• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.137-138
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• 2013

Nowadays, research about using recycled aggregate as alkali activator has been investigated. By the mechanism of Alkali activation, blast furnace slag's potential hydraulis property would be activated. Thee application of this technique is considered as fit for low strength concrete, so it's suitable in concrete secondary production such as bricks and blocks. Aside alkali activator, sulfate could also activate blast furnace slag's potential hydranlis property. In this research, gypsum(CaSO4·2H2O)has been added with blast furnace slag. Fundamental experiment such as flow and strength has been tested to evalnate effect of gypsum's activation property.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.207-208
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• 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.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.1
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• pp.9-14
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• 2022

Most of the existing research on ferronickel slag has focused on its potential as aggregate and fine aggregate, this study was conducted focusing on the potential of ferronickel slag powder as a concrete admixture. For concrete, which fly ash, blast furnace slag, and FSP were mixed with each 10 % type the reactivity was evaluated by applying ASTM C 1260 of the United States. As a result, compared with the control group, the expansion rate of fly ash decreased by 8.43 % and that of fine blast furnace slag powder decreased by 14.46 %, while the expansion rate of ferronickel slag decreased by 49.40 %. it was confirmed that ferronickel slag can sufficiently be replaced existing supplementary cementitious admixtures such as fly ash and blast furnace slag in terms of suppressing the reactivity of aggregates. However as a result of SEM analysis, ettringites were generated, and additional research about how it affects concrete is needed.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.7
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• pp.47-53
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• 2004

Permeable polymer concrete can be applied to roads, sidewalks, river embankments, drain pipes, conduits, retaining walls, yards, parking lots, plazas, interlocking blocks, etc. This study was to explore a possibility of using blast furnace slag powder and stone dust of industrial by-products as fillers for Eco-permeable polymer concrete. Different mix proportions were tried to find an optimum mix proportion of the Eco­permeable polymer concrete. The tests were carried out at $20{\pm}1^{circ}C$ and $60{\pm}2\%$ relative humidity. At 7 days of curing, unit weight, coefficient of permeability, dynamic modulus of elasticity, compressive, flexural and splitting tensile strengths ranged between $1,821{\~}1,955 kg/m^{3}$, $0.056{\~}0.081\;cm/s$, $114{\times}0^{2}{\~}157{\times}10^{2}\;MPa,\;17.6{\~}24.7\;MPa,\;5.98{\~}7.94\;MPa\;and\;3.43{\~}4.70\;MPa$, respectively. It was concluded that the blast furnace slag powder and stone dust can be used in the Eco-permeable polymer concrete.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.33 no.12
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• pp.63-70
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• 2017

When industrial by-products like slag and fly ash are using in concrete with cement, it improves strength and durability against external deterioration factors by densifying the structure through potential hydraulic and pozzolanic reaction. But it has been pointed out that high dependence on the quality variation and the curing condition using a admixure material for concrete. In this study, the characteristics of internal micropore structure according to curing condition were analyzed for pastes and mortar specimens under using blast furnace slag powder. As a result, the variation of compressive strength and the internal microstructure were observed according to curing conditions by binder type. Particularly, using blast furnace slag powder, decrease in compressive strength were clearly observed in indoor and carbonation curing compared with water curing. The pore structure analysis also clearly observed the decrease of the gel pore existing in the CSH hydrate layer and the increase of the capillary pore in indoor and carbonation curing compared with water curing condition.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.272-277
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• 2000

This study is performed to evaluate the engineering properties of permeable polymer concrete with blast furnace slag and fly ash. The following conclusions are drawn; 1. The highest strength is achieved by 50% filled blast furnace slag powder and fly ash permeable polymer concrete, it is increased 36% by compressive strength, 119% by tensile strength and 217% by bending strength than that of the normal cement concrete, respectively. 2. The ultrasonic pulse velocity is in the range of 2,022 ∼ 2,139m/s. The highest pulse velocity is showed by 50% filled blast furnace slag powder and fly ash permeable polymer concrete. 3. The water permeability is in the range of 4.612∼5.913$\ell$/$\textrm{cm}^2$/h, and it is largely dependent upon the mix design.

