• Title/Summary/Keyword: 건설성능

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The Chloride Ion Diffusivity of Ready-Mixed Concrete Depending on Specified Compressive Strength (레디믹스트 콘크리트의 설계기준 압축강도별 염소이온 확산특성)

  • Park, Dong-Cheon;Kim, Yong-Ro
    • Journal of the Korea Institute of Building Construction
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    • v.18 no.6
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    • pp.543-550
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    • 2018
  • The RC buildings which are constructed on the seaside are followed by KBC(2016) to achieve the minimization of durability damage. To control the corrosion of the reinforcing steel bar by salt attack, W/C should be under 0.4 and specified concrete strength is higher than 35MPa in the concrete/building construction standard specification. Even though it has been proved that the concrete mixed with mineral admixture such as blast furnace slag and fly ash etc. have high strength and durability in previous researches, the beneficial informations are not applied to the codes. Ready-mixed concretes which usually include the admixtures in Busan were tested to certify the salt attack durability. In the same specified concrete strength, remarkable salt attack durability was evaluated in comparison to OPC. For economical and reliable durability design, chloride ion diffusivity should be measured before applying to new building construction.

A Study on the Development of Installation and Management of Safety Shower (Safety shower 설치 및 관리기준 개선에 관한 연구)

  • Lee, Dong Hyeok;Yoo, Byung Tae
    • Journal of the Korean Institute of Gas
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    • v.22 no.6
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    • pp.1-7
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    • 2018
  • Currently chemical plant risk have been issued by occurring frequent accidents. Accidents can be generally composed of fire, explosion, release in chemical plant. In case of fire and explosion, accident victims are occurred immediately after accident but release accident, late emergency response cause damage to worker. Especially, there are many victims by late emergency response against chemical exposure to skin. In case of chemical exposure to skin, irreversible damage like death, blindness, burn can be prevented by washing immediately. Safety shower can provide the cleaning for chemical exposure to eye, skin. Most of chemical plants are built in 1980s so equipment become superannuated. In this reason, safety shower also cannot operate normally in emergency situation. Therefor safety shower should be managed by installation and management guideline. This study perform the establishment guideline for safety shower installation and inspection to increase the reliability.

Influence of Sulfate on Thermodynamic Modeling of Hydration of Alkali Activated Slag (알칼리 활성 슬래그의 열역학적 수화모델링에 대한 황산염의 영향)

  • Lee, Hyo Kyoung;Park, Sol-Moi;Kim, Hyeong-Ki
    • Resources Recycling
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    • v.28 no.1
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    • pp.32-39
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    • 2019
  • The present study investigated hydration of alkali activated slag incorporating sulfate as a form of anhydrite by employing thermodynamic modeling using the Gibbs free energy minimization approach. Various parameters were evaluated in the thermodynamic calculations, such as presence of sulfide, precipitation/dissolution of AFt/AFm phase, and the effect of oxic condition on the predicted reaction. The calculations suggested no significant difference in the void volume and chemical shrinkage, which might influence the performance of the mixtures, in spite of various changes of the parameters. Although the types of hydration products and their amount varied according to the input conditions, their variations were smaller range than that induced by water-to-binder ratio. Moreover, it did not affect the amount of C-(N-)A-S-H which was the most important hydration product.

Improvement of Satellite Ocean Information Service for Offshore Marine Industry (연근해 해양산업을 위한 위성해양 정보 서비스 개선방안)

  • Cho, Bo-Hyun;Lee, Gun-Wook;Kim, Dong-Chun;Yang, Keum-Cheol;Kim, SG;Yo, Seung-jae
    • Convergence Security Journal
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    • v.18 no.1
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    • pp.85-91
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    • 2018
  • In this study, we design a marine environmental information service system with satellite images based on satellite images to reduce the damage caused by changes in the marine environment. The system provides satellite oceanographic information such as water temperature, chlorophyll, float, etc. as hierarchical texts, which is implemented as a unit module Web service so that it can be expanded in OpenAPI environment. And stability of system plug-in portability, service hours, data extraction precision and speed are used as a basis for diagnosing service stability. By securing the function and performance of the service system implemented in this study, it can be expanded to a complex technology that can customize the users by group by adding not only general services of existing systems operated by location but also information about a specific interested areas. Especially, various other items of interest including marine environment information are developed in modules, so we expect to be able to expand and service the system by plugging into the system and to spread it in technical linkage with the related institution information system.

