• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.190-191
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• 2013

In this research, the fundamental experiment for colour concrete(by using pigment) has been invested. Fundamental properties and dyeability for the colour mortar as the changing replacement ratio of pigment has been tested. For the conclusion, with the increasing ratio of pigment, the flow and compressive strength for the mortar has been decreased, For the dyeability, there's little difference when replacement ratio of dyestuff changed when the colour is red and yellow, but large difference when the blue pigment was used. Consider about the workability and strength of the mortar, the optimum pigment's replacement ratio is fixed as 2.5%.

• 콘크리트학회논문집
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• 제21권1호
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• pp.55-64
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• 2009

본 연구는 시멘트 종류에 따른 병용계 자기충전 콘크리트의 최적배합비를 도출하고, 최적배합비의 품질특성을 평가하여 현장시공의 자료로 제안하기 위한 것이다. 병용계 자기충전 콘크리트는 분체와 증점제를 함께 사용하기 때문에, 품질의 안정성을 확보할 수 있을 것으로 예측된다. 분체로써 점성 증대 및 수화열 저감에 우수한 석회석 미분말을 사용하였다. 석회석 미분말의 치환율은 시멘트 종류에 따른 구속수비 실험을 통해 정하였으며, 배합변수는 잔골재용적비 ($S_r$), 굵은골재 용적비 ($G_v$) 및 물-시멘트비 (W/C)로 하여, 최적배합비를 도출하였으며, 이에 대한 응결시간, 블리딩량, 침하량 및 수화열 특성을 분석하였다. 실험결과, 고로슬래그 시멘트의 경우에는 석회석 미분말의 치환율 13.5%, 잔골재 용적비 47%, 물-시멘트비 41%이며, 저열포틀랜드시멘트의 경우에는 석회석 미분말의 치환율 42.7%, 잔골재 용적비 43%, 물-시멘트비 51%이며, 굵은골재 용적비는 시멘트의 종류에 관계없이 53%로 나타났다. 최적배합비에 대한 응결시간, 블리딩, 침하량 및 수화열에 대한 실험 결과, 저열포틀랜드시멘트를 사용한 자기충전 콘크리트가 가장 안정적인 것으로 나타났으며, 설계기준강도 40.0 MPa (배합강도 51.5 MPa)를 만족하는 저열포틀랜드시멘트를 사용한 병용계 자기충전 콘크리트를 지하식 LNG 저장탱크의 지하연속벽용 콘크리트로 제안하였다.

• 한국지반공학회논문집
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• 제16권4호
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• pp.117-128
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• 2000

모래다짐말뚝(SCP)공법은 느슨한 모래지반이나 연약한 점성토지반을 압밀촉진시키고 지지력을 강화하여 지반을 개량할 목적으로 적용되는 개량공법이다. 이 연구에서는 연약지반개량을 위해 점토지반에 모래다짐말뚝을 사용하는 경우에 지반개량목적에 부합되는 적절한 치환율($a_s$)을 결정하기 위해 치환율 변화에 따른 모형토조시험과 대형직접전단시험을 실시하였다. 원형모형토조를 이용한 실내시험에서는 20%, 30%, 40%, 50%, 60% 의 치환율로 모래다짐말뚝을 조성하여 모래다짐말뚝의 치환율과 복합지반의 응력분담비, 침하저감효과의 한계를 규명하였다. 또한, 대형직접전단시험기를 이용하여 치환율 20%, 30%, 46% 의 복합지반에 대하여 치환율이 복합지반 강도에 미치는 영향도 조사하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권2호
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• pp.291-298
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• 2012

While attempting to develop low salt, low fat and high fibre chicken nuggets, the effect of partial (40%) common salt substitution and incorporation of chickpea hull flour (CHF) at three different levels viz., 5, 7.5 and 10% (Treatments) in pre-standardized low fat chicken nuggets (Control) were observed. Common salt replacement with salt substitute blend led to a significant decrease in pH, emulsion stability, moisture, ash, hardness, cohesiveness, gumminess and chewiness values while incorporation of CHF in low salt, low fat products resulted in decreased emulsion stability, cooking yield, moisture, protein, ash, color values, however dietary fibre and textural properties were increased (p<0.01). Lipid profile revealed a decrease in total cholesterol and glycolipid contents with the incorporation of CHF (p<0.01). All the sensory attributes except appearance and flavor, remained unaffected with salt replacement, while addition of CHF resulted in lower sensory scores (p<0.01). Among low salt, low fat chicken nuggets with CHF, incorporation CHF at 5% level was found optimum having sensory ratings close to very good. Thus most acceptable low salt, low fat and high fibre chicken nuggets could be developed by a salt replacement blend and addition of 5% CHF.

