• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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• pp.71-72
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• 2015

As this study is the one related to the ultra high strength concrete essentially used for high rise buildings, it has analyzed on the flowability of ultra high strength concrete according to the variation of coarse aggregate and fine aggregate. The coarse aggregate was planned as two types including Granite Aggregate (GA) and crushed coarse Limestone Aggregate (LA) while fine aggregate was planned as four types including Sea Sand (SS), Limestone Crushed Fine Aggregates (LFA), Electric Arc Furnace Oxidizing Slag Aggregates (EFA) and Crushed Sand (CS) to perform experiment with a total of eight variables. As a result of analyzing slump flow, 500mm concentration time, U-Box and L-Flow, etc. among the characteristics of fresh concrete, a mix using LA+LFA is determined to show high flowability in case of applying ultra high strength concrete.

• 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.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표회 논문집(I)
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• pp.173-178
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• 1998

This study is described the experimental result of the development of artificial aggregate using paper sludge ash and the application of it in concrete. Artificial aggregates are prepared with crushed stone in the variety aspect. Therefore, Quality properties of artificial aggregate using paper sludge ash are fairly corresponded with it of crushed stone. For the application of artificial aggregate using paper sludge ash in concrete, Coarse aggregates are replaced with artificial aggregate using paper sludge ash in the constant of volume(0%, 30%, 70%, 100%). It is conclued from the test results that the artificial aggregate using paper sludge ash could be used replacement of coarse aggregate in concrete. Continuous study should be planned for improvement of it's quality.

• 콘크리트학회지
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• 제7권1호
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• pp.136-144
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• 1995

근래 양질의 하천골재가 거의 고갈상태에 직면함에 따라 쇄석골재의 사용이 보편화되고 있는 우리나라의 실정에 비추어 볼 때 골재의 화학반응에 대한 연구의 필요성이 점차 증대되고 있다. 본 연구에서는 우리나라에서 실제 쇄석골재를 생산하는 238곳 중 63곳의 시료골재를 채취하여 화학적, 광물학적, 모르터 바 분석실험을 실시하여 골재의 화학반응성을 규명하였다. 분석시험 결과 대부분의 시료골재가 화학반응성을 나타내지 않았으나 광물학적 분석에서 유해광물로 알려진 성분들이 여러 시료골재에 포함되어 있었다. 따라서 해사의 사용 등 점차 화학반응 환경이 공존하게 되면 골재의 화학반응이 일어날 가능성이 커지므로 계속적이고 심도있는 연구가 요구되고 있다.

• 한국산업융합학회 논문집
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• 제2권1호
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• pp.45-52
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• 1999

It is difficult to keep the balance of supply and demand for natural aggregates in recent years, because natural resources have become to be almost exhausted. Crushed stone is already used for coarse aggregate instead of river gravel at present. Now, crushed sand or sea sand should be used for fine aggregate, because natural sand also has been exhausted with a few exceptions around Nakdong River. The sea sand has a lot of problems which are the corrosion of reinforcement bars, the investment of facility for cleansing salt and the cost increase due to the insufficiency of industrial water. Therefore, it is necessary to produce and to utilize the crushed sand very actively, but some material properties which are related to water absorption, strength and chemical durability, prevent from determining the generalized criteria because its rocks make much differences in its physical and chemical characteristics. In this paper, fundamental physical properties of crushed sand, which comes from Daegu Subway construction fields, have been investigated for the usability on basic material of concrete. The optimum replacement ratio and the strength estimation method of crushed sand replacing natural sand also have been presented here through the compressive strength test of ready-mixed concrete cylinders.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.339-342
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• 2000

Recently, the importance of the conutermeasures for waste materials has pointed out. Waste glass is also one to waste materials used for the recycling in construction sites. The crushed waste glass has been used to make a glass polymer composite that can be applied for sewer, storm drain pipe and interlocking block, etc. In this study, the crushed waste glass is explored with the possibility of recycling it, as a substitute for fine aggregates. The prepose of this investigation is to improve the strengths and acid resistance of the UP mortars using crushed waste glass. The UP mortars are prepare with blast furnace slag fly ash filler. the UP-fine aggregate ratios the crushed waste glass replacements for fine aggregate are tested strengths before and after immersion(H (아래첨자2)SO(아래첨자4) 10%), weight change and acid resistance are also tested. From the test results, the relative strength or UP mortars using fly ash as filler are found to be somewhat superior to that of the UP mortars using blast furnace as filler, And a UP mortar with fly ash as a filler, a UP-fine aggregate ratio of 15% and a waste glass replacement if 50% for fine aggregate is recommended as optimal mix proportion of UP mortar using crushed waste glass. Accordingly, it is enough to assure the use of the crushed waare glass as an aggregate for the production of UP mortar.

• 한국농공학회지
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• 제44권2호
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• pp.107-116
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• 2002

The amount used of aggregates for concrete is increasing rapidly since the mid-1980s in Korea. The natural gravels from river are already displaced with crushed stone, and use of crushed sand as a substitute of natural river sands, also, is getting increased day by day. This paper is presented fur analysis on mechanical properties of high strength concrete using fly ash and crushed sand. The material functions in mixing design of concretes are various water-cement ratios(w/c) such as 0.25, 0.40, 0.55 and different replacement ratio of crushed sand to natural sands such as 0%, 20%, 40%, 60%. As a results, it has been shown that compressive strengths of concretes with W/C lower than 0.40 and 0.25 are higher than 400 kgf/$\textrm{cm}^2$ and 600 kgf/$\textrm{cm}^2$ respectively. It is also concluded that the results of rapid chloride permeability tests of concrete are evaluated to negligible. The conclusions of this study is that it is possible to use fly ash and crushed sand fur high strength concrete.

• 한국세라믹학회지
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• 제51권5호
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• pp.492-497
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• 2014

Artificial fine aggregates (denoted AFA) were fabricated using spent bleaching clay (denoted SBC) generated from processed vegetable oil and stone sludge (denoted SS) produced from crushed aggregate manufacturing materials for use as functional construction materials. Each raw material was crushed to particle size finer than $150{\mu}m$, and fine spherical pellets of approximately 1 ~ 4 mm in diameter were prepared by a pelletizing process. The physical properties of the AFA were measured with different types of sintering equipment. A new type of vertical furnace that sinters fine aggregates in a fluidized bed at high temperatures was designed and tested. AFA sintered in a rotary kiln at $1125^{\circ}C$ showed a bulk density of $1.5g/cm^3$ and a water absorption of 16%. AFA sintered in the vertical furnace at $1125^{\circ}C$ showed a bulk density of $1.9g/cm^3$ and water absorption of 8.5%. The bulk density of the AFA sintered in the vertical furnace showed a bulk density 27% higher and water absorption 47% lower than those of AFA sintered in the rotary kiln.

• 한국건설순환자원학회지
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• 제14권2호
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• pp.28-34
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• 2019

• 한국건설순환자원학회지
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• 제16권2호
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• pp.56-61
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• 2021