• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.31-34
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• 2003

Sandwich panel is composed of the facing sheets which support the external load, the cellular core with the low thermal conductivity and the adhesive agent to bond them. The cellular core was produced by binding lightweight cellular aggregates with cement and two types of acrylic base St/BA emulsion were added with a view to improving the workability ion due to high absorption of light weight aggregate and to develope more strength, respectively. This investigation is to comprehend the effect of the addition of two types of St/BA on thermal conductivity, calorific value and exhaustion content of noxious gas in addition re compressive and flexural strength. Flexural strength of the specimen made with St/BA-2 ranged 20kgf/cm2 to 25kgf/cm2 and was about 50% to 100% as high as that of the non-fiber specimen. Thermal conductivity was recorded from 2.0 to 3.0 kcal/mh$^{\circ}C$ and calorific value of St/BA modified specimen was much lower than that of commercial sandwich panel core of EPS and urethane. Careful caution has to be taken because generation of noxious gas such as CO, NO and SO2 tend to increase with addition of polymer cement ratio.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.453-456
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• 2005

The use of lightweight concrete products is usually increased at a recently high structures. Among the rest EPSB concrete products which have an excellence on the sound and thermal insolation are used. Also, the gathering of nature aggregate is limited, so that lack of fine aggregate is appearing. The purpose of this study is to obtain basic data of properties of EPSB concrete in according to types of aggregate. The results of experiment are as follow. The EPSB concrete using bottom ash is appeared the lowest slump in fresh concrete. The EPSB concrete using river sand and bottom ash are showed as a similar compressive strength except it using crushed sand in hardened concrete.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.111-112
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• 2023

With the development of cities, the density of the population is continuously increasing as buildings become larger and more high-rise, but since the Haeundae residential complex fire in Busan in 2010, there has been a growing need to meet the fire protection performance of buildings as large-scale fires continue to occur every year. On the other hand, fire doors, which are one of the fire protection performance of buildings, have been judged unqualified in 82% of cases when fire doors constructed on the actual site were inspected after completion. The reason for this is that paper honeycomb and glasswool, which are used as core materials for fire doors, absorb moisture, reducing thermal insulation performance, and sagging due to increased weight, leading to performance degradation due to warping in empty spaces. To overcome these problems, research is underway to apply lightweight aerated concrete, an inorganic material, as a core material. Therefore, in order to select a blowing agent that produces stable bubbles prior to the production of lightweight bubble concrete for application as a fire door inner core, this study examined the physical performance according to the type of blowing agent and dilution concentration, and the following conclusions were drawn. Compared to vegetable bubbles and independent bubbles, synthetic bubbles have 3~8% higher thermal conductivity than independent bubbles, but 3~6% lower slurry density than vegetable bubbles, and 2~13% higher compressive strength, which is thought to be an improvement of synthetic bubbles.

• KIEAE Journal
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• 제15권4호
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• pp.45-52
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• 2015

Purpose: Foam concrete is the concrete that contains large amount of air voids inside. In general, the density of foam concrete depends on parameters like water/binder ratio, foam volume, aggregate and pozzolan content, etc. Method: In this study, the effect of foam volume and fly ash content on dry density is investigated intensively in order to find the relationship between each parameter and their abilities to counteract with each other. According to the above information, though there are quite a number of studies on the effect micro fiber on foam concrete at low volume fractions, there is still lack of information especially on the high fiber content side. The objective of the second study is to investigate further on the use of micro fiber at higher volume fraction and fill in the lacking information. Beside from this study, the investigation of the effect of micro-fiber (polypropylene) to enhance the properties of foam concrete is also carried out. Result: Of the two variables that are investigated in this study, the foam volume and the fly ash content, show significant effect on the properties of foam concrete. The foam volume tends to decrease the density and strength of foam concrete. In the second part of our study, a large fibre volume fraction is proved to be able to evidently increase the flexural strength of foam concrete up to about 40% due to the effect of fibre bridging over the crack and a significant number of fibres that intercepts the crack surfaces. However, the compressive strength is found to decrease severely due to the occurrence of large pores as the result of fibre being added into concrete mixture.

• 한국건축시공학회지
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• 제9권5호
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• pp.63-70
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• 2009

본 연구는 실리카와 칼슘의 수열합성 반응에 의해 제조하는 흡음형 경량기포콘크리트의 개발에 관한 일련의 연구이다. 원료는 석탄화력발전소의 부산물로 발생되는 바텀애시를 미분화한 것을 실리카원으로 사용하였고, 1종보통포틀랜드시멘트, 알루미나 시멘트, 소석회를 칼슘원으로 사용하였다. 경화체 내에서 연속기포를 형성하기 위하여 기포제를 이용하여 발포한 기포를 슬러리와 혼합한 후 몰드에 타설하는 선발포 방식으로 시험체를 제조하였다. 실험인자는 물분체비, 기포제 희석비, 기포 혼입비로 설정하였고 이들 요인이 흡음형 기포콘크리트의 압축강도, 절건밀도, 전공극률, 연속공극률, 흡음성능에 미치는 영향을 검토하였다. 실험결과 기포콘크리트의 흡음성능은 거의 모든 실험 수준에서 흡음재료를 위한 NRC의 요구성능을 만족하는 것으로 나타났다. 기포비는 가장 지배적인 인자이고 이 연구에서 기포콘크리트의 모든 특성에 현저하게 영향을 끼치는 것으로 나타났다. 물분체비는 압축강도와 절건밀도 뿐만 아니라 전공극률과 연속공극률에 거의 영향을 끼치지 않았고 기포제 희석비는 거의 모든 특성에 영향을 주지 않았다. 흡음성능과 흡수시간 및 연속공극률의 상관관계 분석결과 흡수시간은 연속공극률과의 상관성이 높은 것으로 나타났다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.255-260
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• 2003

