• 한국지반환경공학회 논문집
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• 제24권6호
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• pp.13-20
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• 2023

본 연구는 강섬유(SF) 혼입률에 따른 고유동 흙막이 벽체 재료(RWM)의 역학적 성능 및 내구성을 평가하기 위한 것으로써, 흙막이 벽체 재료의 재료분리저항성, 유동성, 연행공기량을 확보하기 위하여 적정량의 고성능감수제(SP), 공기연행제(AEA) 및 증점 안정화제(VMA)를 사용하였다. 흙막이 벽체 재료 경화체의 압축 및 쪼갬 인장강도를 소정의 재령에서 측정하였으며, 흙막이 벽체 재료의 역학적 성능은 표면전기저항성 및 흡수율 실험을 통하여 고찰하였다. 또, 염소이온 침투저항성 및 동결융해 저항성 실험을 통하여 흙막이 벽체 재료의 내구성능을 고찰하였다. 실험결과에 의하면, 강섬유를 적용한 배합이 강섬유 무혼입 배합에 비하여 우수한 성능을 나타내었으며, 2% 적용 배합이 경제성 및 성능 관점에서 상대적으로 효과적인 것으로 관찰되었다. 따라서, 적절한 SF의 적용은 흙막이 벽체 재료의 성능 향상에 기여할 것으로 판단된다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 가을 학술발표회 논문집
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• pp.345-350
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• 1999

In this study the results of investigation on the physical and mechanical properties of a rockfill dam body were provided. On the crest of the old Namgang dam to be excavated partially, various in-situ tests(boring with SPT, sampling of undisturbed sample, field density test, field permeability test) and geophysical investigation works were performed Rock materials, i.e., shale and sandstone, were collected, and their slake durability was evaluated using slaking durability testing method which is suggested by ISRM.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 봄 학술발표회 논문집
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• pp.88-93
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• 1995

The purpose of this study is to investigate the mechanical properties and durability of high-quality concrete containing silica fume. For this purpose, the optimum quantity of silica fume were obtained for high-quality concrete, and the mechanical properties and durability of it are analyzed according to amount of combined material.

• International Journal of Concrete Structures and Materials
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• 제7권4호
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• pp.287-293
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• 2013

Strength and some durability properties of concrete containing rice husk ash (RHA) predominantly composed of amorphous silica at a specific surface of 235 $m^2/kg$ produced using a charcoal incinerator were determined. The maximum ordinary Portland cement (OPC) replacement with the RHA increased with increase in water/binder (w/b) ratio of the concrete mixes. The results show that 15 % OPC could be substituted by the RHAwithout strength loss at w/b ratio of 0.50. The split tensile strength generally increased with increase in RHA content for the mixes.

• 한국건설순환자원학회논문집
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• 제2권4호
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• pp.297-306
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• 2014

Recently nano-materials are gaining more importance in the construction industry due to its enhanced energy efficiency, durability, economy, and sustainability. Nano-silica addition to cement based materials can control the degradation of the fundamental calcium-silicate-hydrate reaction of concrete caused by calcium leaching in water as well as block water penetration and therefore lead to improvements in durability. In this paper, the influence of synthesized nano silica from locally available rice husk on the mechanical properties and corrosion resistant properties of OPC (Ordinary Portland Cement) has been studied by conducting various experimental investigations. Micro structural properties have been assessed by conducting Scanning Electron Microscopy, Thermo gravimetry and Differential Thermal Analysis, X-Ray Diffraction analysis, and FTIR studies. The experimental results revealed that NS reacted with calcium hydroxide crystals in the cement paste and produces Calcium Silicate Hydrate gel which enhanced the strength and acts as a filler which filled the nano pores present in concrete. Hence the strength and corrosion resistant properties were enhanced than the control.

