• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.42-43
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• 2018

The research is to suggest the compensating strength values depending on various managing periods of concrete based on the strength development model calculated with equivalent age method for 20% of blast furnace slag replaced concrete. As a result, for 28 days of managing period, 9, 6, and 3MPa of compensating strength values were suggested when the temperatures were from 4 to 6℃, from 6 to 12℃, from 12 to 17℃, respectively. Additionally, for 42 days of managing period, 6 and 3MPa of compensating strength value was suggested when the temperature was from 4 to 7℃, from 7 to 12℃, and for 56 days of managing period, 3MPa of compensating strength value was suggested when the temperature was from 4 to 9℃. Furthermore, for 28, 42, 56, and 91 days of managing periods, any compensating strength values were needed when the temperature were higher than 17, 12, 9, and 4℃, respectively.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.3
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• pp.253-260
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• 2017

The aim of research is to investigate various physical properties of ultra high strength concrete of 80MPa class using a combination of limestone aggregate and electronic arc furnace oxidizing slag aggregate. For aggregate combinations, granite and limestone are used for coarse aggregate, granite and limestone are also used for fine aggregate. And also, limestone fine aggregate is replaced by electronic arc furnace oxidizing slag aggregate of 25% and 50%. Test results indicated that flowability and compressive strength increased when limestone fine aggregate was used compared to that using granite fine aggregate due to higher modulus of elasticity by limestone. Also substitution of electronic arc furnace oxidizing slag aggregate resulted in a decrease of compressive strength slightly. It is found that the use of electronic arc furnace oxidizing slag aggregate and limestone aggregate would be favorable for reducing the autogenous shrinkage by as much as 9~25%.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.2
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• pp.41-49
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• 2020

To improve the problem of strength reduction of unary and binary blended non-cement concrete that occur at room temperature, comparative analysis was conducted based on the slump and compressive strength properties of ternary blended non-cement concrete in which cement was replaced with silica fume, fly ash, and blast furnace slag, and the following conclusions were drawn. The ternary blended non-cement concrete showed higher compressive strength than binary binder concrete, and the slump reduction was less when 10% silica fume was mixed. In addition, the appropriate composition ratio range of each by-product was suggested according to slump and compressive strength level based on ternary diagram.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.1
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• pp.103-110
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• 2010

Recently, reducing usage of cement and using by-product of industry such as blast furnace slag and fly-ash have been increased to reduce $CO_2$ gas emission. That apply to construction. As a result, reduction of environmental stress and recycling of resources are expected. In this study, as basic study to the reuse of resources and reduce Environmental Load, comparing and analyzing hardening characteristics and durability as using the blast furnace slag and fly-ash, examining concrete characteristics substituted the three elements for the blast furnace slag and fly-ash and evaluating the relationship as binder. Through this, it want to provide the basic data for mass utilization. Blast furnace slag powder and replaced at fly-ash compressive strength of concrete in the strength of the initial seven days material age lower level of expression significantly compared to the concrete, but, 28 days after the similar or higher compressive strength than the concrete expression of the was. In addition, the reserves replacement of blast furnace slag powder salt injury increasing resistance are seen improvements, according to the conventional blast furnace slag powder study by the chloride ions on the surface of the concrete are improved being fixation salt injury resistance is considered.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.389-392
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• 2008

Electric-furnace-slag has the expansion, due to the reaction with water and free Cao. So compared with the blast-furnace-slag, the recycling range of EFS is subject to restriction. But the expansive reaction of EFS is removed, the it is possible to use aggregate for concrete. This study is the basic properties of concrete to used stabilized EFS(oxidized EFS). The EFS is used fine aggregate in concrete, and replaced by sea-sand(natural sand). The replacement ratio are 0%, 25%, 50%, 75%, 100%. The result of study, to used oxidized EFS-sand, the flowability and the compressive strength is increased. Also it is possible to reduce the Bleeding. It is necessary more study about using the EFS aggregate, like the durability, the mechanical property for concrete

• Resources Recycling
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• v.19 no.1
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• pp.13-20
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• 2010

Much energy is consumed up when making a concrete. And especially, because lots of $CO_2$ is discharged for combination material, cement, we are making efforts in order to get lid of this negative thought. Recently, much interest is given to manufacturing eco concrete which is environment friendly and its' application. We should study manufacturing of the concrete whose environment friendly performance should be improved as consistent development concept in order for various approaches to be settled down our country such as lowering of environmental load, utilization of industry wastes and improvement of environment related performance. This study inquired into utilization possibility through from various tests results after manufacturing eco type mixed concrete whose purpose is to lower environmental load in which cement and aggregates can be replaced with metakaolin which is natural material and copper slag which is industry by product.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.244-245
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• 2014

This is an experimental study on manufacturing of non-cement matrix. Materials like cement and blowing agent in foamed concrete is replaced by by-products from blast furnace slag and paper ash. Further, the experiment was performed by replacing alkali with red mud by (0, 5, 10, 15, 25, 35, 45) of weight of alkali (wt.%) in order to reduce the amount of expensive alkali acclerator. Sample Plain with density showed lowest. The compressive strength test result, showed a similar trend with density. And it showed that compressive strength of the RM-0.05 was highest.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.116-117
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• 2018

The aim of this study is to investigate the properties of hardened mortar with chlorine by-pass system(CBS) in cement production in blast furnace slag(BS) mixed cement. Compressive strength had a tendency to be increased when the CBS Dust was replaced by 10% at the BS replacement rate of 0%. The 65% combination of BS showed a tendency to decrease as the CBS Dust exchange rate increases. Flexural strength was reduced as CBS Dust exchange rate increases in BS replacement ratio of 0%. The use of 5% of CBS dust can contribute to enhance the quality of non reinforced concrete.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.3 s.55
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• pp.93-100
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• 2009

This study forms part of a research project that was carried out on the development and application of high-strength concrete for large underground spaces. In order to develop 50MPa high-strength concrete, eight optimal mixtures with different portions of fly ash and ground granulated blast furnace slag were selected. For assessments of shrinkage characteristics, free shrinkage tests with prismatic specimens and shrinkage crack tests were performed. The compressive strength was more than 30MPa at 7days, and stable design strength was acquired at 28days. High-strength concrete containing blast furnace slag shows large autogenous shrinkage, while large shrinkage deformations and cracks will occur when mixtures are replaced with large volumes of cementitious materials. Hence, for these high-strength concrete mixtures, the curing conditions of initial ages that affect the reaction of hydration and drying effects need to be checked.

• Journal of the Korea Institute of Building Construction
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• v.15 no.6
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• pp.597-605
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• 2015

The method of concrete mix design used in this study aims to achieve the identical specified design strength, applying different types and replacement ratio of mineral admixtures and afterwards, fire tests were conducted using the standard time-temperature curve specified in the ASTM E119 to identify the influences of the types of mineral admixtures on the fire resistance performance of high strength concrete(HSC). The least spalling was observed in the test specimen containing blast furnace slag as a partial replacement of cement, while the most significant spalling phenomena were observed in the blast furnace slag test specimen that silica-fume was added in. In particular, the reasonable volume of spalling was observed when solely replaced by silica fume. However, the influence of the cement replacement by silica fume and blast furnace slag on the increases of spalling can be explained through blocked pores by the fine particles of silica fume, leading to decreases in permeability.