• 제목/요약/키워드: slag cement mortar

검색결과 261건 처리시간 0.024초

시멘트 모르타르의 황산염 침식 저항성에 대한 혼화재의 영향 (Effects of Admixture to Sulfate Attack Resistance of Cement Mortar)

  • 형원길;소승영;소양섭
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2000년도 봄 학술발표회 논문집
    • /
    • pp.704-709
    • /
    • 2000
  • This study is to test effects of sulfate attack on deterioration of cement mortar. Four tests have been carried out with four types of mortars mixed by ordinary portland cement and sulfate-resistant portland cement containing blast-furnace slag and fly-ash. It was immersed in sulfate solution for 7, 28, 91, and 180 days. from the test results, sulfate attack resistance of cement mortar was improved by admixtures (blast-furnace slag and fly-ash), sulfate-resistance portland cement mortar showed high resistance than ordinarily portland cement at compressive strength, and similar the resistance of sulfate attack with ordinarily portland cement mortar with admixtures.

  • PDF

석고 혼입 석탄가스화 슬래그 미분말 치환 시멘트 모르타르의 초기강도 특성 (Initial Strength Characteristics of Cementitious Gypsum-Containing Coal Gasification Slag Powder Replacement Cement Mortar)

  • 조현서;김민혁;이건철;조도영
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2019년도 춘계 학술논문 발표대회
    • /
    • pp.207-208
    • /
    • 2019
  • In this study, compressive strength was measured to evaluate the initial strength of cement mortar substituted with coal gasification slag containing desulfurized gypsum, and the reactivity of desulfurized gypsum was confirmed. In order to improve the reactivity, 2% gypsum mixed type and gypsum unfedged type specimens were fabricated and the influence of desulfurization gypsum on compressive strength of coal gasification slag and blast furnace slag fine powder replacement cement mortar was compared and confirmed. As a result of the experiment, it was confirmed that the initial compressive strength of the specimen containing the desulfurized gypsum was improved at the initial stage.

  • PDF

전기로 슬래그를 치환한 고로 슬래그 시멘트의 특성 (Properties of Blast Furnace Slag Cement Modified with Electric Arc Furnace Slag)

  • 이승헌;황해정;권성구
    • 한국세라믹학회지
    • /
    • 제43권7호
    • /
    • pp.408-414
    • /
    • 2006
  • Properties of slag cement that contained 50 wt% of blast furnace slag were studied when replaced blast furnace slag powder with electric arc furnace slag powder. Electric arc furnace slag was aged for about 2 months in the air by being crushed to be 1-3 mm in size. As a result of the experiment, it was proven that the water content for obtaining the same consistency became decreased as slag is replaced with electric arc furnace slag instead of blast furnace slag. Also, the workability of mortar increased about 30% at the same ratio of water to binder when blast furnace slag was completely replaced with electric arc furnace slag. The compressive strength of mortar on the 28 days increased when a slag replacement rate became 10 wt%, however, it rather decreased when the slag replacement rate exceeded 10 wt%. The heat of hydration became higher for the first 14 h in case of the replacement of slag cement by electric arc furnace slag. Yet, it decreased when 14 h had passed. Therefore, when all blast furnace slag was replaced with electric arc furnace slag, about 15 cal/g heat of hydration decreased when it passed about 72 h.

고로급냉슬래그를 활용한 투수성 모르타르의 공학적 특성에 관한 기초연구 (Engineering Characteristics of Permeable Mortar using Water-Quenched Blast Furnace Slag as Eine Aggregates)

  • 방윤경;박재로
    • 기술사
    • /
    • 제33권4호
    • /
    • pp.77-83
    • /
    • 2000
  • In this study, engineering characteristics of permeable mortar using water-quenched blast furnace slag as fine aggregates were analyzed by laboratory experiments to examine its suitability for permeable concrete pavement techniques. Engineering characteristics of mortar were investigated by performing both the compressive, flexural strength tests together with the constant head permeability tests for twenty-six types of mixing samples having different percetage of slag, cement and water. After 28days of curing, every performance was tested to find optimum mixture. When the go coefficient of permeability was 10$\^$-2/cm / sec and flexural strength was 30kg/㎠, we conclusion that the best mix design in permeable mortar was made in the condition,60% of cement and 20% of water percentage of unit slag contents. From the present investigations, it is concluded that suitability for permeable concrete pavement techniques using water-quenched blast furnace slag as fine aggregates may possibly be used to achieve effects on strength together with drainage effects.

