system according to the isolator has been introduced.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.341-344
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• 2005

Recently, the application of Rapid Setting Cement has been gradually increased as an important construction. However, Rapid Setting Cement shows brittle failure. Therefore, in this study, tests are carried out using Rapid Setting Cement containing fiber in order to improve such a poor property. silica-cement ratio are varied. According to experimental results, Fiber reinforced Rapid -Setting Cement showed the high ductility and strain capacity regardless of silica-cement ratio. With 0.5 silica-cement ratio, a bending strength is the highest.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1143-1148
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• 2005

Recently, the application of construction IT (Information Technology) is recognized as an essential tool for the effective construction management and construction CALS. And the large construction projects are already using PMIS tool, and the application of construction IT tool will be accelerated by rapid popularization of computerized construction management system. This study defines a concept of construction IT and suggests an improved method to apply construction IT tool for construction supervision system.

• Journal of the Korean GEO-environmental Society
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• v.24 no.5
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• pp.21-28
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• 2023

In this paper, an experimental study was conducted to present the properties of rapid hardening composite mat, and a numerical analysis was carried out to analyze the slope protection effect of the mats based on ground conditions, rainfall, slope gradient and soil height. As a result, the application of rapid hardening composite mat increased the slope safety factor in all conditions, and the increase rate of safety factor showed an average of 40% increase both in dry and rainy seasons. Through these research findings, the protective effect of the rapid hardening composite mat on sloping surfaces has been proven, and it is suggested that the rapid hardening composite mat is suitable for application in areas where slope failure or collapse is expected.

• Korean Journal of Construction Engineering and Management
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• v.7 no.2 s.30
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• pp.109-117
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• 2006

Recent rapid changes such as construction market reduction, lowest bidding system of construction cost, five days per week system, and post-construction sale system are inevitably accelerating the competitiveness between construction companies. Those rapid changes of construction environment require construction companies, which are main participants of construction industry, to adapt to the changes and more to lead new construction environment. However, there are many construction uncertainties which could delay construction completion. Without the proper identification of construction uncertainties, structured strategy establishment and management of construction schedule, the competitive advantages of construction duration could not be made. Thus this paper limited the research boundary to construction duration competitiveness instead of general strategy establishment. Recognizing the importance of proper calculation of construction duration, requirements of construction duration reduction and limited researches related to construction schedule strategy, we established the 25 strategies for construction duration competitivenss by internal and external construction environment analysis and SWOT analysis, and then elicited the first considerations to accomplish the strategies through concensus of all the staffs by questionnaire, brainstroming and face-to-face interviews.