• 제목/요약/키워드: Bituminous material

검색결과 32건 처리시간 0.025초

염청재료가 흙-시멘트의 강도 및 내구성에 끼치는 영향에 관한 연구 (A Study on the Effects of Bituminous Material on Durability of Soil-Cement Mixtures)

  • 김종옥;정하우
    • 한국농공학회지
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    • 제20권1호
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    • pp.4599-4613
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    • 1978
  • This study was intended to investigate the effects of bituminous material content of soil-cement mixtures on their durability. For the purpose, unconfined compressive strength test, Freeze-thaw test, and wet-dry test were performed with three types of soil. Each type of soil was mixed with three levels of cement content and each soil-cement mixture was mixed with four levels of bituminous material content. For the unconfined compressive strength test, Freeze-thaw test and wet-dry test, 324, 108, and 108-specimens were prepared respectively. Unconfined compressive strength was measured at age of 7-days, 14-days and 28-days using 108-specimens in each age. The soil-cement loss rate due to freeze-thaw and wet-dry were calculated after 12 cycles of test using 108-specimens in each test. The results are summarized as follows : 1. Optimum moisture content was increased with increase of cement content, but maximum dry density was changed irregulary with increase of the cement content. 2. The unconfined compressive strength was increased with increase of cement content, bituminous material content and curing age. Cement is more effective factor than bituminous material on unconfined compressive strength of soil-cement Mixture. 3. It is estimated as the most economical cement content that the recommended cement content of A.S.T.M. because increasing rate of unconfined compressive strength at age of 28-days was low when cement content is above the recommanded cement content of A.S.T.M. among all types of soil. 4. Although a portion of cement content is substituted for bituminous material, the necessary unconfined compressive strength can be obtained. 5. The soil-cement loss was more influenced by wet-dry than Freeze-thaw 6. The bituminous material is more effective on the decrease of soil-cement loss than increase of unconfined compressive strength 7. The void ratio of soil-cement mixture was changet irregularly with increase of cement content, but that was decreased in proportion to the increase of bituminous material content. 8. The regression equation between the unconfined compressive strength and soil-cement loss rate were obtained as table 7.

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아스팔트 포장층 분리억제용 역청재료의 부착성능 및 최적함량 평가에 대한 연구 (A Study of Evaluation for Optimum Content and Bond Strength Properties of Bituminous Materials applied for preventing Separation of Asphalt Pavement Layers)

  • 김도완;이상염;문성호
    • 한국도로학회논문집
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    • 제18권6호
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    • pp.137-143
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    • 2016
  • OBJECTIVES : Bituminous materials, such as tack coat, are utilized between pavement layers for improving the bond strength in pavement construction sites. The standards regarding the application of bituminous material are not clearly presented in the Korean construction guideline without RS(C)-4. Hence, the objective of this study is to determine the optimum content of bituminous materials by analyzing interlayer shear strength (ISS) from the direct shear tester, which was developed in this research. The shear strength of tack coat was defined with the sort of bituminous materials. METHODS : The mixtures for the shear test were made using marshall mix design. The specimens were vertically and horizontally separated for the direct shear test. The separated specimens were bonded using bituminous material. The objectives of the experiment are to determine the performance of bond and shear properties resulting from slippage, rutting, shovel, and corrugation of asphalt pavements. A machine based on the Louisiana interlayer shear strength tester (LISST) of NCHRP Report-712 was developed to determine the ISS. The applied types of tack coat were RS(C)-4, AP-3, QRS-4, and BD-coat with contents of $0.3{\ell}/m^2$, $0.45{\ell}/m^2$, $0.6{\ell}/m^2$, and $0.8{\ell}/m^2$, respectively. RESULTS : Table 2 gives the results of the direct shear test using the developed shear machine. The BD-coat type indicated the highest average ISS value compared to the others. Between the surface and binder course, optimum tack coat application rates for AP-3, RS(C)-4, QRS-4, and BD-Coat were $0.6{\ell}/m^2$, $0.3{\ell}/m^2$, $0.6{\ell}/m^2$, and $0.45{\ell}/m^2$, respectively. These optimum contents were determined using the ISS value. CONCLUSIONS : The ISS values of AP-3, RS(C)-4, and QRS-4 showed similar tendencies when ISS increased in the range $0.3{\sim}0.6{\ell}/m^2$, while ISS decreased when the applied rate exceeded $0.6{\ell}/m^2$. Similarly, the highest ISS value of the BD-coat was observed when the applied rate was $0.45{\ell}/m^2$. However, shear strength was similar to the maximum value of ISS when the tack-coat application rate of BD-Coat exceeded $0.45{\ell}/m^2$.