The corrosion of steel rebars has been the major cause of the reinforced concrete deterioration. It is FRP rebar that is developed to solve problem of such steel rebar. FRP rebar in concrete structures should be used as a substitute of steel rebars for that cases in which aggressive environment produce high steel corrosion, or lightweight is an important design factor, or transportation cost increase significantly with the weight of the materials. But FRP rebar have only linearly elastic behavior; whereas, steel rebar has linear elastic behavior up to the yield point followed by large plastic deformation and strain hardening. Thus, the current FRP rebars are not suitable concrete reinforcement where a large amount of plastic deformation prior to collapse in required. The main objective of this study was to develop new type of hybrid FRP rebar. The manufacture of the hybrid FRP rebar was achieved pultrusion, braiding and filament winding techniques. Tensile and interlaminar shear test results of hybrid FRP rebar can provide its excellent tensile strength-strain behavior and interlaminar stress-strain behavior.

• 산업진흥연구
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• 제6권4호
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• pp.1-9
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• 2021

본 연구는 정수슬러지의 활용을 위하여 경량골재를 제조하고, 그 물성을 확인하기 위하여 경량골재의 특성과 그 활용가능성을 확인하는 것이다. 경량골재 원료로써 특성을 알아보기 위하여 화학조성 및 열적 특성에 대하여 검토하였다. 급속소성법을 이용하여 골재를 소성하고 물성을 측정하였다. 정수슬러지는 높은 강열감량을 가지고 있었으며, 높은 내화도를 가지고 있었다. 정수슬러지를 30wt% 첨가하였을 때 1,150~1,200℃의 온도에서 경량화되는 것을 확인할 수 있었고, 1200℃이상의 온도에서 밀도 0.8이하의 초경량골재도 제조할 수 있었다. 일반골재를 대체하여 콘크리트에 적용 시 28일 강도가 200~600kgf/cm²를 갖는 공시체를 얻을 수 있었으며, 여과재 시험 시 일반모래와 동등 이상의 성능을 나타냈다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.269-274
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• 2001

The purpose of this study is to evaluate basic properties of artificial aggregate using concrete sludge according to mixing ratio. Cement, waste phosphogypsum and Powder of blast furnace slag are used with binder of artificial aggregate. Specific gravity, absorption are tested for basic property, and impacting, abrasion and crushing tests are done for characteristics of strength on the aggregate, including comparison with crushed stone. Bry specific gravity was ranged about 1.16 to 1.30 the test result of the aggregates and shape is round In the result of tests, it is concluded that qualities of the aggregates using concrete sludge are slightly lower than crushed stone but it is similiar with sintering artificial lightweight aggregate in high temperature.

• KIEAE Journal
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• 제7권5호
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• pp.121-126
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• 2007

This is the experimental study on the functional property of the light-weight concrete according to the mineral composite. According to the increase of the functional mineral, Autoclaved light-weight concrete (ALC) have a effect of high far infrared ray, deodorization, anion and change of chromaticity on D65 of light source. Compressive strength and change of specific gravity by foaming of Mixed Slurry in accordance with additive rates and Water. It chracterizes surface by SEM, chemical component and crystallization by XRD, XRF. the results of this experiment studied influences of ALC by functional minerals.

• 한국전산구조공학회논문집
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• 제16권1호
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• pp.53-58
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• 2003

탄소섬유쉬트는 경량, 고강도, 우수한 내식성, 그리고 간편한 시공성 때문에 많은 종류의 철근콘크리트 부재의 보강에 사용되고 있다. 그러나 탄소섬유쉬트에 의해 보강된 철근콘크리트 부재의 파괴거동은 탄소섬유쉬트와 콘크리트 표면의 부착특성에 따라 크게 달라진다. 본 연구에서는 탄소섬유쉬트와 콘크리트 사이의 경계면에 링크요소를 이용함으로써 탄소섬유쉬트와 콘크리트 사이의 부착거동의 변화를 고려한 부착응력-미끄럼 모델을 제안하였다. 또한 이 방법의 유효성을 알아보기 위하여 탄소섬유쉬트로 보강된 철근콘크리트 보의 파괴거동에 대한 해석을 실시하여 실험결과와 비교하였다. 그 결과 본 연구에서 제안된 모델을 이용한 해석결과는 실험결과와 비교적 잘 일치함을 알 수 있었다.