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Seismic Capacity according to Structural System of High-rise Apartment (고층 아파트 구조시스템에 따른 내진성능 분석)

  • Lee, Minhee;Cho, So-Hoon;Kim, Jong-Ho;Kim, Hyung-Do
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.32 no.3
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    • pp.149-154
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    • 2019
  • The structural system of domestic high-rise apartments can be divided into two parts; the core wall system, which is composed of walls concentrated in the center and the shear wall system, which comprises a great number of walls distributed in the plan. In order to analyze the lateral behavior of each system, buildings with typical domestic high-rise apartment plans were selected and nonlinear static analysis was performed to investigate the their collapse mechanism. From the force-displacement relation derived from nonlinear static analysis, response modification factor was evaluated by calculating the overstrengh and ductility factor, which are important in the seismic response. The ductility of core wall system is small, but as it is governed by wind load, its overstrength is greatly estimated, and its response modification factor is calculated by the overstrengh factor. Due to a large number of walls, shear wall system has a large ductility, making the response modification factor considerably large.

Study of Characteristics of Clay Roof Tiles Using Ferro Nickle Slag Recycled Resources (페로니켈슬래그 순환자원을 활용한 점토기와의 성능평가)

  • Kim, Soon-Ho
    • Journal of the Korea Institute of Building Construction
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    • v.21 no.4
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    • pp.281-291
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    • 2021
  • To reduce the environmental load of the construction industry, there is a need to minimize construction and demolition by strengthening the eco-friendliness of building materials and extending the durable lifespan. Therefore, while many Hanok roof finishing methods have been proposed to address these problems, the current trend is to use the existing method due to issues such as economic feasibility, weight, and durability. The manufacturing method of clay roof tiles used as roofing materials for Hanok buildings is optimized by using a mixture of 64.5% Gyeongju clay, 15.0% kaolin, 15.0% FNS(Ferro Nickel Slag), and 5.5% MAS(Magnesia Aluminum Silicate) under optimal conditions. The results of the experiment involving firing at 1,125℃ showed that flexural strength of 12,102N, which is higher than the standard of KS F 3510, an absorption rate of 6.08%, a volume specific gravity of 2.15g/cm3, and the freeze-thaw properties were satisfied. A method for securing stable quality was studied.

The Evaluation of Pullout Resistance and Installation Damage according to the Shape of Flexible Strip Reinforcement (신장형 띠형 보강재의 형상에 따른 인발저항 및 시공성능 평가 실험 연구)

  • Jeoung, Jaehyeung;Kim, Jaehong
    • The Journal of Engineering Geology
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    • v.31 no.3
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    • pp.321-332
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    • 2021
  • Though development of reinforced earth wall is on the rise recently, safety verification for various methods remains behind which has caused the problems including collapse after installation. This study aims to evaluate the field applicability of the shape of flexible strip reinforcement according to pullout resistance test and field damage test. The test specimens were 3 shape of reinforcement, the typical flexible band reinforcement, developed luged band reinforcement, and band type reinforcement made by cutting geogrid. It was found that reinforcement of type have strengths and weaknesses, respectively. The best type of flexible strip reinforcements can be selected, if the conditions are considered with the installation conditions of the reinforcing earth retaining wall and the particle size of the backfill materials.

