• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.91-95
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• 2003

There is a problem to be solved for improvement of durability and safety supervision. When you do the waterproofing and anticorrosive work of main concrete from the design stage, the material and method of construction need to be correctly applied to appropriate circumstance conditions. Epoxy have mostly been used for concrete water tank structure. Lately, lots of subjects on adaption of polyurea resin waterproofing and anticorrosive are under discussion. Then, we attempt to approach by evaluating and comparing every capabilities with another waterproofs in this study. Performance evaluation items include the adherence performance. the imprint of seal performance, temperature dependence performance. promotion westernizing ability, inner chemical performance. drinking water eruptive performance. Through the experiment analysis, we found that the polyurea resin waterproofing membrane is dominantly superior to other waterproofs. According to this study, we suggest the polyurea resin waterproofing membrane as a new waterproofing material for concrete structure.

• Advances in concrete construction
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• 제4권3호
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• pp.207-220
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• 2016

The objective of this study was to evaluate the influence of recycled materials, namely, shredded scrap tire (SST), reclaimed asphalt pavement (RAP) and class C fly ash (CFA) on compressive and tensile strength of concrete. Either SST or RAP was used as an aggregate replacement and class C fly ash (CFA) as Portland cement replacement for making concrete. A total of two types of SST and RAP, namely, chips and screenings were used for replacing coarse and fine aggregates, respectively. A total of 26 concrete mixes containing different replacement level of SST or RAP and CFA were designed. Using the mix designs, cylindrical specimens of concrete were prepared, cured in water tank, and tested for unconfined compressive strength (UCS) and indirect tensile strength (IDT) after 28 days. Experimental results showed aggregate substitution with SST decreased both UCS and IDT of concrete. On the contrary, replacement of aggregate with RAP improved UCS values. Specimens containing RAP chips resulted in concrete with higher IDT values as compared to corresponding specimens containing RAP screenings. Addition of 40% CFA was found to improve UCS values and degrade IDT values of SST containing specimens. Statistical analysis showed that IDT of SST and RAP can be estimated as approximately 13% and 12% of UCS, respectively.

• Structural Engineering and Mechanics
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• 제51권4호
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• pp.663-683
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• 2014

In order to study the dynamic failure mechanism and aseismic measure for high concrete gravity dam under earthquake, the comparative models experiment on the shaking table was conducted to investigate the dynamic damage response of concrete gravity dam with and without the presence of reinforcement and evaluate the effectiveness of the strengthening measure. A new model concrete was proposed and applied for maintaining similitude with the prototype. A kind of extra fine wires as a substitute for rebar was embedded in four-points bending specimens of the model concrete to make of reinforced model concrete. The simulation of reinforcement concrete of the weak zones of high dam by the reinforced model concrete meets the similitude requirements. A tank filled with water is mounted at the upstream of the dam models to simulate the reservoir. The Peak Ground Acceleration (PGA) that induces the first tensile crack at the head of dam is applied as the basic index for estimating the overload capacity of high concrete dams. For the two model dams with and without strengthening tested, vulnerable parts of them are the necks near the crests. The results also indicate that the reinforcement is beneficial for improving the seismic-resistant capacity of the gravity dam.

• 한국양식학회지
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• 제4권1호
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• pp.1-12
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• 1991