• 한국해양공학회지
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• 제12권3호통권29호
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• pp.31-41
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• 1998

Single fiber fragmentation technique was used to evaluate the change of interfacial properties by degradation of fiber tensile strength in the fiber reinforced composites. The influences of fiber tensile strength on the interfacial properties have been evaluated by the fragmentation specimens(weak fiber samples) of glass fiber/epoxy resin that was made using the pre-degraded glass fiber in distilled water at $80^{circ}C$ for specified periods. The effects of the immersion time on the interfacial properties in the distilled water at $80^{circ}C$ also have been evaluated by the fragmentation specimens(original fiber samples) of glass fiber/epoxy resin that was made using the received glass fiber. As the result, the tensile strength of glass fiber was decreased with the increasing of the treatment time in the distilled water at $80^{circ}C$ and the interfacial shear strength was independent of the change of the glass fiber strength in the single fiber fragmentation test. But in the durability test using the single fiber fragmentation specimen, interfacial shear strength decreased with the increasing of the immersion time in distilled water ar $80^{circ}C$. And it turned out that the evaluating of interfacial shear strength using original fiber tensile strength was valuable in the durability test for the water environment by the single fiber fragmentation technique.

• 자원리싸이클링
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• 제16권6호
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• pp.20-27
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• 2007

순환골재를 콘크리트용 골재로 활용하기 위한 연구의 일환으로 2종류의 순환골재를 천연골재 중량의 0, 25, 50, 75 및 100%의 5단계로 혼입한 시멘트 경화체를 제조한 후 시멘트 경화체의 내구 특성을 평가한 결과, 골재의 특성에 따라서 시멘트 경화체의 성능이 상이하게 나타나는 것으로 확인되었다. RAB의 경우 RAA에 비하여 부착 모르타르 및 흡수율이 작아서 혼입율 50%까지는 모든 시험 항목에서 천연골재와 거의 유사하거나 약간 작은 값을 나타내었으며, 향후 순환골재를 콘크리트 구조용 골재로 사용하기 위해서는 순환골재에 부착된 모르타르량을 최대한 제거하고, 천연골재에 25%까지 혼입하여 사용해도 무관할 것으로 판단된다.

• 한국세라믹학회지
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• 제52권2호
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• pp.140-145
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• 2015

In this study, we verified the relationship among the electrical conductivity, chemical durability, and structure of conductive vanadate glass in which $BO_3$ and $BO_4$ and $V^{4+}$ and $V^{5+}$ coexist simultaneously. We prepared samples of vanadium borophosphate glass with various compositions, given by $50V_2O_5-xB_2O_3-(50-x)P_2O_5$(x = 0 ~ 20 mol%) and $70V_2O_5-xB_2O_3-(70-x)P_2O_5$(x = 0 ~ 10 mol%), and analyzed the electrical conductivity, chemical durability, FT-IR spectroscopy, thermal properties, density, and molar volume. Substituting $B_2O_3$ for $P_2O_5$ was found to improve the electrical conductivity, chemical durability, and thermal properties. From these results, we can draw the following conclusions. First, the electrons shift from the electron rich $V^{4+}$ to the electron deficient $BO_3$ as the $B_2O_3$ content increases. Second, the improvement in chemical durability and thermal properties is attributed to an increase in cross-linked structures by changing from a $BO_3$ structure to a $BO_4$ structure.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.443-444
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• 2009

본 연구는 고내구성 혼화재를 모르타르에 적용하여 기초물성과 염소이온 침투저항성을 비교 검토 후 최종적으로 해양환경하의 고내구성 콘크리트를 개발하는데 그 목적을 두었다.

• 한국정밀공학회지
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• 제14권12호
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• pp.135-142
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• 1997

New approach to determine thd design of automotive tire profile was introduced. In this study, design technology for tire profile was combined with a finite element method to improve high speed durability. Static and dynamic behavior analysis of new concept tire was compared with conventional tire profile. To obtain the improved tire performance, appropriate design values, ie. design methodology, section profile selection, material properties, are needed.