Performance Evaluation of Combined Sewer Overflow Treatment using Filtration Pilot Device (파일럿 여과장치를 이용한 합류식하수관 월류수 처리성능 평가)

  • Lee, Jun Ho;Shin, Young Gyun
    • Journal of Korean Society on Water Environment
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    • v.35 no.5
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    • pp.409-417
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    • 2019
  • In this study, a $480m^3/day$ pilot device was constructed through laboratory experiments based on the Ministry of Environment manual. The purpose of this study was to analyze the characteristics of CSO treatment and backwashing characteristics by applying the pilot device to the field. The purpose of this study was to acquire the basic data necessary for the design and operation management of the real scale filtration type non-point pollution control system. The filtration was conducted while maintaining the linear velocity of 20m/hour. The CSO treatment efficiencies of the pilot devices were 0.4-76.1%(mean 49.0 %), SS 51.4-91.6%(mean 77.8%), COD 22.2-59.4% (mean 38.3%) and TP 14.5-52.6%(mean 38.1%),respectively. The correlation coefficient between SS and the turbidity of influent water was 0.90, higher than that of CSO. To operate the treatment system effectively, the turbidity can be easily measured in real time as the monitoring item is the most appropriate because SS is the main target substance of the non-point source. As a result of analyzing the adsorbent treatment characteristics of PP filter material applied to this pilot device, the average particle diameter range of influent was $4.6-40.1{\mu}m$(mean $21.2{\mu}m$) and the treated water was $0.9-24.5{\mu}m$(mean $6.4{\mu}m$), respectively. Particles of approximately 10m or less are leached out, and so it is necessary to compensate for the raw water containing micro particulate matter.

Study on the Seismic Performance for Low-rised RC Building with Vertical and Torsional Irregularities (수직비정형과 비틀림비정형을 동시에 가지는 저층 RC 건물의 내진성능에 관한 연구)

  • Choi, In-Hyuk;Baek, Eun-Rim;Lee, Sang-Ho
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.12
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    • pp.137-148
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    • 2019
  • Korean piloti-type buildings are comprised of pilotis in the first story and shear walls in the upper stories. This vertical irregularity causes excessive lateral plastic deformation on the first story while the upper stories stay elastic. Meanwhile, asymmetric position of structural components such as core walls and columns of RC piloti-type buildings tends to produce torsional irregularities of the structures. Korean Building Code(KBC2016) requires the special seismic load and torsional amplification factor to apply to the piloti-type buildings lower than six-story or 20m if it has vertical and torsional irregularities when the building corresponds to seismic design category C or D. Many Korean low-rised RC buildings fall into the class. Therefore, the special earthquake load and torsional amplification factor are often applied to a building simultaneously. However, it has not been studied enough how much influence each parameter has on buildings with vertical and torsional irregularities at the same time. The purpose of this study is to evaluate the effect of factor special seismic load and torsional amplification on seismic performance of irregular buildings. In this study, a damaged 4th story piloti-type building by the Pohang earthquake was selected and the earthquake response analysis was carried out with various seismic design methods by the KBC 2016. The effect of the design parameters on seismic performance was analyzed by the dynamic analysis of models with special seismic load and torsional amplification factor based on the selected building. It was concluded that the application of the torsional amplification factor to the reference model to which special seismic design was applied, does not significantly affect the seismic performance.

Decision Making Methods for Types of Roadside Non-point Pollution Reduction Facilities and Its Application (도로비점오염 저감시설의 유형선정방법 개발 및 적용)

  • Cho, Hye Jin
    • Ecology and Resilient Infrastructure
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    • v.7 no.4
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    • pp.256-261
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    • 2020
  • Roadside non-point pollution reduction facilities are classified as infiltration, vegetation, reservoir, and wetland types based on their respective pollution reduction mechanisms. However, without a detailed analysis of the road and traffic conditions it is very difficult for civil engineers to determine which category of pollution reduction facility is best suited to their planning requirements. To address this issue, we propose a new decision-making method for the selection of roadside non-point pollution reduction facilities. The principal factors informing the proposed decision-making methods are the road characteristics, including location, structure, number of lanes, and traffic volume. As a result of the study, a total of new pollution reduction plans were developed, with their selection conditions and the corresponding applicable facilities established. The effectiveness of the proposed pollution reduction schemes was demonstrated for roads in Kyounggi-do, providing a valuable basis for future pollution reduction plans.