• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.85-86
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• 2012

This application plan is hasty prepared with the actual condition in which the majority is reclaimed by the waste with the marine and the polysilicon sludge, that is the main raw material of the solar pannel support, does. In this research, by using OPC and Fly ash, the applicability as the blending material of the polysilicon sludge was analyze and it tried to contribute to the waste reduction afterward. The replacement ratio of the sludge was set to 5. 10, 15, 20(%) with the experiment based on the based test result and the air flow rate, liquidity, flexural strength, and compressive strength was measured. The liquidity was reduced in spite of as the replacement ratio of the sludge increased and the air flow rate increased.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.25-26
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• 2018

In this study, the device was developed for evaluating the effect of pressure on chloride ion penetration of concrete. And chloride-ion penetration depth and water soluble chloride contents was evaluated concrete using ordinary portland cement and blast-furnace slag cement using developed device. As a result, chloride ion penetration of concrete was promoted according to the action of pressure and the exposure period. and the incorporation of blast-furnace slag was effective for chloride attack resistibility under pressure.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.330-331
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• 2018

It's prohibited to take sand from southeastern EEZ(Exclusive Economic Zone) from January 2017 in korea. So, the supply of sea sand has been decreased and costs of sea sand are rising as a result in the southeast region. This paper deal with appropriateness of the taking sea sand, circumstance and fisheries damages by extraction of EEZ sand and proposed control measures for ensuring quality of sea sand and consider fishermen support plan for ensuring a stable supply of sand in southeast region of korea.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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• pp.50-51
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• 2015

In marine and coastal environments, penetration of chloride ions is one of the main mechanisms causing concrete reinforcement corrosion. Currently, most of experimental investigations about submerged penetration of chloride ions are started after the four weeks standard curing of concrete. The further hydration of cement and reduction of chloride diffusivity during submerged penetration period are ignored. To overcome this weak point, this paper presents a numerical procedure to analyze simultaneously cement hydration reaction and chloride ion penetration process. First, using a cement hydration model, degree of hydration and phase volume fractions of hardening concrete are determined. Second, the dependences of chloride diffusivity and chloride binding capacity on age of concrete are clarified. Third, chloride profiles in hardening concrete are calculated. The proposed numerical procedure is verified by using chloride penetration test results of concrete with different mixing proportions.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.90-91
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• 2017

Concrete can be used semi-permanently unless the steel is corroded. However, the concrete exposed to the marine environment is exposed to sea breeze, so chloride ions penetrate into the concrete and the steel is corroded accordingly. In order to solve these problems, there is a method of increasing the covering depth of the concrete and an application of the epoxy paint to the steel. In this study, the hydrotalcite type corrosion inhibitor was mixed with the concrete and the compressive strength, chloride diffusion coefficient and the corrosion properties of the steel were examined.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.57-58
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• 2022

Reinforced concrete (RC) structures play a significant role in the construction industries. An embeddable solid-state reference electrode (ESSRE) was used to evaluate the corrosion status of steel rebar in the concrete of various cover thicknesses that exposed to the maritime environment (3.5 % NaCl) in this study. From the open circuit potential measurement (OCP), the passive state, the corrosion uncertainty, and the 90% probability of corrosion state of the steel rebars in the concrete were monitored by ESSRE. From the electrochemical impedance spectroscopy (EIS) method, severe corrosion was observed at the exposure period of 1510, 1847, 2350, and 3020 h for C10, C15, C20, and C30 concrete, respectively. The results confirm that the ESSRE can be useful to identify the corrosion occurrence and severe corrosion of steel rebar embedded in different cover depth concrete structures.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.109-110
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• 2021

An attempt has been made on a constructive approach to evaluate the performance of snail shell ash (SSA) for its corrosion performance under marine environments. Corrosion performance of steel rebar in chloride contaminated SSA with (0% to 50%) replacement levels of cement extract medium was examined through electrochemical and weight loss techniques. Initially, snail shell powder (SSP) is made by pulverizing and subsequently SSA is by thermal decomposition methods. A critical level of 20 % SSA improved both corrosion resistance properties of cement extracts. SSA is a suitable replacement material for natural limestone in cement productions.

• 대한조선학회논문집
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• 제43권1호
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• pp.103-118
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• 2006

At the initial design stage, the generation process of the production material information of a building block and the simulation process of the block erection, which are required to perform the production planning and scheduling, have been manually performed using 2D drawings, based on the data of parent ships, and subjective intuition from past experience. To make these processes automatic, the accurate generation method of the production material information and the convenient simulation method of the block erection based on the initial hull structural model(3D CAD model), were developed in this study. Here, the initial hull' structural model was generated from the initial hull structural CAD system early developed by us. To evaluate the developed methods. these methods were applied to corresponding processes of a deadweight 300,OOOton VLCC. As a result. it was shown that the production material information of a building block can be accurately generated and the block erection can be conveniently simulated in the initial design stage.

• Geomechanics and Engineering
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• 제28권6호
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• pp.585-598
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• 2022

The monopile-friction wheel hybrid foundation is an innovative solution for offshore structures which are mainly subjected to large lateral eccentric load induced by winds, waves, and currents during their service life. This paper presents an extensive numerical analysis to investigate the lateral load and moment bearing performances of hybrid foundation, considering various potential influencing factors in sand-overlaying-clay soil deposits, with the complex lateral loads being simplified into a resultant lateral load acting at a certain height above the mudline. Finite element models are generated and validated against experimental data where very good agreements are obtained. The failure mechanisms of hybrid foundations under lateral loading are illustrated to demonstrate the effect of the friction wheel in the hybrid system. Parametric study shows that the load bearing performances of the hybrid foundation is significantly dependent of wheel diameter, pile embedment depth, internal friction angle of sand, loading eccentricity (distance from the load application point to the ground level), and the thickness of upper sandy layer. Simplified empirical formulae is proposed based on the numerical results to predict the corresponding lateral load and moment bearing capacities of the hybrid foundation for design application.

• 해양환경안전학회지
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• 제29권7호
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• pp.794-801
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• 2023

전 세계 해양의 대부분을 차지하는 공해는 해양바이오산업 성장에 필수적인 귀중한 해양 자원을 보유하고 있다. 이러한 글로벌 노력의 최전선에는 한국의 공해 자원 확보 및 기초효능(기초물질) 탐사사업이 있다. 이 연구는 대중의 인식을 측정하고 프로젝트의 이점을 정량화하여 향후 정책 결정에 대한 통찰력을 제공하고자 했다. 결과에 따르면, 연평균 지불의사액(WTP)은 3,778.8원으로, 전체 국민으로 확장하면 약 815.4억 원에 해당하는 것으로 나타났다. 본 연구의 의미는 두 가지이다. WTP를 기반으로 공해상 해양생명자원 확보의 경제적 가치는 연간 약 815억 원에 달할 정도로 상당하다. 이는 투자에 대한 WTP를 고려할 때 향후 정책 수립을 위한 중요한 참고 자료로 제공 가능하다. 해양생물자원에 대한 관심이 높아지고 있는 반면, 대중의 인식은 상대적으로 낮은 편이다. 그러나 본 사업은 해양바이오산업에 필수적인 데이터베이스를 구축하고 국제 해양생물자원을 확보하는데 있어서 중요한 역할을 하고 있다. 대중의 관심과 지속적인 지원은 이 사업 뿐만 아니라 향후 정책 구현에도 매우 중요하다. 대중의 인식을 높이는 전략은 필수적이며, 연구 결과는 향후 정책 결정에 귀중한 의견을 제공한다.