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        검색결과 77

        21.
        2017.04 서비스 종료(열람 제한)
        In this study, it was developed geopolymer concrete of alkali-activated using the mixed fly ash and blast furnace slag. and it was developed the interlocking block using the developed geopolymer concrete. In addition, the bending strength and water absorption rate of the interlocking block was tested by KS standard. The test results were as follows. The water adsorption ratio of the BSF4 specimen was under 10%, and the flexural strength of that was over 5MPa
        22.
        2017.04 서비스 종료(열람 제한)
        The effect of loading on chloride penetration into concrete is evaluated in this study. It is found that the chloride pene- tration rates for OPC concrete and blast furnace slag BFS concrete under the tensile stress were increased by 29% and 77%, respectively. The diffusion coefficient of FA and BFS concrete was lower than that of conventional concrete without BFS, no loads and stress states. Under tensile stress, the diffusion coefficient for FA and BFS, plain concrete showed higher values with increasing stress. The influence of specific surface area on the diffusion coefficient was investigated. As a result, the larger the specific surface areas of BFS are the lower diffusion coefficients. This tendency was more pronounced under the high stress conditions. The chloride penetration depth was distributed uni- formly when no stress was applied. However, in the case of tensile loading, the diffusion depth was not distributed uni- formly, and showed prominent characteristics. This result indicates that analysis using average values of chloride pene- tration depth is not proper under load conditions.
        23.
        2017.01 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study was to evaluate flowability of engineered cemetitious composite(ECC) Using blast furnace slag and fly ash as a binder in mixture. From the test result, flowability value of all ECC mixtures show good flowability and self compacting performance.
        24.
        2017.01 KCI 등재 서비스 종료(열람 제한)
        In general, polymer cement mortars that is made from organic polymer dispersion and cement have good workability compared with ordinary cement due to ball-bearing acting of polymer particles in cement mortar. The purpose of this study is to evaluate the workability of cement mortar according to adding of admixtures such as polymer dispersions, blast-furnace slag and fly ash. From the test results, the flow of polymer-modified mortars is increased with increasing polymer-cement ratio, and also is a little improved according to adding of fly ash compared to blast-furnace slag.
        25.
        2017.01 KCI 등재 서비스 종료(열람 제한)
        In this study, it was developed geopolymer concrete of alkali-activated using the mixed fly ash and blast furnace slag. and it was developed the interlocking block using the developed geopolymer concrete. In addition, the bending strength and water absorption rate of the interlocking block was tested by KS standard. The test results were as follows. The water adsorption ratio of the BSF4 specimen was under 10%, and the flexural strength of that was over 5MPa.
        26.
        2016.10 서비스 종료(열람 제한)
        The purpose of the present study is to investigate some effects of concrete according to addition of blast furnace slag and sulfuric alkali-activator. Blast furnace slag was used at 30~80% replacement by weight of cement, and liquid sulfur having NaOH additives was chosen as the alkaline activator. In order to evaluate characteristics of blast furnace slag concrete with sulfuric alkali activators, compressive strength test, carbonation test were performed.
        27.
        2016.09 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 경량기포 콘크리트를 이용한 육성용 토양골재의 적용성을 평가하기 위해서 고로슬래그 기반 기포콘크리트의 총 8 배합과 인공토양골재를 제조하였다. 고로슬래그 기반 기포콘크리트 배합의 주요변수는 단위결합재량으로서 100에서 800 kg/m3으로 변화하 였다. 경량기포콘크리트는 플로우, 슬러리 및 절건 밀도와 재령별 압축강도를 측정하였으며, 파쇄된 인공토양골재는 pH, 입도분포, 투수계수, 양이온치환용량(CEC), 유기물함유량(C/N비)을 측정하였다. 측정결과 경량기포콘크리트의 플로우, 슬러리 및 절건밀도와 재령별 압축강도는 단위결합재량이 증가함에 따라 증가하였다. 경량기포콘크리트의 단위결합재량이 500 kg/m3 이상인 배합의 28일 압축강도는 4 MPa 이상이었 다. 인공토양골재에 3일 이상의 15% 희석된 제1인산암모늄의 수용액침지는 pH를 저감시키는데 효과적이었다. 또한 제조된 인공토양골재는 양이온 치환용량(CEC) 측면에서 상급으로 평가되었지만 C/N비 측면에서는 조경시방서를 만족시키지 못하였다.
        28.
