• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2006년도 춘계학술논문 발표대회 제6권1호
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• pp.115-118
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• 2006

Nowadays the using of concrete is generalized, and construction material is demanded to be lightweight according to increasing the height and capacity of buildings. Therefore, it needs to develop the products having the great quality and various performance. Extruding concrete panel made of cement, silica source, and fiber, and it is a good lightweight concrete material in durability and thermostable. The silica of important ingredient is natural material with hish SiO2 contents and difficult in supply because of conservation of environment. On the other hand, the stone powder sludge discharged about 20-30% at making process of crushed fine aggregate and it is wasted. The stone powder sludge is valuable instead of silica ole because the stone powder sludge includes water of about 20-60%, SiO2 of about 64% and it has fine particles. This experiment is on the properties of extruding concrete panel using the stone powder sludge use instead of silica. From this experiment, we find that it is possible to replace the silica as stone power sludge up to 50%,

• 콘크리트학회지
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• 제8권5호
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• pp.171-178
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• 1996

본 연구는 소도로 포장용 재료로서 재생콘크리트의 역학적 특성과 성능을 규명하였다. 재생콘크리트는 굵은 골재의 반을 재생골재로 대치하여 제조되었고 이와 함께 천연 잔골재와 유동화제 그리고 플라이애쉬(각각 시멘트 중량의 0.8% 및 5%)가 사용되었다. 실험을 통하여 재령28일 재생콘크리트의 휨강도, 압축강도, 탄성계수 및 파괴인성은 약 $45kg/cm^2$, $250kg/cm^2$, $230,000kg/cm^2$ 및 $0.863 MPa{\cdot}m^{1/2}$으로 나타났고 또한 6개월 지난 후 이 압축강도 및 파괴인성이 크게 향상되었다. 결론적으로 재생콘크리트는 역학적으로 도시나 농촌지역 소도로의 콘크리트 포장 재료로 충분히 적용 가능한 특성을 가진 것으로 판단되었다.

• 한국농공학회지
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• 제41권6호
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• pp.90-96
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• 1999

Over 4.1 billion metric tons of non-hazardous solid wstes are generated in the United States annually. Therefore, there is a need to reuse or reprocess as many products or by-products as possible. In this report, theaggregates produced from Naval Shipyard and Charleston area dredge spoils are designated as GP-21-23 and GP 4-5, repectively. The major objective of this study is to determine the feasiblity of the use of these aggregates in concrete. The followings are some of the conclusions, observations and recommendations regarding this portion of the research project. In most cases, the unit weight of concrete containing GP 21-23 and GP 4-5 (vitrified galss) lower than the control concrete, and the concrete containing vitrified glass produced lower compressive and bending strength compared to the control. However the concrete containing virtrified glass could be used in the field based on the minimum criterial set for the mix design. The use of vitrified glass in concrete is recommended in several applications except parking lots, side walks and main roads, because abrasion resistace is not high.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 봄 학술발표회 논문집
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• pp.57-64
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• 1996

Lately, rapid expansion of construction industry and following increment of demand for concrete in the construction created shortage of aggregates in the nation. Supplement of good quality aggregate is an immediate issue for the construction industry to solve. Therefore, this study evaluated a possibility of using coal mine waste collceted from Kwangwon-do region as a source of aggregate in manufacturing polymer concretes which have high strength and high durability. First, aggregates were obtained by crushing coal mine waste and polymer concrete was manufactured using these aggregate. Mechanical property test results for the polymer concrete showed that the coal mine waste aggregates were acceptable to use as a replacement of the aggregate in polymer concrete manufacture.

• International Journal of Concrete Structures and Materials
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• 제7권3호
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• pp.193-202
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• 2013

Geopolymer mortar compressed blocks were prepared using fly ash, ground granulated blast furnace slag, silica fume and metakaolin as binders and sand/quarry dust/pond ash as fine aggregate. Alkaline solution was used to activate the source materials for synthesizing the geopolymer mortar. Fresh mortar was used to obtain the compressed blocks. The strength development with reference to different parameters was studied. The different parameters considered were fineness of fly ash, binder components, type of fine aggregate, molarity of alkaline solution, age of specimen, fluid-to-binder ratio, binder-to-aggregate ratio, degree of saturation, etc. The compressed blocks were tested for compression at different ages. It was observed that some of the blocks attained considerable strength within 24 h under ambient conditions. The cardinal aim was to analyze the experimental data generated to formulate a phenomenological model to arrive at the combinations of the ingredients to produce geopolymer blocks to meet the strength development desired at the specified age. The strength data was analyzed within the framework of generalized Abrams' law. It was interesting to note that the law was applicable to the analysis of strength development of partially saturated compressed blocks when the degree of saturation was maintained constant. The validity of phenomenological model was examined with an independent set of experimental data. The blocks can replace the traditional masonry blocks with many advantages.

