• Journal of the Korean Geosynthetics Society
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• v.22 no.3
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• pp.87-95
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• 2023

Recently, redevelopment of the original downtown area is underway, the necessity of construction in adjacent location is increasing. However, excavations in dense urban areas are prone to ground problems due to various causes, so it is necessary to use materials and methods that can minimize such problems. As a general earth retaining method, various methods such as diaphragm wall and CIP method are applied using cement. However, since a large amount of cement is used for the installation of earth retaining method, it is necessary to conduct research on the development of new cement substitute materials to significantly reduce greenhouse gas emissions. In this study, we utilized the hardening reaction of blast furnace slag powder, desulfurized gypsum and high calcium fly ash by alkali activation and applied it to the SCW method. As a result, it was analyzed that the compressive strength of solidified soil using development solidification material was 96.2 ~ 106.3% of OPC at 28 days of curing. In addition, the strength increment ratio was 2.06 for sandy soil and 2.41 for clayey soil, which was higher than 1.85 of OPC. It seems an advantageous in terms of long-term strength. In addition, from the environmental point of view, it was analyzed that there is no elution of heavy metals and that greenhouse gas emissions can be dramatically reduced. Therefore, if further studies are conducted, it can be applied to the SCW method.

• Journal of the Korean Geotechnical Society
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• v.32 no.3
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• pp.29-37
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• 2016

SSG (self-healing smart grouting) method, which is developed recently, has the characteristics such as an improvement of durability and waterproofing, prevention of leaching and pollution. In this study, we performed several tests such as gel-time measurement, uniaxial compression test, permeability test, fish poison test and chemical resistance test to compare the engineering properties of SSG with the other chemical grouting method (LW, SGR). As results of tests, the SSG method has low possibility of groundwater and ground pollution caused by leaching, furthermore, it has advantages like long/short term waterproofing, strength and durability. Therefore the SSG method can be applicable in the fields as an alternative of existing chemical grouting methods with problems.

• Journal of Korea Foundry Society
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• v.24 no.3
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• pp.153-158
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• 2004

본 연구에서는 기존 고압주조법의 해결과제인 고속충진 시 혼입되는 금형 cavity 내부의 유해 gas에 의한 gas porosity를 제어하기 위한 고속 사출 전 진공시스템 설계와 응고과정에서 발생되는 응고수축에 의한 shrinkage를 효과적으로 제어하기 위한 국부가압 스퀴즈의 조합시스템의 설계로 최적의 기계적 성질을 갖는 부품을 제조할 수 있는 공법을 개발하였다. 또한 개발된 신공법으로 자동차용 고내마모성 요구부품인 Reaction Shaft Support에 기존의 주철제를 대체하는 Al-15wt.%Si 과공정합금을 적용하여 시제품을 제조하였으며, 기존의 공법과 비교한 결과, 내부 porosity가 없는 미세하고 균일한 공정 및 초정 Si의 미세조직을 얻을 수 있었고, 기계적 특성평가에서도 매우 우수한 결과를 얻을 수 있었다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.221-221
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• 2004

플라스틱의 사출성형중 용용 수지에 가스를 주입하는 가스사출성형(Gas Assisted Injection Molding GAIM)에 의해 성형품을 만드는 생산방법은 약 30년 전부터 유럽지역을 중심으로 시작되었다 GAIN의 개발 배경은 발포성형을 대체하기 위한 공법으로 개발되었다. 발포성형은 싱크마크(sink mark) 제거, 치수안정성, 강도보강의 목적으로 사용하는 공법이지만, 가스기포가 표면으로 빠져나오고 표면에 가스 기포가 발생하여 외관부품에 부적당하며, 두께가 5-6mm이하의 성형품에는 적용할 수 없고, 성형시간이 긴 문제점을 가지고 있어 이러한 문제를 보강한 공법을 연구할 결과로 GAIM이 탄생하게 되었다.(중략)

• Journal of the Korea Institute of Building Construction
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• v.18 no.5
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• pp.419-427
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• 2018