        2016.04 서비스 종료(열람 제한)
        Even though high performance concrete was developed according to becoming bigger and higher of reinforced concrete building, the rheological evaluation is not enough to use as input data to accomplish the numerical analysis of construction design. Consistency curves were measured by the viscometer as hydration reaction time passed. There are a sudden change of viscosity and yield stress around initial setting in case of low W/B. The increase of workability by the change of free water in cement paste was offset by the coating effect of impermeable layer in case of W/B 40%.
        29.
        2016.04 서비스 종료(열람 제한)
        This study evaluates the material performance of slump value and compressive strength of the concrete which was made by recycled sand and blast furnace slag powder(BFSP). The main variables are replacement ratio of BFSP. As a result, it was evaluated that more detailed evaluation is needed in long-term strength development and the compensation of slump value to the replacement ratio of BFSP.
        30.
        2015.10 서비스 종료(열람 제한)
        The study is compressive strength of 110MPa PHC pile using ground granulated blast furnace slag to NAC, AC curing method. In the result, 20% of ground granulated blast furnace slag could be substituted for cement in PHC pile concrete.
        31.
        2015.10 서비스 종료(열람 제한)
        In experimental results, the prediction equation for 28 day-strength of GGBF slag concrete could be produced through the linear regression analysis of early strength and 28 day-strength. In order to acquire the reliability, all mixture were repeated as 3 times and each mixture order was carried out by random sampling. The prediction equation for 28 day-strength of GGBF slag concrete by 1 day strength won the good reliability.
        32.
        2015.09 KCI 등재 서비스 종료(열람 제한)
        본 연구는 혼합 활성화제에 의한 알칼리 활성화 슬래그 시멘트(AASC)의 역학적 특성에 관한 연구이다. 사용된 활성화제는 황산칼슘(CaSO4, 이하 CS), 황산나트륨(Na2SO4, 이하 SS) 및 수산화나트륨(NaOH)이다. 황산염은 슬래그 중량의 2.5, 5.0, 7.5 및 10.0%로 치환하여 사용하였으며, NaOH는 2M 및 4M 농도의 수용액으로 사용하였다. 본 연구에서는 황산염(CS 및 SS) 치환율에 따른 배합(4가지 배합)과 2M 및 4M의 각각의 NaOH 수용액에 치환된 황산염을 혼합하여 시험체를 제작하였다. 시험체는 총 24가지의 배합에 따라 페이스트로 제작되었으며, 물-결합재 비는 0.5로 하였다. 경화된 시험체에 대해서 압축강도, 휨강도, 초음파속도(UPV), 흡수율 및 XRD 분석을 수행하였다. CS의 활성화제를 사용한 경우는 7.5% CS 치환율, 2M NaOH 수용액+ 5.0% CS 치환율 및 4M NaOH 수용액+ 5.0% CS 치환율의 시험체에서 최고의 압축강도를 나타내었다. 또한, SS의 활성화제를 사용한 경우는 10.0% SS 치환율, 2M NaOH + 7.5% SS 치환율 및 4M NaOH + 2.5% SS 치환율에서 최고의 압축강도 발현을 나타내었다. 휨강도, UPV 및 흡수율은 압축강도 발현 결과와 유사한 경향을 나타내는 것을 알 수 있었으며, XRD 분석결과 시험체 내에 생성된 반응물질은 ettringite, CSH 및 실리케이트계 수화물인 것으로 나타났다. AASC에서 황산염과 NaOH의 혼합 사용은 황산염의 단독 사용의 경우와 비교하여 일정 수준의 농도 범위에서 강도를 향상시키고 조직을 치밀화 시키는 등의 긍정적인 영향을 미치는 것으로 판단된다.
        33.
        2015.05 서비스 종료(열람 제한)
        Method for Protect of the river levee was method for installing concrete revetment block and concrete mat method in Korea. But this method is non-environmental approach because the vegetation can not take at all. To solve these problem, the method has been applied using porous vegetation concretes. Porous vegetation concrete has filler technique to provide water retention and nutrient a into the porous interior in order to facilitate plant growth. But filler used increasing the cost and the construction period. Therefore in order to not use a filler, a high absorption rate and good absorption capacity needed aggregate. Current, Blast furnace slag aggregate has been used in architectural and civil engineering field as an alternative aggregate resources. Blast furnace slag aggregate is high absorption rate and lighter in weight per unit. This study evaluated the absorption capacity of the blast furnace slag aggregate. Phosphorus Sorption experiment was carried out to produce a cylindrical acrylic(diameter 11cm, height 90cm). There filling the aggregate, for supplying the test solution was using as a pump from bottom to top. And The water of having passed through the solution was analyzed. Results, blast furnace slag aggregate showed absorption capacity of 64~77% of PO43-P and T-P. Crushed aggregate show absorption capacity of 6~24% of PO43-P and T-P. Blast furnace slag aggregate showed excellent result of good absorption capacity compared to the crushed aggregate showed excellent result.
