• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.497-500
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• 2005

This study was performed to evaluate the characteristics which are slump, air content and time of set in fresh concrete and compressive strength of hardened concrete containing slag powder and fly-ash. Replacement rate of FA is fixed on 10$\%$ and replacement rate of slag powder are 0$\%$, 20$\%$ and 30$\%$. Also AE water-reducing agents(standard type, accelerating type) are used. The results were as follows. (1)Slump flow of concrete using AE water-reducing agents is similar. Flowability is incresed when replacement rate of slag powder is increased due to slag powder's ball bearing reaction.(2)Time of set of concrete using accelerating type agent is more faster than that of concrete using standard type agent because of ettringite generation that promote setting.(3)Early strength of three-component concrete using accelerating type agent is higher than that using standard type agent. Therefore cumulative pore is reduced due to ettringite

• 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.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.554-557
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• 2011

One of the issues that occurs in development of a combustor using Metal Powder as a fuel is an alumina slag processing. A water film formed inside the combustor is expected to be able to solve this issue. The experiments about the formation of a water film were carried out as a preliminary study. As the tangential velocity of water jet is increasing, the angle derivation from horizontal is decreasing for the test model. Results of the experiments showed that the thin water film on the inner surface appeared at the velocity of 10~15 m/s.

• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.139-140
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• 2016

In this research, the possibility of wasted refractory aggregate pulverized from refractory block as an expansive admixture and additional alkaline stimulant for class two and three blast furnace slag cements (BSC) was assessed with its high content of free CaO or free MgO. As the replacement ratios of wasted refractory powder and blast furnace slag were increased, flow and air content were decreased, while unit volume weight was increased under same conditions. Compressive strength of mortar was increased with increased replacement ratio of wasted refractory powder, especially, in the case of class three BSC, the highest compressive strength was obtained when wasted refractory aggregate was replaced 2%.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.05b
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• pp.77-80
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• 2009

The purpose of the study was to examine engineering characteristics due to fine particle cement and gypsum contents to improve early strength of concrete substituted blast furnace slag powder. The results were as follows. Above all, For fluidity, generally all mixtures had lower fluidity than Plain mixture and was not satisfied target scope, but for mixture substituted the gypsum showed a little increasing trend. For air content, generally all mixtures compared to Plain mixture had decreasing tendency. However, all mixtures were satisfied target scope. For compressive strength, long-term strength was better than early strength according to ternary blast furnace slag contents was increased. For complex mixture was better than individual use of gypsum and fine particle cement.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.164-165
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• 2019

Light-weight foamed concrete using cement as a raw material consumes a lot of energy and generates $CO_2$ because of the high temperature firing process in the manufacturing process of cement. This study was carried out to evaluate the use of blast furnace slag through the properties analysis by substituting a certain amount of blast furnace slag as an industrial by-product as a substitute for cement. The experimental results showed similar characteristics to those of using only cement when the blast furnace slag fine powder was used in an appropriate amount. Therefore, if a certain amount of cement is replaced with blast furnace slag powder, it can maintain similar quality, reduce natural resources and energy consumption, and reduce carbon dioxide emissions.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.156-157
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• 2022

The purpose of this study is to propose a 40MPa mortar mixed design model that applies the neural network theory to minimize wasted effort in trial and error. A mixed design model was applied to each of the 60 data using fly ash, blast furnace slag fine powder and thickened rice husk powder. And in the neural network model, the optimized connection weight was obtained by repeatedly applying it to the MATLAB. The completed mixed design model was demonstrated by analyzing and comparing the predicted values of the mixed design model with those measured in the actual compressive strength test. As a result of the mixed design verification experiment, the error rates of the double mixed non-cement mortar using blast furnace slag fine powder and rice husk powder at a height of 40MPa were 3.24% and 3.4%. Mixed with fly ash and rice husk powder had an error rate of 3.94% and 5.8%. The error rate of the triple mixed non-cement mortar of the rice husk powder, fly ash, and blast furnace slag fine powder was 2.5% and 5.1%.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.191-194
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• 1999

Recently in Korea, may workers have reported the effects of the granulated blast furnace slag[BFS] of high fineness on the strength development of slag cement. We have studied the effect of slag fineness on the strength development of mortar with curing conditions, in order to get the basic data of high strength concrete using BFS. In this paper, we discussed the effects of slag fineness and porosity of mortar and the reaction of slag in hardened slag cement.

• Resources Recycling
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• v.11 no.6
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• pp.24-30
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• 2002

Reduced and modified converter slag was ball milled and sieved to -200/+325 mesh. CaO,$SiO_2$, $Fe_2$$O_3$ was added to slag powder and mixed to make it similar to the composition of normal portlant cement. The pellet made of this powder was heated from $1250^{\circ}C$ to $1450^{\circ}C$ for 15 min～45 min. Most feasible condition for making slag cement clinker is the heating more than 20 min at $1450^{\circ}C$. The compressive strength of the mortar made of this slag cement clinker was better than that of normal port-lant cement in long time curing.