The purpose of this study is to recycle steel slag generated from the iron producing process and to use steel slag as a construction material which is currently landfilled Steel slag is subjected to aging treatment due to the problem of expansion and collapse when it reacts with water. The Slag Atomizing Technology (SAT) method developed to solve these problems of expanding collapse of steel slag. In this study, experimental study on the emergency repair mortar using the reducing slag, electric arc furnace slag and silicon manganese slag manufactured by the SAT method is Reduced slag was shown an accelerated hydration when it was replaced with rapidly-setting cement, and the rate of substitution was equivalent to 15%. It is shown that the electric furnace oxide slag is equivalent to 100% of the natural aggregate, and it can be replaced by 15-30% when the silicon manganic slag is substituted for the electric furnace oxide slag. With the above formulation, it was possible to design the rapidly repair mortar for road use. These recycling slags can contribute on achieving sustainability of construction industry by reducing the use of cement and natural aggregates and by reducing the generation of carbon dioxide and recycling waste slag.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.6
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• pp.599-612
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• 2013

This study aims to investigate an economical efficiency of two excavation methods with respect to the room-and-pillar method for the underground space and conventional excavation method, i.e. 2-arch tunnelling method. For feasibility study, an excavation cost for both room-and-pillar method and 2-arch tunnelling method was estimated when the same space in operation was required. It was assumed that properties of reinforcements and rock were adopted from literatures. However, an excavation shape of the room-and-pillar method was assumed not to be the rectangular shape which is a general type in the room-and-pillar method but to be an arch shape in order to compare with the conventional excavation method (2-arch tunnelling) and to achieve the maximum bearing capacity of the structure during excavation. Consequently, the wider space in use or required and the better condition of rock we assumed, the more economical advantage we have in the room-and-pillar method than the 2-arch tunnelling method.

• Korean Journal of Construction Engineering and Management
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• v.9 no.6
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• pp.147-155
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• 2008

In the 1970s, increasing penetration of the housing co-housing policy, reconstruction be a great success to improve 1990‘s Old aged apartment's performance. However, in case of reconstruction, it causes the problem such as city environment destruction, resource waste, real-estate speculation etc. With the trend of sustainable construction and resource recycling, remodeling gets more attention than before. In case of country's remodeling, conventional method causes some problems such as delayed construction period and increased cost. Therefore, efforts that obtain economical efficiency are required to power remodeling through use of prefabrication method like PC technology that is useful for reduction effect of construction period, cost and site labor and excellent quality. This research indicates reduceing factor for facilitating prefabrication method and technology selecting framework through specific of Expanding Floor method and remodeling cases to increase the efficiency of remodeling, considers construction parties approaching plan for prefabrication as occasion that powers remodeling.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.654-658
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• 2006

To solve some problems that reveals in the exiting stickiness problem of the housetop, the housetop finishing impact layer can be displaced by the existing concrete block. By doing in this way, this need is rising that the excess cost should be reduced and the materials should be recycled in repairing. According to the above, this study is going to suggest the basic data on building and using of the dry process method by estimating and analyzing a overall determinate quantity through the experiment on the insulation performance among the capacity items on the outside insulation waterproof dry process suggested. In addition, choosing the building method according to the use, the peculiar property and the importance of the building can be possible by analyzing the defect causes happening in the rooftop insulation and waterproof, suggesting the better method and classifying the most proper choosing methods for the need of the building according to the importance of the main factors.

• Journal of the Korean Geosynthetics Society
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• v.4 no.1
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• pp.7-15
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• 2005

In recent years, the geotextile tubes filled with dredged material have been used in dike and breakwater construction for a number of projects around the world, and their use in this field is growing very fast. One of the most attractive advantages of geotextile tube technology is can be use the in-situ filling materials by hydraulic pumping, it can be also established lower costs and fast construction than other technology. Geotextiles form one of the two largest groups of geosynthetics and it is commonly made by two major types of polymer material(Polypropylene, Polyester). The objective of this paper is to examine several issues associated with drainage function and feasibility of geotextile tube structure such as filtering efficiency, dewatering efficiency, and filling process with polymer materials. Based on the laboratory filtering test and in-situ tests, polypropylene goetextile is more effective for drainage function of geotextile tube technology.

• Journal of the Korea Convergence Society
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• v.6 no.6
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• pp.163-169
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• 2015

This study was intended to suggest a new-concept construction method of permanent basement wall combined with earth retaining wall by using PHC piles to overcome the disadvantages of conventional CIP methods or the like which have been used just for earth retaining walls during field construction, and to determine its applicability. PHC piles are characterized by the reliable quality attributed to prefabrication (shop fabrication) as well as superior concrete strength and prestressing steel strength to that of CIP in the aspect of materials, and also higher bending moment than that of CIP in the aspect of structure.