• Journal of the Korea Institute of Building Construction
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• v.14 no.1
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• pp.37-44
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• 2014

Recently, many efforts related to the utilization of industrial by-products have been made to reduce carbon dioxide emissions in the construction industry. Of these various efforts, concrete incorporating ground granulated blast furnace slag (BFS) provides many advantages compared to conventional concrete, such as high long-term compressive strength, improved durability and economic benefits because of its latent hydraulic property, and low compressive strength at early curing age. This paper investigates the compressive strength of high-activated ground granulated blast furnace slag blended mortar with slag by-product S type(SBP-S). The results of the experiment revealed that incorporating high-activated ground granulated blast furnace slag would affect the compressive strength of mortar. It was found that increasing the Blaine fineness and replacement ratio of slag by-product S type shows high compressive strength of mortar at early curing age because of its high $SiO_2$ and CaO contents in the slag. It is confirmed that an increase of curing age does not affect the compressive strength of mortar made with slag by-product S type at a high curing temperature. Moreover, it is possible to develop and design concrete manufactured with high-activated ground granulated blast furnace slag as binder considering the acceleration curing conditions and mix proportions.

• KSTLE International Journal
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• v.2 no.2
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• pp.133-137
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• 2001

This paper investigates the correlation between strip surface roughness and the surface of the work roll. As the actual temper mill(TM) is used, this data will be adopted to another actual temper mill for the application and operation of this experiment. Conclusions are as follows: Electro-discharge texturing(EDT) roll has homogeneous roughness distribution and shape, and also a sinuous peak surface and the life is 2 times longer than that of shot blast texturing(SBT) method. And the higher surface roughness of work roll, the more time is necessary at the EDT method. In the SBT method without the correlation of roughness, but impeller rotation speed with an uncontrollable peak count. The roughness of SBT roll is irregularity compared to that of EDT roll because the work roll roughness is transferred to the strip which was temper rolled, and produces a more desirable image and greater clarity to the color painted steel sheet.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.313-318
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• 2001

The cost of producing ready mixed concrete(remicon) has increased due to the rising cost of raw materials for concrete and transportation caused by the upturn of oil price. In contrast, its orders have also decreased due to the recession of the construction industry. In addition, the cost of delivery has decreased owing to the excessive competition among manufacturing companies, so manufacturing companies began mixing ground granulated blast-furnace slag or fly ash to lower the cost. However, there is no way to determine whether the strength of the concrete using the admixture is satisfied or dissatisfied with design strength at the early age. The purpose of this study is dedicated to early strength estimation of concrete mixed with an admixture, ground granulated blast-furnace slag.

• Tunnel and Underground Space
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• v.3 no.1
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• pp.54-62
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• 1993

In order to evaluate the necessity for the support during the excavation of the transport drift and use the data for design applications, laboratory testings of mechanical properties of rock samples and engineering rock mass classifications on this study site were performed. The values of RMR and Q-system are 68 and 11.8, respectively. Since these results were evaluated as good, this rock mass were determined to be unsupported. Full face excavation method was determined to be suitable for excavating this drift. In case of excavation, smooth blasting techniques must be carried out at the wall rock and the crown. However, considering the blast vibration etc. that have an effect on the surrounding rock mass, approximately less than 9kg of explosive charges per blast should be maintained.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.584-587
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• 2004

This research investigates the rheological behavior and the confined water ratio of the cement paste and binder condition in order to predict mix design proportion of the high flowing concrete. The purpose of this study is to determine the optimum replacement ratio of binders including fly ash, and lime stone powder by the cement weight. For this purpose, belite cement, blast furnace slag cement and ordinary portland cement are selected. As test results, the confined water ratio shows the following range ; OPC>blast furnace slag cement>belite cement. Therefore, belite cement is proved very excellent cementitious materials in a view point of the flowability. The optimum replacement ratio of lime stone powder is shown over $30\%$ in case of belite cement and about $10\%$ in case of slag cement type. Also, the optimum replacement ratio of fly ash is shown $30\%$ by the cement weight considering the confined water ratio and deformable coefficient of the paste condition.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.149-152
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• 2002

This study is performed to evaluate the properties of ECO-permeable polymer concrete with blast furnace slag powder and stone dust. The unit weight is in the range of $1,821kg/m^3{\sim}1,955kg/m^3$, the unit weights of those concrete are decreased $15%{\sim}20.8%$ than that of the normal cement concrete. The highest strength is achieved by ECO-permeable polymer concrete filled blast furnace slag powder 50% and stone dust 50%, it is increased 36% by compressive strength, 119% by tensile strength and 217% by bending strength than that of the normal cement concrete, respectively. The coefficient of permeability is in the range of $5.6{\times}10^{-2}cm/s{\sim}8.1{\times}10^{-2}cm/s$, and it is largely dependent upon the mix design.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.625-630
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• 1999

This study was carried out to investigate quantitatively the relatonship between the water binder ratio and the concrete strength using finely ground granulated furnace blast slag to apply f 0.5% type admixture. The experimental parameters are water-binder ratio (40, 45, 50, 55, 60%) and slag contents(0, 10, 20, 30%). As a result, it can make that the water-binder ratio of concrete contented slag can be calculated by equation using relationship between compressive strength of concrete and water-binder ratio which is consisted of mixing strength and cement strength K.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.13-16
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• 2006

This paper investigates the shrinkage behavior of Ultra High Strength(UHSC) having three water-to-cementitious material ratio, 0.20, 0.16, 0.12. All of mixtures have same design compressive strength. Free shrinkage test for autogenous and drying shrinkage using $100{\times}100{\times}400$ prismatic specimen was conducted. On all mixture, Effects of fly ash and blast-furnace slag on each shrinkage test results were also investigated. The largest portion of autogenous shrinkage was observed in UHSC12 (w/b=0.12) and the measured strain was as high as 80% of the total drying shrinkage strain. The autogenous shrinkage of UHSC decreased as the amount of fly ash increased as demonstrated in the literature. However, the results of the effect of blast-furnace slag on autogenous shrinkage were somewhat different from previous researches.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.53-56
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• 2006

To develop more durable concrete deck, performance characteristic test of HPC(High Performance Concrete) mixtures was carried out. The parameters used in this project were ; the mineral admixture details were 4 types such as ordinary portland cement(OPC), 20% fly ash (FA), 20% fly ash and 4% silica fume(FS), and 40% ground granulated blast-furnace slag(BS). Their design compressive strengths were 27MPa and 35MPa respectively. The results showed the compressive strength of concrete did not much affect the durability of concrete. HPC with blast-furnace slag(BS) showed the good durability but was prone to crack. HPC with fly ash(FA) or with fly ash and silica fume(FS) had the good durability and crack resistance.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.144-149
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• 2000

Porous cement concrete was developed to prevent hydroplaning of airway pavement or to reduce noise emission in highway. In has been introduced in domestic since early 1980' and applied to a pedestrian road or bike way. The concrete, however, has problems such as lack of optimized mix design, low strength and deterioration, etc. The purpose of this study is to manufacture porous cement concrete using blast-furnace slag to enhance mechanical properties. The results of this study are as follows; the compressive strength range is 102∼247kgf/㎠, the tensile strength range is 16∼70kgf/㎠, the bending strength range is 43∼70kgf/㎠, and the coefficient permeability range is 6.79 ×10-2∼1.17∼10-1cm/sec. To develope high-performance porous concrete, further studies are needed on optimum mixture of fineness modulus and admixture.