• Title/Summary/Keyword: 최적 배합비

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A Study of Field Mixing Ratio using Bio-grouting Injection Material (바이오그라우팅 주입재를 이용한 현장 배합비에 관한 연구)

  • Park, Ilehoon;Kim, Daehyeon
    • Journal of the Korean Geosynthetics Society
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    • v.16 no.2
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    • pp.47-54
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    • 2017
  • This study aims to develop a bio-grouting material in a powder form like cement. Sand gel samples were produced with the ratio of sodium silicate No.3 to water (50 : 50, 35 : 65, 20 : 80), and the ratio of cement to bio-grouting material (100 : 0, 90 : 10, 70 : 30) to select a mixing ratio of bio-grouting, respectively, and then analyzed the geltime over time. The uniaxial compressive strength was evaluated to select and suggest a mixing ratio optimized for construction conditions. The indoor test reveals that preferred geltime and uniaxial compressive strength is obtained in 35 : 65 with respect to the ratio of sodium silicate No.3 to water, and 90 : 10 with respect to the ratio of cement to bio-grouting material to demonstrate best optimal mixing ratios.

Optimum Mix Design for Waste Newsprint Paper Fiber Reinforced Cement Composites (폐지섬유보강 시멘트 복합체의 최적배합비 도출)

  • 원종필;배동인;박찬기;박종영
    • Journal of the Korea Concrete Institute
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    • v.13 no.4
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    • pp.346-353
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    • 2001
  • This research investigates the mixture proportioning of waste newsprint paper fiber for thin-cement product. Waste newsprint paper fibers obtained through shredded mechanically by a dry process. Waste newsprint paper fiber reinforced cement composites was manufacted by slurry-dewatering method. The waste newsprint paper fiber reinforcement conditions (fiber mass fraction, level of substitution of virgin fibers, level of fiber beating) and processing variables (pressed, unpressed) are optimized through experimental studies and statistical analyses based on factorial design of experiments and analyses of variance. The optimized recycled waste newsprint paper fiber reinforced cement composites were technically evaluated. The results are shown to possess acceptable properties and strong potentials of the recycling of waste newsprint paper of the reinforcement of thin-cement products.

Application of Performance Based Mixture Design (PBMD) for High Strength Concrete (고강도 콘크리트의 성능기반형 배합설계방법)

  • Kim, Jang-Ho Jay;Oh, Il Sun;Phan, Duc Hung;Lee, Keun Sung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.6A
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    • pp.561-572
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    • 2010
  • This paper is a study about application of recently proposed Performance Based Mixture Design (PBMD) for design of high strength concrete (HSC) to obtain HSC mix proportion that satisfies required performances. The PBMD method which uses Satisfaction curve based on a Bayesian method is a performance oriented concrete mix proportion design procedure easily applicable to any condition and environment for a possible replacement to the current prescriptive design standards. Based on extensive experimental results obtained for various materials and performance parameters of HSC, the application feasibility of the developed PBMD procedure for HSC has been verified. Also, the proposed PBMD procedure has been used to perform application examples to obtain desired target performances of HSC with optimum concrete mixture proportions using locally available materials, local environmental conditions, and available concrete production technologies. The validity and precision of HSC mix proportion design obtained using the PBMD method is verified with the experimental and ACI presented results to check the feasibility for actual design usage.