• Journal of the Korea Institute of Building Construction
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• v.17 no.6
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• pp.527-534
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• 2017

Accordingly, this study, in order to use powder of recycled aggregate from production of recycled aggregate as an activator of ground granulated blast furnace slag, the influence of added recycled aggregate powder on physical properties of concrete induced ground granulated blast furnace slag were analyzed by hydration stages. The results of the study are summarized as follows: Except for samples eluted powder of recycled aggregate 1%, all the samples were high alkali suspensions with higher than pH 12.0. In particular, when eluted time was 5 hours, the sample eluted powder of recycled aggregate 3% showed about 15 mg/l of calcium hydroxide that was not different from the amount of calcium hydroxide in the mixing water eluted powder of recycled aggregate 5%. Hence, from this results, it can be considered that optimal eluted powder of recycled aggregate was 3% in this study. When using mixing water eluted with powder of recycled aggregate, compared to use of ordinary mixing water, it showed greater compressive strength in the entire ages, and in the sample replaced with ground granulated blast furnace slag by 50%, its compressive strength was greater than that of the OPC. As use of mixing water eluted with powder of recycled aggregate in concrete used with large amount of ground granulated blast furnace slag was more effective for improving compressive strength than ordinary mixing water, it is verified that powder of recycled aggregate had an effect of activator.

• Journal of the Korea Institute of Building Construction
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• v.15 no.3
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• pp.257-263
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• 2015

In this study, the quality of blast furnace slag and the engineering properties of recycled aggregate based mortar with variable replacement of blast furnace slag have been focused. Blast furnace slag(BS) manufactured in various areas in Korea were prepared for this study. For the investigation results, 4 types(among the all of 9 types) of the experimental results were identified as below the standard level when using blast furnace slag chosen from different factories. Especially the particle size of the blast furnace slag was considered as the largest problem. When using BS in the recycled aggregates based mortar, the increase amount of blast furnace slag, increased the fluidity but delayed the setting time and decreased strength at early age. Based on the relationship of the amount of BS and the engineering properties of mortar, this study found that the amount of $SO_3$ and L.O.I affect the setting time, 3 days strength and 91 days strength to the certain standard level.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.217-218
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• 2011

The advantages of blast-furnace slag concrete may include lower hydration heating velocity, restraint on concrete temperature increase, long-age strength improvement due to latent hydraulic reaction, improved water tightness, and repulsion to chemical erosion. These advantages contribute to the high quality of the blast-furnace slag concrete. However, the blast-furnace slag concrete has its limitations as well. These disadvantages may include retarded setting and elongated retention of mold due to the weak strength of early-age. Nevertheless, much research is currently under way to improve the aforementioned issues. To improve activity of blast furnace slag powder, alkaline irritants has been used. In this study, we analyze effect on activity fineness and rate of substitution of Alkali Activator toward activity.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.128-134
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• 2005

This study was performed to evaluate the strength and durability properties of recycled concrete containing water - redispersible copolymer powder(WRP) and blast furnace slag powder(BSP) [RCWS]. Material used were cemente, recycled coarse aggregare, natural fine aggregate, water-redispersible copolymer powder, blast-furnace slag powder. Especially, Water-redispersible powder was used for blending with Inorganic binders such as cemente, gypsum and hydrated lime etc. First of all, Mixed ratio method of RCWS made Two Type. One was called type-1 which used to BSP content 5% and WRP(Water-redispersible powder) content 0%, 1%, 2%, 3%, 4%, 5%, 6%. respectively. Another was called Type-2 which used to BSP(blast furnace slag powder)content 10% and WRP(Water-redispersible powder) content 0%, 1%, 2%, 3%, 4%, 5%, 6%. respectively. According to the experimental results of (RCWS), Incase Type-2 at curing age 28days, Compressive strength, pulse velocity and dynamic modulous of elasticity were shown higher than Type-1 and The more WRP content increasing($0%{\sim}6%$) was the lower Compressive strength, Pulse velocity and Dynamic modulous of elasticity. Water absorption ratio was in the range of $3.85%\;{\sim}\;3.23%$, it was almost equal to Type-1, 2 but Increasing the WRP content($0%{\sim}6%$), The water absorption ratio is decreased.