• Advances in concrete construction
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• 제13권3호
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• pp.233-242
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• 2022

An attempt is made to develop an eco-friendly concrete with ground granulated blast furnace slag (GGBS) and pond ash as partial replacement materials for cement and fine aggregate, respectively without compromising the strength and durability. Sixteen concrete mixes were developed by replacing cement and fine aggregate by GGBS and pond ash, respectively in stages of 10%. The maximum replacement levels of cement and fine aggregates were 50% and 30% respectively. Experimental results revealed that the optimum percentage of GGBS and pond ash replacement levels were 30% and 20% respectively. The optimized mix was used further to study the flexural behavior and durability properties. Reinforced Concrete (RC) beams were cast and tested under a four-point bending configuration. Also, the specimens prepared from the optimized mix were subjected to alternate wet and dry cycles of acid (3.5% HCl and H₂SO₄) and sulphate (10% MgSO₄) solutions. Results show that the optimized concrete mix with GGBS and pond ash had a negligible weight loss and strength reduction.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.145-145
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• 2021

Water distribution networks (WDNs) are designed to satisfy water requirement of an urban community. One of the central issues in human history is providing sufficient quality and quantity of water through WDNs. A WDN consists of a great number of pipelines with different ages, lengths, materials, and sizes in varying degrees of deterioration. The available annual budget for rehabilitation of these infrastructures only covers part of the network; thus it is important to manage the limited budget in the most cost-effective manner. In this study, a novel pipe replacement scheduling approach is proposed in order to smooth the annual investment time series based on a life cycle cost assessment. The proposed approach is applied to a real WDN currently operating in South Korea. The proposed scheduling plan considers both the annual budget limitation and the optimum investment on pipes' useful life. A non-dominated sorting genetic algorithm is used to solve a multi-objective optimization problem. Three decision-making objectives, including the minimum imposed LCC of the network, the minimum standard deviation of annual cost, and the minimum average age of the network, are considered to find optimal pipe replacement planning over long-term time period. The results indicate that the proposed scheduling structure provides efficient and cost-effective rehabilitation management of water network with consistent annual budget.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.981-982
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• 2010

• Advances in concrete construction
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• 제6권2호
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• pp.103-121
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• 2018

This paper reports the effects of coarse and fine recycled concrete aggregates (RCA) on fresh and hardened properties of self-compacting concrete (SCC) containing ground granulated blast-furnace slag (GGBFS) as cement replacement. For this purpose, three SCC mixes groups, were produced at a constant water to binder ratio of 0.38. Both fine and coarse recycled aggregates were used as natural aggregates (NA) replacement at different substitution levels of 0%, 25%, 50%, 75% and 100% by volume for each mix group. Each group, included 0, 15% or 30% GGBFS as Portland cement replacement by weight. The SCC properties investigated were self-compactability parameters (i.e., slump flow, T500 time, V-funnel flow time, L-box passing ability and sieve stability), compressive strength, capillary water absorption and water penetration depth. The results show that the combined use of RCA with GGBFS had a significant effect on fresh and hardened SCC mixes. The addition of both fine and coarse recycled aggregates as a substitution up to 50% of natural aggregates enhance the workability of SCC mixes, whereas the addition from 50 to 100% decreases the workability, whatever the slag content used as cement replacement. An enhancement of workability of SCC mixes with recycled aggregates was noticed as increasing GGBFS from 0 to 30%. RCA content of 25% to 50% as NA replacement and cement replacement of 15% GGBFS seems to be the optimum level to produce satisfactory SCC without any bleeding or segregation. Furthermore, the addition of slag to recycled concrete aggregates of SCC mixes reduces strength losses at the long term (56 and 90 days). However, a decrease in the capillary water absorption and water permeability depth was noticed, when using RCA mixes with slag.

• Asian-Australasian Journal of Animal Sciences
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• 제23권12호
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• pp.1626-1631
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• 2010

An experiment was conducted to evaluate the effect of dietary replacement of normal maize (NM) with quality protein maize (QPM) on performance, immune response and carcass characteristics of broiler (Krishibro) chickens. Six experimental diets were prepared separately for starter and finisher phases. Diet 1 was a control diet formulated with NM and soybean meal. In diets 2-5, the NM was replaced with QPM at 25, 50, 75 and 100%, respectively. Diet 6 was the same as the control diet, but supplemented with synthetic lysine similar to the industry standard. Each test diet was fed to 8 replicates, each of 5 chicks, reared in stainless steel battery brooders. The AME content of QPM (3382 kcal/kg) was similar to that of NM (3,352 kcal/kg), but protein (9.91 vs. 8.94%), lysine (0.40 vs. 0.26%) and tryptophan (0.09 vs. 0.07%) contents of QPM were higher than NM. Dietary replacement of NM with 50% QPM significantly (p<0.05) improved body weight gain, feed conversion ratio, humoral immune response, relative bursa weight, and breast muscle yield and lowered abdominal fat content. No further improvement in these parameters was recorded by increasing the level of replacement of NM with QPM to either 75% or 100%. Further, the improvement noticed in the 50% QPM group was similar to the group fed the NM diet with lysine supplementation, and thus dietary replacement of NM with QPM at 50% did not need extra synthetic lysine supplementation. It is concluded that dietary replacement of NM with QPM at the 50% level resulted in optimum performance, higher breast muscle yield and higher immune response in broiler chickens.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2006년도 춘계학술논문 발표대회 제6권1호
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• pp.19-22
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• 2006

The quantity of Recycled concrete powder is increased, because it hal been ever so often crushing for production of a good quality recycled aggregates This Study is on the Development of Concrete-Product by Using Recycled Concrete Powder and alto for know performance of concrete-producted having low water contents and it is to know for all of performance of concrete-producted having low water contents The conclusions of this study are following. The use of replacement cement is not effective, because it has strengh of less than 10MPa But It is possible to develop high strength concrete-producted having 39MPa above compressive strength by using recycled concrete powder. Because strength enhancement effects by recycled concrete powder are responsible to optimum grading. The conclusions of this study are following. The use of replacement cement is not effective, because it has strengh of less than 10MPa. It is possible to develop high strength concrete-producted having 39MPa above compressive strength by using recycled concrete powder. Because strength enhancement effects by recycled concrete powder are responsible to optimum grading.