• Earthquakes and Structures
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• 제11권3호
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• pp.461-481
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• 2016

The research described in this paper investigates the seismic behaviour of lightly reinforced concrete (RC) bearing sandwich panels, heavily conditioned by shear deformation. A numerical model has been prepared, within an open source finite element (FE) platform, to simulate the experimental response of this emerging structural system, whose squat-type geometry affects performance and failure mode. Calibration of this equivalent mechanical model, consisting of a group of regularly spaced vertical elements in combination with a layer of nonlinear springs, which represent the cyclic behaviour of concrete and steel, has been conducted by means of a series of pseudo-static cyclic tests performed on single full-scale prototypes with or without openings. Both cantilevered and fixed-end shear walls have been analyzed. After validation, this numerical procedure, including cyclic-related mechanisms, such as buckling and subsequent slippage of reinforcing re-bars, as well as concrete crushing at the base of the wall, has been used to assess the capacity of two- and three-dimensional low- to mid-rise box-type buildings and, hence, to estimate their strength reduction factors, on the basis of conventional pushover analyses.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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• pp.267-268
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• 2010

본 연구에서는 알칼리 활성화 모르타르의 제조에 있어서 바텀애쉬의 결합재로서의 활용가능성을 파악하기 위해 각 구성재료가 미치는 영향을 강도 및 유동성 측면에서 파악하였다.

• 콘크리트학회논문집
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• 제17권3호
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• pp.335-342
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• 2005

천연 건설자원이 고갈되어감에 따라, 심각한 환경오염을 일으키고 있는 각종 산업폐기물의 재활용을 통해 새로운 건설소재를 개발하기 위하여, 폐플라스틱과 폐 콘크리트를 재활용한 폴리머콘크리트의 역학적 특성을 분석하였다. 본 연구에서는 폐 PET를 재생한 불포화 폴리에스테르 수지를 재생골재와 결합시켜, 재생골재 및 수지변화량에 따른 역학적 특성과 내화학성 실험을 실시하였으며 실험결과, 재생수지 및 골재를 사용한 폴리머콘크리트(RPC)의 강도는 수지의 함량이 증가함에 따라 차츰 증가하는 추세를 보였다. 하지만 어느 수지량의 한계점 (대략 $13{\~}17\%$)에선 더 이상의 강도증가는 나타내지 않고 있음을 확인할 수 있었다 또한 재생골재 함량이 증가할수록 강도와 탄성계수는 감소하였으나 수지량 $17\%$에서는 이러한 현상이 나타나지 않았다. 선형대수회귀 분석을 통해 수지량 $9\%$일 때의 압축강도와 휨, 할렬 인장강도의 상관관계를 확인한 결과 높은 신뢰도를 보임을 알 수 있었다. 하지만 수지량이 증가함에 따라 뚜렷한 상관관계가 나타나지 않는 경향을 나타내었다. 재생골재를 사용한 폴리머콘크리트의 내화학성에 따른 중량변화와 강도실험은 비교적 산과 염에 강한 특성을 나타내었다. 그리고 염산 $30\%$의 수용액에선 알칼리수용액 $40\%$ 보다는 강한 저항성을 나타내었음을 압축강도 및 중량변화를 통해 확인할 수 있었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.335-340
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• 2002

By the recently, Environmental pollution is serious by the highly economic growth and expansion of lively country basic industry. Especially, in case of industrial waste and life waste leaped into a pollution source. Also, research for processing of waste and recycling countermeasure is a pressing question on national dimension because it is prohibited an ocean disposal and reclamation. In this study, it looked for fracture characteristic value of recycling a coal ash to decrease environmental pollution by picky and exhaustion of natural resources and to reduce self-weight to prepare for a tall building and earthquake. So a coal ash examined to be possible to do as construction material. It achieved compressive strength test and three points bending test with initial notch depth rate and age for variables to show a basic research data. From the basis of the three points bending test, the fracture parameters - notch sensitivity, fracture energy, initial compliance were experimentally proposed. From the results of the compressive strength test, the elastic modulus was experimentally proposed. Also on the basis of the three points bending test, the fracture parameters - notch sensitivity, fracture energy, initial compliance were experimentally proposed. The results that the strength and fracture energy value are lower than concrete or mortar is described in this paper. Also, it shows that the deflection at fracture decreases as the age increases and the notch sensitivity decrease. However, it is judged to be available to construction material if research is continuously gone forward.

• 한국구조물진단유지관리공학회 논문집
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• 제20권3호
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• pp.33-41
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• 2016

콘크리트는 내화재료로서 우수한 성능을 발휘하지만 화재가 지속됨에 따른 재료특성 변화 또는 성능저하의 위험을 갖는다. 이 연구는 실물모형 철근 콘크리트 (RC) 보를 활용하여 비재하 화재 실험을 수행하여 화재노출 전후의 콘크리트 및 보강철근의 재료특성을 실험적으로 분석한 연구이다. 화재실험에 사용된 보는 길이 4 m의 RC 보로서 KS F 2257 화재실험 규격에 따라 시험 체를 제작 및 화재실험을 수행하였다. 화원의 가력은 ISO 834의 표준화재 곡선을 사용하였으며 보 가열부에서의 온도를 계측하고자 하면 및 측면에 열전대를 설치하였다. 실험결과, 화재에 노출된 화재 코어 공시체의 경우 약 11 MPa로 약 66%의 강도저하가 발생하였다. 화재에 직접 노출된 철근의 경우 노출되지 않은 철근에 비해 약 17%에 해당하는 75 MPa의 항복강도 저하를 나타낸 것으로 분석되었다. 철근의 경우 콘크리트라는 내화피복에 의하여 보호되어 약 4시간의 화재 실험에서도 온도는 한계온도의 최댓값인 $649^{\circ}C$를 크게 상회하지 않는 것으로 나타났다.