Determination of Optimal Mixture Proportion of Segregation Reducing Type Superplasticizer for High Fluidity Concrete (고유동 콘크리트용 분리저감형 유동화제의 최적배합비 결정)

  • 한천구;김성수;손성운
    • Journal of the Korea Concrete Institute
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    • v.14 no.3
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    • pp.275-282
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    • 2002
  • High fluidity concrete needs high dosage of superplasticizer to acquire sufficient fluidity and high contents of fine powder and viscosity agents to prevent segregation. But it requires high manufacturing cost and has difficult in quality control. Therefore, in this paper, determination of optimal mixture proportion of segregation type superplasticizer for high fluidity concrete and manufacturing high fluidity concrete by applying developed segregation reducing type superplasticizer are discussed using flowing concrete method. According to test results, as dosage of superplasticizer increases, it shows that fluidity and bleeding increase, while air contents and ratio of segregation resistance decrease. It also shows that adding viscosity agent into it reduce bleeding and improve segregation resistance. Dosage of AE agent into it containing viscosity agent recovers loss of air contents during flowing procedure. Combination of proper contents of superplasticizer, viscosity agent and AE agent make possible to develope segregation reducing type superplasticizer Compressive strength of high fluidity concrete applying flowing method with it is higher than that of base concrete. No differences of compressive strength between compacting methods are found.

A Study on the Characterization of Geotechnical Properties in Permeable Barriers Mixture of Bentonite, Loess, and Sand (벤토나이트·황토·모래를 혼합한 투수벽체의 지반공학적 특성에 관한 연구)

  • Chun, Byung-Sik;Park, Jae-Woo
    • Journal of the Korean GEO-environmental Society
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    • v.6 no.4
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    • pp.5-12
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    • 2005
  • In this study, the geotechnical applicability of permeable barriers that could filter the leachate from a landfill was evaluated. Specimens were cast from sand, loess and bentonite according to the specific weight ratios of them. A series of experiments are performed to determine the unconfined compressive strength and permeability of various mixing ratio of bentonite, loess, and sand. From the laboratory test, optimum mixing ratio that satisfied the regulations of unconfined compressive strength($5kgf/cm^2$) and coefficient of permeability ($10^{-3}{\sim}10^{-4}cm/sec$) in landfill was found when the weight ratio of sand and loess was 8:2 with 2% of bentonite. Using the laboratory test data and in situ test results, the applicability of the wall will be tested for various conditions.

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Development of Combination Runoff Model Applied by Genetic Algorithm (유전자 알고리즘을 적용한 혼합유출모형의 개발)

  • Shim, Seok-Ku;Koo, Bo-Young;Ahn, Tae-Jin
    • Journal of Korea Water Resources Association
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    • v.42 no.3
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    • pp.201-212
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    • 2009
  • The Tank model and the PRMS(Precipitation Runoff Modeling-modular System) model have been adopted to simulate runoff data from 1981 to 2001 year in the Seomgin-dam basin. However, the simulated runoff by each single model showed some deviations compared with the observed runoff, respectively. In this study a genetic algorithm combination runoff model has been proposed to minimize deviations between simulated runoff and observed runoff that should yield from single model such as Tank model or PRMS model. The proposed combination runoff model combining the simulated respective output of the Tank model and the PRMS model is to produce the optimum combination ratio of each single model applying to the genetic algorithm which may yield the minimum deviations between simulated runoff and observed one. The proposed combination runoff model has been applied to the Seomgin-dam basin. It has also been shown that the combination model by introducing optimal combination ratio should yield less deviations than single model such as the Tank model or the PRMS model.

Improvement Effectiveness of Soft Ground Using Hardening Agent (고화재 혼합처리를 이용한 연약지반개량효과)

  • Chun, Byung-Sik
    • Journal of the Korean GEO-environmental Society
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    • v.2 no.2
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    • pp.59-64
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    • 2001
  • Recently, the application of shallow mixing method using hardening agent has increased because of the advantage of securing trafficability, reducing the working period, solving environmental problems caused by dumped and replaced soil, etc. In this paper, three types of representative hardening agents in Korea are used to achieve the optimum of ground improvement. 1he unconfined compression tests are carried out with specimens under various mixing ratios and curing periods of hardening agent to assess the stabilizing ability. The unconfined strengths on site were estimated with various mixing ratios based on the results of the laboratory tests. It was estimated that the improved strength on site was higher than that of the required strength $5.0kgf/cm^2$.

