• Journal of the Korean Ceramic Society
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• v.49 no.5
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• pp.442-447
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• 2012

This study investigated on the early hydration and physical characteristics of BFS by pH variation. NaOH solution was used as a pH activator. In the range from pH 12 to pH 14, Experiment was compared the hydration propertied of OPC(Ordinary Portland Cement) and BFS(Blast Furnace BFS) and BFS containing 2 wt% of gypsum. It was found that CAH(Calcium Aluminate Hydrates) phases and CSH(Calcium Silicate Hydrates) phases were formed during the early hydration of BFS, and that CAH phases, CSH phases and ettringites were formed during the early hydration of BFS containing 2 wt% of gypsum. Furthermore, early hydration of BFS and BFS containing 2 wt% of gypsum were faster then OPC at pH 14, and the 1 day compressive strength of BFS increased by approximately 30% compared to OPC, and BFS containing 2 wt% of gypsum also increased by approximately 40% compared to OPC.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.1
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• pp.90-99
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• 2015

This study examined dynamic and characteristics and chloride penetration of concrete mixed with large amount of FA and BFS, which are considered for positive application to construction fields with purpose of long-tern durability of concrete structures. 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. For relation between compression strength and diffusion coefficient of FA and BFS concrete, as strength increased, diffusion coefficient decreased. In this study, when mixing FA and BFS to concrete for long-run durability and restraint against chloride penetration, for FA, mixing it to concrete with less or equivalent 30% of replacement rate was most efficient. And for BFS, as fineness was higher and mixing it to concrete with less or equivalent 50% of replacement rate, there were results of higher strength compared to OPC and more efficient restraint of chloride ions.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.40-41
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• 2014

As a result of strength test on 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 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. In this study, when mixing BFS to concrete for long-run durability and restraint against chloride penetration, for BFS, as fineness was higher and mixing it to concrete with less or equivalent 50% of replacement rate, there were results of higher strength compared to OPC and more efficient restraint of chloride ions.

• Journal of the Korea Institute of Building Construction
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• v.9 no.6
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• pp.71-78
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• 2009

The analysis of the effect of loading on chloride penetration into concrete is very important. In this study, we confirmed that the chloride penetration rates for plain and BFS concrete were increased by 47% and 89% under compressive stress, respectively. The diffusion coefficient of BFS concrete was lower than for conventional concrete with no BFS, no loads, and under stressed states. Therefore, BFS substitution plays an important role in the repression of chloride penetration even under compressive stress. Under compressive stress,the diffusion coefficient for BFS concrete was higher with increasing stress, and this was also the case for plain concrete. However, BFS concrete was strongly influenced by compressive stress in comparison to plain concrete. We investigated the effect of the difference of specific surfaces on the diffusion coefficient. As a result, the larger specific surface of BFS exhibited a lower diffusion coefficient. This tendency was most pronounced under the high stress conditions.

• Journal of the Korean Ceramic Society
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• v.52 no.6
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• pp.483-488
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• 2015

Blast furnace slag(BFS) is well known for its hardening mechanism in ordinary Portland cement with alkali activation due to its latent hydraulic property. The possibility of using calcium compound as activator for BFS has been investigated in this study. The hydration properties of calcium compound activated BFS binders were explored using heat of hydration, powder X-ray diffraction and compressive strength testing. Heat of hydration results indicate that the hydration heat of BFS is lower than OPC paste by about 50%. And ettringite as hydration product was formed continuously as the calcium sulfate was decreased. The maximum compressive strength of hardened BFS mortar at 28 days is confirmed to be 83% as compared with hardened OPC mortar.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.297-300
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• 1999

This study was carried out to present the properties of fresh concrete made with ground granulated blast-furnace slag (BFS) powder with variations of blaine and content, and to estimate the utilization of the BFS concrete as admixtural materials for concrete structures of the building. According to the results, the fluidity of concrete which BFS dosage rate was 45% had the considerable difference from that of concrete which BFS dosage rate was not bigger than 35%. Also, the diminution of bleeding was appeared with the increase of blaine and content of BFS. It is concluded that BFS concrete of low blaine can be used effectively in concrete structures of the building.

• Journal of the Korean Ceramic Society
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• v.44 no.11
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• pp.618-621
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• 2007

In this study, flint glass batches with blast furnace slag (BFS) were prepared and the contribution of the BFS to the fining of melts was studied through investigations of the melting and fining characteristics. Additionally, a sulfur redox reaction for BFS-doped melts was examined by square wave voltammetry (SWV). The results of the melting & fining test showed that BFS improved the fining of the melts. In a voltammogram of BFS-doped melts, two reduction peaks were shown at high frequencies while only one peak appeared at low frequencies. The peaks were located at a potential that was similar to those of melts fined by sulfate. From those results it was concluded that sulfide ($S^{2-}$) in BFS has effects in glass melts that are identical to those of sulfate ($SO_4^{2-}$).

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.53-54
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• 2015

As the result of uniaxial compression strength test on the CLMS mixing BFS and SS with BFS 4000, it required to determine the desired strength through increasing unit quantity of cement in mixing process because of dramatic strength deterioration of strength according to increasing replacing rate. In this study's result, regardless of differences in fine aggregates used, in order to get uniaxial compression strength in the scope exceeding criteria of minimum strength for applying to the field, the most reasonable combination was to mix replacing BFS with fineness of 6000 in 30%. For the CLMS mixing BFS and SS, in order to improve flow ability by securing quantity of minimum unit and to repress bleeding rate with securing uniaxial compress strength considering the field applicability, regardless of differences in fine aggregates used, to mix BFS over 6000 in 30% was most effective.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.269-274
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• 2000

As a result of the reduction of natural aggregate, most of developed country have been studied the utilization of Blast-furnace Slag(BFS) as aggregate of concrete. bur, in korea there are only basic study about these even though other country are using Blast-furnace Slag production of Ready Mixed Concrete. According, in this study, we carried out fundamental experiments in order to know the material properties of BFS and possibilities of the BFS as fine aggregate of concrete. It is included that analysis concerning material properties of BFS as like specific gravity, absorption. unit weigth, grading including investigation of the surface shape by SEM, also, analysis concerning properties of concrete with BFS as like air-content surface slump. compressive strength .etc.

• Journal of the Korean Ceramic Society
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• v.45 no.2
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• pp.90-93
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• 2008

The oxygen gas behavior in PDP (plasma Display Panel) glass melts doped with sulfate ($SO_4^{-2}$) or blast furnace slag (BFS, $S^{2-}$) or both by means of yttria-stabilized zirconia (YSZ) electrodes was observed after the first fining. The temperature dependence of oxygen equilibrium pressure ($P_{O2}$) in each melt showed typical behavior, namely $P_{O2}$ decreased as temperature decreased. This suggests that an oxidation of $S^{4+}$ to $S^{6+}$ took place. However, the $P_{O2}$-value at constant temperature increased in the following order: BFS$P_{O2}$ of the melt doped with sulfate+BFS was much lower than that of the melt with only sulfate, although only 10% of sulfur was added by the BFS. This behavior can be explained by the redox reaction between sulfide ions in the BFS and dissolved oxygen ions in the melt during the first fining.