        34.
        2015.04 서비스 종료(열람 제한)
        This research investigated the effects of adding ground granulated blast furnace slag (GGBS) on the pullout resistance of smooth steel fibers embedded in GGBS cement grouts. 40% of cement in the grouts was replaced with GGBS to enhance the flowability and durability of grouts containing steel fibers. The pullout resistance of steel fibers embedded in grouts showed continuous enhancement as the age of grouts increased. The pullout resistance of GGBS grouts was higher than that of grouts without GGBS.
        35.
        2015.04 서비스 종료(열람 제한)
        In experimental results, the prediction equation for 28 day-strength of GGBF slag concrete could be produced through the linear regression analysis of early strength and 28 day-strength. In order to acquire the reliability, all mixture were repeated as 3 times and each mixture order was carried out by random sampling. The prediction equation for 28 day-strength of GGBF slag concrete by 1-day strength won the good reliability.
        36.
        2015.04 서비스 종료(열람 제한)
        Concrete with blast furnace slag (BFS) shows varied strength development properties different from normal concrete. Therefore, a precise prediction of compressive strength using a full maturity model is desired. The purpose of this study is to predict the compressive strength of concrete with BFS by calculating the apparent activation energy (Ea) and rate constant (kT) for each BFS replacement ratio. The method of Carino Model is used in this study for predicting compressive strength of concrete with BFS.
        37.
        2015.04 서비스 종료(열람 제한)
        As a result of strength test on FA and BFS, FA concrete showed higher increase of strength compared to OPC, when FA4000 and FA5000 were mixed 30%, respectively. For BFS concrete, those mixed with 30% and 50% of BFS8000, respectively, showed higher or equivalent strength compare to OPC. As a result of test of chloride penetration on FA and BFS, diffusion coefficients of concrete mixed with 30% FA4000 and FA5000, respectively, showed to restrain average 6.5% of diffusion coefficient compared to OPC. And in case of BFS concrete, those mixed with BFS6000 and BFS8000, restrained diffusion of chloride ions 253% and 336%, respectively, compared to OPC. Therefore, Mixing 50% of BFS was most efficient in order to maximize restraint of chloride penetration according to metathesis of large amount.
        38.
        2015.04 서비스 종료(열람 제한)
        The study on physical properties of PHC pile and pile filler using blast furnace slag were evaluated. In the results, it was found that compressive strength and workability of PHC pile concrete with 20% of blast furnace slag adjusted S/a 27% were satisfied with desired properties and it was available to improve flow and compressive strength of file filler with 35% of blast furnace slag and TG as additive.
        39.
        2015.04 서비스 종료(열람 제한)
        Concrete with blast furnace slag (BFS) shows varied strength development properties different from normal concrete. Therefore, a precise prediction of compressive strength using a full maturity model is desired. The purpose of this study is to predict the compressive strength of concrete with BFS by calculating the apparent activation energy (Ea) and rate constant (kT) for each BFS replacement ratio. The method of Carino Model is used in this study for predicting compressive strength of concrete with BFS.
        40.
        2015.03 KCI 등재 서비스 종료(열람 제한)
        CO2 emitted from building materials and construction materials industry reaches about 67 million tons, which occupy about 30% of CO2 emitted from the construction field. Controls on the use of consumed fossil fuels and reduction of emission gases are essential for the reduction of CO2 in the construction area as we reduce the second and third curing to emit CO2 in the construction materials industry. Accordingly, this study applied the low energy curing admixture (hereinafter “LA”) to the extruded panels to observe the physical properties, depending on the mixing amount of fiber, type of fiber and mixing ratio of fiber. The type of fiber did not appear to be a main factor to affect strength, while the LA mixing ratio and mixing amount of fiber appeared to be major factors to affect strength. Especially, the highest strength was developed when the LA mixing ratio was 40%, whereas the test object with the mixing ratio of 50% resulted in the decrease of strength. In addition, it appeared that the mixing ratio of fiber greatly affected flexural strength and strength increased as the mixing ratio increased.
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