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Elastic and excellent moisture transmittance is developing bio-laminated fabric for footwear (투습방수성이 우수한 신발용 바이오 라미네이팅 소재개발)

  • Gwon, O-Kyeong;Kim, Jong-Hwan;Park, Seon-Hwa;Kim, Seung-Jin;Hong, Jong-Yun
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2008.10a
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    • pp.109-110
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    • 2008
  • 본 연구에서는 신축성이 우수한 친수형 무공 PET필름을 사용해서, 소취성, 보온성 및 투습방수성이 우수한 신발용 소재를 개발하였다. 이상의 목적을 달성하기 위해서 최적 소재의 선정, PET필름의 특성평가, 최적 라미네이팅 공정조건 확립, 첨가제 선정 및 가공조건 확립 등에 대해서 실험고찰을 하였으며, 얻어진 주요 결과는 다음과 같다. (1) 신발의 갑피용 및 안창용 최적소재로서 경편직물을 선정하였으며, PET필름의 최적 요구특성은 내수성 9460mmH2O, 투습성 10,000g/m2/24hrs, 인장강도42kgf/cm2, 신도249% 였다. (2) Hot-melt 라미네이팅 공정에서의 투습방수성을 좌우하는 Dot roll No, Coating gap의 최적조건은 CP75(Engraved dot roll no), -0.2mm(Coating Unit gap) 였다. (3) EVA base polymer 및 기타 조제의 최적 배합비를 확립하고 이를 바탕으로 compound를 제조하여 Press로 molding하여 안창용 Sponge를 얻었다. (4) 안창 sponge 위에 점착된 knit 소재의 소취효과는 우수하였으며, 갑피용 투습방수 경편직물의 보온성도$15{\sim}20%$로 우수하였다.

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A Study on Characteristics of Hydraulic Conductivity in the Soil-Bentonite Mixed Soils with Compaction Energy and Swelling in the Landfill (폐기물매립장에서 다짐에너지와 팽윤도에 의한 토양-벤토나이트 혼합토의 투수계수 특성에 관한 연구)

  • 이종민;이재영
    • Journal of Soil and Groundwater Environment
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    • v.6 no.4
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    • pp.61-72
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    • 2001
  • A barrier liner system is placed at the bottom and side slope in landfill to protect a leaking of leachate that the hydraulic conductivity of this system should be less than It 107cm/sec. In this study, the soil-bentonite mixture for the bottom liner system was evaluated in two point of views : changing characteristics of the hydraulic conductivity according to the different mixing ratio of soil-bentonite with the effect of bentonite swelling and the difference method (A & D type) of compaction on the hydraulic conductivity. As the results, maximum dry density (${\gamma}$$_{dmax}$) of SC group mixture was higher than of CL group mixture. However, the result of optimum moisture contents(OMC) of both groups were the contrary. In case of ${\gamma}$$_{dmax}$ by different compaction method, D type was higher than A. But the OMC were the contrary. The difference of ${\gamma}$$_{dmax}$ according to the Compaction energy, “SC” group mixture W3S higher than the “CL” group. In case of OMC of “CL” group was higher than “SC” group. The effecting of swelling was a little bit different on the two factors. According to the result of compaction test, the use of site soil only could not meet the criteria on hydraulic conductivity, but could find a solution for the mixing ratio of bentonite mixture were satisfied to the standard of barriation. The increased in bentonite mixing ratio and degree of swelling, the values of hydraulic conductivity were decreased. Especially the “CL” group with “D” type compaction measured the lowest value with the same conditions. Also, the bentonite mixing ratio has more influenced on the hydraulic conductivity compare with swelling effect. The “SC” group mixture with “A” typo compaction got a big difference from others. The evaluation of economic for the construction cost on the two cases, the lower bentonite mixing ratio of soil-bentonite mixed soil is more economically because of bentonite cost.

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