고려시대 선체출토 석탄의 재료학적 특성 및 국산 석탄과의 비교 연구 (Comparison Study for Domestic Coal and Material Characteristics of Coal from the Shipwreck of Koryo Dynasty)

  • 이장존;박석환;임성태;한민수
    • 보존과학회지
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    • 제29권4호
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    • pp.345-354
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    • 2013
  • 태안군 마도 해역 해저에서 인양된 마도 1호선의 선체 내 외부에서 출토된 석탄의 지구화학적 및 광학적, 광물학적 특성을 분석하였다. 연구 결과, 석탄의 비중은 $1.28g/cm^3$로 약 10%의 광물질 함유 상태를 고려하면 순수한 석탄만의 비중은 $1.15g/cm^3$ 정도이며, 갈탄과 유연탄 사이의 범위 해당된다. X-선 회절분석 결과는 peak점의 $2{\theta}$$20^{\circ}{\sim}23^{\circ}$ 사이로 낮은 탄화정도의 석탄에 해당되었으며, 석탄구성물질 분류에서 비트리나이트 군이 93~94%, 엑시나이트 군이 5~6%, 인어티나이트군이 1% 이었다. 또한 석탄의 비트리나이트 평균반사율은 $R_{mean}$: 0.627로 고휘발분역청탄 C(high volatile bituminous C coal) 또는 아역청탄 A(sub-bituminous A coal)에 해당된다. 공업분석 결과 미국 광무국의 기준에 의하면 아역청탄 A(sub-bituminous A coal) 또는 고휘발분역청탄 C(high volatile bituminous C coal)에 해당되며, 원소 분석 결과 역청탄에 해당되는 점결탄으로 분류된다. 마도1호선 석탄과 국내 석탄을 비교 분석 결과 포항 인근 장기지역의 갈탄과 유사하였다.

The Use of Bituminous Subballast on Future High-Speed Lines in Spain: Structural Design and Economical Impact

  • Teixeira, P.F.;Ferreira, P.A.;Pita, A. Lopez;Casas, C.;Bachiller, A.
    • International Journal of Railway
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    • 제2권1호
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    • pp.1-7
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    • 2009
  • The development of structural solutions for high-speed or very high-speed tracks that minimize total life cycle costs of the system is a key issue to improve the operational profitability of new investments. In opposition to conventional ballasted tracks, slab track solutions can be a cost-effective solution, but only in the cases where the benefits due to the increase in track availability and the reduction of track maintenance offsets its much higher construction costs. In the cases where such investment is not feasible, it is worth to evaluate possible structural improvements to ballasted track that allow reducing its maintenance needs without increasing too much its construction costs. This paper evaluates the design requirements and the impact of improving conventional high-speed ballasted tracks by using a bituminous subballast layer. It is divided into two main parts: first the design requirements of the structural solutions with bituminous subballast and its possible benefits on high-speed track deterioration, and secondly the evaluation of the economic impact, in terms of construction costs, of using this structural solution material in future Spanish high-speed lines.

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低質炭의 利用硏究 (第一報) 無燃固體燃料의 燃燒速度의 測定) (Studies on the Utilization of Low Quality Coals (1) Determination of combustion velocity of smokeless solid fuels)

  • 오신섭;김정혁
    • 대한화학회지
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    • 제4권1호
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    • pp.78-80
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    • 1957
  • Up to now, only superficial studies on the combustion velocity of smokeless fuels have been reported, while it should be a basical factor on the utilization of low quality coals and some other smokeless solid fuels. It was, therefore, difficult to choose raw material coals in manufacturing gaseous fuels. With the intent to solve above problem, we have determined combustion velocity of domestic anthracites, graphites, coalites of lignite and cokes from Japanese bituminous coal. The results show that the cokes from Japanese bituminous coal which has been used as raw material in the manufacturing gaseous fuels such as water gas, or producer gas in Korea can be replaced by some sources of domestic anthracite or coalite of lignite.

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화력발전소 비산회를 이용한 제올라이트합성 (Synthesis of zeolite from power plant fly ash)

  • 김재환;연익준;김광렬
    • 환경위생공학
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    • 제12권1호
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    • pp.49-58
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    • 1997
  • A study on the synthesis of zeolite from bituminous coal ESP fly ash as a raw material, which was emitted from the power plant, was carried out to reduce environmental problems and reuse of the industrial wastes. Bituminous coal fly ash was used as the source of silica and alumina. Zeolite was synthesized by hydrothermal reaction in aqueous NaOH solution with sodium aluminate as additive. The objective of this study is to elucidate the effect of several experimental variables on the synthesis of zeolite. The effects of preroasting temperature, mixing speed, leaching alkalinity, and molar ratio of Na$_{2}$O/SiO$_{2}$ and SiO$_{2}$/Al$_{2}$O of the products were investigated. The synthesized zeolite was proved to be NaA, which is known as 4A type, by comparing with SEM images, and X-ray diffraction analysis. And also we know that the transformation of zeolite A take places into other types of zeolites, i.e. Hydroxysodalite, zeolite P, with the variation of leaching alkalinity.