  • PDF

Properties of reduced and quenched converter slag

  • Ko, In-Yong;Ionescu Denisa;T. R. Meadowcroft
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
    • /
    • pp.542-546
    • /
    • 2001
  • Converter slag has some compositional similarities to portland cement. But it has no hydration properties due to it's quite high concentrations of FeO(20-35%), MnO(4-6.5%). So it is needed to reduce the concentrations of iron and manganese of converter slag to use as cement additives by enhancing it's hydration properties. In this study, converter slag was modified it's composition by mixing of silica, alumina and quenched BF slag and reduced in induction furnace and quenched in running water. The hydraulic properties and structures of modified and quenched converter slag are significantly changed depend on the amount and kinds of additives. The addition of alumina up to 10% and BFQ slag up to 20% by weight on converter slag was effective to enhance the hydraulic properties of modified and quenched slag. The addition of reduced and quenched converter slag up to 20% by weight in replacement of portland cement in mixing of concrete mortar were shown higher compressive strength than 100% cement concrete mortar.

  • PDF

혼화재료가 공장제품용 시멘트 모르타르의 강도 및 동결융해 저항성에 미치는 영향 (Influence of Admixtures on Strengths and Freezing and Thawing Resistance of Cement Mortar for Precast Products)

  • 한천구;신병철;김기철;이상태
    • 콘크리트학회논문집
    • /
    • 제12권3호
    • /
    • pp.11-19
    • /
    • 2000
  • It has been reported that few manufacturers of cement mortar for precast products use chemical and mineral admixture due to the absense of restrictions related to the application of admixture and the poor manufacturing facilities. Therefore, this paper is intended to contribute to the improvement of quality by investigating the properties of cement mortar for precast products using fly ash, blast furnace slag and AE water reducing agent. According to the test results. it was found that the cement mortar products using fly ash and AE water-reducing agent had better qualities than those of ordinary portland cement.

황산염에 노출된 구조용 합성섬유와 라텍스 개질 시멘트 모르타르의 부착특성에 미치는 광물질 혼화재의 효과 (Effect of Mineral Admixture on Bond between Structural Synthetic Fiber and Latex Modified Cement Mortar under Sulfate Environments)

  • 김동현;이정우;박찬기
    • 한국농공학회논문집
    • /
    • 제54권5호
    • /
    • pp.25-34
    • /
    • 2012
  • It has been well known that concrete structures exposed to acid and sulfate environments such as sewer etc. show significant decrease in their durability due to chemical attack. Such deleterious acid and sulfate attacks lead to expansion and cracking in concrete, and thus, eventually result in damage to cement mortar by forming expansive hydration products due to the reaction between cement hydration products and acid and sulfate ions. In this study, the effect of fly ash and blast furnace slag on the bond performances of structural synthetic fiber in latex modified cement mortar under sulfate environments. Fly ash and blast furnace slag contents ranging from 0 % to 20 % are used in the mix proportions. The latex modified cement mortar specimens were immersed in fresh water, 8 % sodium sulfate ($Na_2SO_4$) solutions for 28 and 50 days, respectively. Pullout tests are conducted to measure the bond performance of structural synthetic fiber from latex modified cement mortar after sulfate environments exposure. Test results are found that the incorporation of fly ash and blast furnace slag can effectively enhance the PVA fiber-latex modified cement mortar interfacial bond properties (bond behavior, bond strength and interface toughness) after sulfate environments exposure. The microstructural observation confirms the findings on the interface bond mechanism drawn from the fiber pullout test results under sulfate environments.