1987년 4월 10일부터 10월 16일까지 $4,000\;\ell$ 콘크리트 탱크 및 $270\;\ell$ 유리 수조를 이용한 폐쇄순환여과사육장치내에서 크기에 따른 일일성장률과 사료계수를 측정하기 위하여 다음과 같은 실험을 실시하였다. 실험에 사용된 어체의 크기는 평균체중 7 g 에서 1,000 g 되는 일본계통 틸라피아 Oreoohromis niloticus 였다. 매실험마다 최초방양 무게는 콘크리트 탱크에서는 200 kg (수량의 $5{\%}$), 유리 수조에서는 $10{\~}20$ kg (수량의 $3.7\%{\~}7.4\%$)으로 조절하였다. 매실험사육기간은 14일 전후였다. 수온은 $26^{\circ}C$ 내외로 유지시키도록 했는데, 약간의 변화는 피할 수 없었다. 용존산소는 약 $3\;mg/\ell$ 이내로 조절하였으며, 암모니아는 유리 수조에서 일시 $18\;mg/\ell$ 까지 상승한 적도 있으나, 일반적으로 $4\;mg/\ell$ 이었으며, 콘크리트 탱크에서는 약 $1\;mg/\ell$ 로 유지되었다. 어체중 약 10 g에서의 사료계수는 0.9, 일일성장률은 $3.5{\%}$ 였으며, 어체중 약 800 g 때의 콘크리트 탱크에서의 일일성장률은 $0.8{\%}$, 유리 수조에서의 일일성장률은 약 $0.5{\%}$이었다. 실험어는 대두정을 주성분으로 한 $32{\%}$ 조단백질을 함유한 사료를 공급하였다. 이번 실험의 결과에 따라서 식용어로 될 수 있는 틸라피아를 생산하는데 소요되는 기간은 계산상 다음과 같이 나타났다 즉, 콘크리트 탱크($7m^{2}$)에서는 50 g 되는 치어를 방양하여 1,000 g 까지 기르는데 223일 걸리며, 유리 수조에서는 10 g되는 치어를 방양 800 g 까지 기르는데 302일이 걸린다.

• 공업화학
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• 제22권3호
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• pp.332-335
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• 2011

친환경 재료에 대한 관심이 급증함에 따라 재료의 구조적 기능성 및 투수성을 동시에 갖는 다공성 콘크리트의 활용이 증가되고 있다. 본 연구에서는 다공성 콘크리트에 제올라이트를 혼합하여 다양한 활용도를 갖는 다기능형 옥석 제품의 수질정화 능력을 평가하여 친환경제품으로서의 적합성을 검토하였다. 흐름이 없는 시험용 수조에서 시간에 따른 오염도 제거율은 T-N (70.6%), T-P (67.0%), BOD (57.7%), TOC (50.6%) 순으로 우수한 수질정화 특성을 보였다. 또한 유입 및 유출이 가능한 비점오염원에서 시간에 따른 유출부에서의 수질오염도 및 중금속 농도의 제거율은 Zn (99.9%), Pb (90.0%), BOD (69.2%), COD (33.5%) 순으로 흐름이 없는 경우에서의 오염도 제거율보다 수질정화 특성이 우수한 것으로 나타났다. 따라서 다공성 콘크리트 시설물을 실제 하천 등에 시공했을 시에 우수한 오염도 제거율을 바탕으로 친환경제품으로 적합함을 확인할 수 있었다.

• 한국환경과학회지
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• 제18권12호
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• pp.1339-1347
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• 2009

This study tried to investigate and analyze the actual state such as the regional, classified, and material characteristics of the water quality in order to research the several factors by which the filtrated water of the total 250 cases can be polluted in the water tank. The 215 points (86%) clean the water tanks twice a year regularly and J-city has done the best job of cleaning the water tanks. The fifty points (20%) of the total 250 investigation points examine the water quality of the water tanks every year, however, the 175 investigation points (70%) do not execute the inspection of water quality. In the case of the regional characteristics in the water quality, the 23 points (46%) in H-county, the 17 points (34%) in S-county, and the 16 points (32%) in G-city are incongruent in the standard, and the incongruity ratio of the water quality in J-city is the lowest. The result of the classified incongruity shows that total coliforms were found at the 61 investigation points, mesophilic bacteria were found at the 27 points, and turbidity was found at the 12 points. In the case of the material incongruity, concrete was found at the 63 investigation points as the most distinguished factor, and FRP (fiberglass reinforced plastic) at the 23 points, SMC (sheet molding compound) at the 12 points, and stainless steel was found at the 2 points.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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• pp.77-81
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• 2010