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유동층 연소로에서 유.무연탄 혼합 연소법을 이용한 국내산 저질 무연탄의 활용에 관한 연구 (A Study on the Use of Low-Grade Domestic Anthracite by Anthracite - Bituminous Coal Blend Combustion in a Fluidized Bed Combustor)

  • 정종현;조상원
    • 한국환경과학회지
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    • 제6권3호
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    • pp.267-276
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    • 1997
  • It has been studded that combustion and the production of air pollution of anthracite - bituminous coal blend In a fluidized bed coal combustor, The objects of thIns study were to investigate mixing characteristics of the particles as well as the combustibility of the low grade domestic anthracite coal and Imported h19h calorific bltununous coal in the fluidized bed coal combustor. They were used as coal samples ; the domestic low grade anthracite coal with heating value of 2,010kca1/kg and the Imported high grade bituminous coal with beating value of 6,520kca1/kg. Also, the effects of air flow rate and anthracite fraction on the reaching time of steady state condition have been studied. The experimental results are presented as follows. The time of reaching to steady state was affected by the temperature variation. The steady state time was about 120 minute at 300sc1h which was the fastest. It has been found that $O^2$ and $CO^2$ concentration were reached steady state at about 100 minute. It has been found that $O^2$ concentration decreased and $CO^2$ concentration increased as the height of fluidlzed bed Increased. It was found that splash zone was mainly located from 25cm to 35cm above distributor. Also, as anthracite traction Increased, the mass of elutrlatlon particles Increased, and $CO^2$ concentration decreased. As gk flow rate Increased,$O^2$ concentration decreased and $CO^2$ concentration increased. Regardless of anthracite fraction and flow rate, the uncombustible weight percentage according to average diameter of elutriation particles were approldmately high In the case of One Particles. As anthracite traction and k now rate Increased, elutriation ratio Increased. As anthracite fraction was increased, exit combustible content over feeding combustible content was Increased. Regardless of anthracite fraction, size distribution of Ued material from discharge was almost constant. Over bed temperature 85$0^{\circ}C$ and excess air 20% , the difference of combution efficiencies were little. It is estimate that the combustion condition In anthracite-bituminous coal blend combustion is suitable at the velocity 0.3m/s, bed temperature 85$0^{\circ}C$, the excess air 20%.

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저급탄 연소 석탄회의 미연물질 특성 분석 (Characteristics of Unburned Material Derived from Coal-fired Power Plant Burning Low Grade Coal)

  • 박호영;김영주;김태형;백세현;김경수;권달정
    • 에너지공학
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    • 제21권1호
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    • pp.68-74
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    • 2012
  • 국내 석탄화력발전소의 아역청탄과 역청탄의 혼소는 일반화되어 있으며 아역청탄의 비율이 무게 기준으로 50%가 넘는 경우도 있다. 저급탄인 아역청탄의 혼소 비율이 높아짐에 따라 연소 부산물인 비회에서 미연물질이 다량 발생하고 있으며 이는 콘크리트 혼화제로서의 비회 재활용을 가로막는 중요한 인자로 작용하고 있다. 본 연구에서는 아역청탄 혼소율이 높은 국내 500MW 표준 석탄화력발전소에서 미연물질이 포함된 비회를 입수하여 이에 대한 분석을 수행하였다. 이러한 미연물질은 석탄의 열분해 생성물인 검댕(soot)인 것으로 나타났으며 실제 석탄화력발전소에서 사용하고 있는 석탄과 혼탄의 성상 데이터와 CPD모델을 사용하여 혼탄별 검댕(soot)의 발생가능성을 분석하였다.

폐타이어를 이용한 지반동상 방지 (The Control of the Ground Frost Heave by Using the Scrap Tire)

  • 김영진;강병희
    • 한국지반공학회지:지반
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    • 제14권1호
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    • pp.49-58
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    • 1998
  • 폐타이어가 지반의 동상방지 건설재료로서 재사용될 수 있는지를 연구하였다. 동상방지에 대한 폐타이어의 기본적인 효과를 검토하기 위해 화강풍화토에 폐타이어가루를 몇 가지의 비율로 혼합해서 준비한 시료로서 영하 $17^{\circ}$하에서 동상시험과 화강풍화토에 대한 동결깊이시험을 실내에서 수행하였다. 역청포장의 보조기층 바로 아래에 폐타이어조각을 혼합한 쇄석층을 동상방지층으로 둠으로서 실용상으로 효과적이라는 사실을 알게 되었다. 그리고 이 동상방지 층의 소요두께와 동결 지수와의 관계식을 제안하였다.

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시멘트 및 콘크리트의 크롬분석 표준화에 관한 연구 (Standardization for $Cr^{+6}$ analysis in cement and concrete)

  • 박남규;송훈;추용식;이종규
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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    • pp.729-732
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    • 2006
  • Portland cement is presently the most widely used construction material. The process of manufacture of cement consists essentially of grinding the raw materials, mixing them intimately proportions and burning in a rotary kiln at a temperature of up to about $1450^{\circ}C$. Raw materials have used limestone, clay, silica, and iron oxide and fuel have used bituminous coal. Recently, A standpoint of the recycling of material resources, the production of cement use of industrial waste and residual products. Therefore, the final product of cement were included heavy metals such as $Cr^{+6}$ and Pb. The purpose of this study is standardization for $Cr^{+6}$ analysis in cement and concrete. From the comparative study of the examination method of $Cr^{+6}$ analysis, Japan cement association standard of $Cr^{+6}$ analysis is most suitable for the real state of affairs in korea.

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