고로슬래그를 사용한 건식 및 습식 재생 잔골재 모르타르의 물리적 특성에 관한 연구 (A Study on the Physical Properties of Recycled Fine Aggregate (by Dry and Wet Type Production formula) Mortar Using Blast Furnace Slag)

  • 심종우;이세현;서치호
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2006년도 추계 학술발표회 논문집
    • /
    • pp.501-504
    • /
    • 2006
  • Recycled aggregate mortar contains plenty of calcium hydroxide to improve the strength of blast furnace slag, although the surface mortar made of recycled aggregate deteriorates adhesion to cement paste and blast furnace slag has a low initial strength. Therefore, this study assumes that the combination with both recycled aggregate and blast furnace slag will produce a better performance. The results of the experiment show that dry mortar made of recycled aggregate provides with higher strength than wet mortar does at the 3-day and 7-day age, while lower at the 28-day age. It indicates that a large amount of cement mortar made of dry recycled aggregate has deteriorated adhesion strength. The mixes with 30% and 50% of blast furnace slag and 50% and 75% of recycled aggregate provide with much better strength at the 7-day age, although they usually have latent hydraulic property at the 28-day age. It indicates that calcium hydroxide($Ca(OH){_2}$) in recycled aggregate has affected ground granulated blast furnace slag.

  • PDF

분말형 자극제를 이용한 고로슬래그미분말 혼입 시멘트 모르타르의 조기 압축강도 향상에 관한 실험적 연구 (An Experimental Study on the Early Compressive Strength Improvement of Cement Mortar Mixed with Blast Furnace Slag using Powdered Stimulants)

  • 이강진;김진형;박기봉;이한승
    • KIEAE Journal
    • /
    • 제12권3호
    • /
    • pp.115-122
    • /
    • 2012
  • Based on previous research and existing literature, this study examines the development of admixture, which increases the early concrete strength (1 and 3 day) by mixing blast furnace slag cement and concrete stimulant. The research on early strength development of concrete is necessary in dealing with the drawbacks of slow early strength concrete on site and to shorten the construction time. The study confirmed that when a high alkaline mortar mixture is mixed with blast furnace slag, the early strength of admixture exceeds that of ordinary portland cement (OPC). The use of calcium chloride ($CaCl_2$) promotes hydration of cement at low temperature and show similar strength as the blast furnace slag admixture. Although calcium chloride seems economically advantageous, it causes steel corrosion and its use in concrete should be further studied in-depth.

고로슬래그의 분말도 신속평가 및 분말도가 시멘트 모르타르의 특성에 미치는 영향 (Rapid Evaluation Method for Blast Furnace Slag Fineness and Influence of Fineness on Properties of Cement Mortar)

  • 한천구;주은희
    • 대한건축학회논문집:구조계
    • /
    • 제34권5호
    • /
    • pp.13-18
    • /
    • 2018
  • In this research, regarding the type three blast furnace slag (BS) regulated by KS F 2563 and supplied to actual ready mixed concrete plant, the fineness on specification and actually measured fineness by Blain test were compared, and by applying the hydrometer method used for early prediction of concrete strength, the feasibility of the hydrometer method for acquisition inspection of BS was analyzed. Additionally, the influence of various fineness of BS on properties of cement mortar was also assessed. According to the experimental results of this research, correlation of fineness values between specification and actually measured data were not matched. In the case of the rapid evaluation method using hydrometer, a good relation was shown between the fineness data obtained from hydrometer and Blain test. furthermore, from the cement mortar properties test, there was a good relation was obtained between fineness data from rapid evaluation method by hydrometer and cement mortar properties, while there was no clear relation between fineness data from specification and cement mortar properties. Hence, as a qulity controlling method of BS fineness, a rapid evaluation method using hydrometer is suggested as a new method.