This study deals with the analysis of color-difference and physical property of anti-corrosion coatings using at inside of concrete tank for drinking water. Because anti-corrosion coatings are effected by chemical attack, color and physical property are changed. So in this study when epoxy resin coatings of 3 types were received chemical attack by Cl- and NaOH, we present the co-relationship between color-difference and bond strength. For this study, we used the colorimetry, which can measure the degree of color difference on surface of materials. As the results, in case of Cl-, color change is appeared, bond strength also is decreased. From this experiment, we could know that color change due to chemical aging has the deep relationship with physical performance(bond strength) materials. further researches are needed.

• 한국소음진동공학회논문집
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• 제15권7호
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• pp.806-812
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• 2005

This paper adresses the shaking table tests with 1/100 scaled model followed similitude law for OOdam main designing section to understand nonlinear behavior characteristics of concrete dam body by ground motion. As earthquake wave, Hachinohe and El Centre waves were used and acceleration and displacements are measured to analyze behaviors of dam body. For maximum ground acceleration range $(0.3\~0.9 g)$, the results showed linear behavior regardless of maximum 9round acceleration and secured safety of structure. To analyze the behavior of dam after tension cracking, 3 cm-notch was placed at the critical section of over-flowing section. As results of applying Hachinohe wave(0.8 g), Even though tension cracks were formed at over-flowing section by Hachinohe wave(0.8 g), it showed that the dam is stable for supporting upper stream Part of water tank of dam.

• Structural Engineering and Mechanics
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• 제10권6호
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• pp.533-543
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• 2000

To prevent major cracking and failure during earthquakes, it is important to design reinforced concrete liquid storage structures, such as water and fuel storage tanks, properly for the hydrodynamic pressure loads caused by seismic excitations. There is a discussion in recent Codes that most of the base shear applied to liquid containment structures is resisted by inplane membrane shear rather than by transverse flexural shear. The purpose of this paper is to underline the importance of the membrane force system in carrying the base shear produced by hydrodynamic pressures in both rectangular and cylindrical tank structures. Only rigid tanks constrained at the base are considered. Analysis is performed for both tall and broad tanks to compare their behavior under seismic excitation. Efforts are made to quantify the percentage of base shear carried by membrane action and the consequent procedures that must be followed for safe design of liquid containing storage structures.

• KCI Concrete Journal
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• 제14권3호
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• pp.121-129
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• 2002

This study investigates experimentally into the design factors and quality variations having an effect on the properties of the combined high flowing concrete to be poured in the slurry wall of Inchon LNG in-ground receiving terminal. Especially, high belite cement and lime stone powder as cementitious materials and viscosity agent in order to improve self-compaction and hydration heat are used in this study. Water-cement ratio(W/C), fine aggregate volume ratio(Sr) and coarse aggregate volume ratio(Gv) as design factors of the combined high flowing concrete are applied to determine the optimum mix design proportion. Also quality variations for sensitivity test are selected items as followings. (1)Surface moisture(5cases) and (2)Fineness modulus of fine aggregate(5cases), (3)Concrete temperature(3cases), (4)Specific surface(3cases) and particle size of lime stone powder. As experimental results, water-cement ratio, fine and coarse aggregate volume ratio are shown as the optimum range 51%, 43% and 53% separately considering site condition of slurry wall. Also quality factors by sensitivity test should be controlled in the following ranges. (1) Surface moisture :to.67% and (2)Fineness modulus 2.6$\pm$0.2 of fine aggregate, (3)Concrete temperature l0-20t, (4) Specific surface 6,000$\textrm{cm}^2$/g and particle size 9.7$\pm$1.0${\mu}{\textrm}{m}$ of lime stone powder. Based on the results of this study, the optimum mix design proportion of the combined high flowing concrete are selected and poured successfully in the slurry wall of LNG in-ground tank.