• Journal of the Korean Recycled Construction Resources Institute
• /
• v.4 no.4
• /
• pp.446-453
• /
• 2016

Structural capacity of water channel fabricated of concrete including blast furnace slag were investigated in this paper. An experimental study was consisted of materials test and structural test of concrete water channel. The mechanical properties of concrete including blast furnace slag were investigated. Ordinary Portland cement (OPC) was used as basic binder and the effect of the replacement of blast furnace slag for OPC was investigated. Experiments were performed to measure mechanical properties including compressive strength, elastic modulus and modulus of rupture. Test results show that the compressive strengths and modulus of ruptures of mixtures containing blast furnace slag were equivalent to those of OPC concrete. In addition, the structural capacity of concrete water channel with up to the replacement ratio of blast furnace slag of 45% was greater than the required strength in KS specification.

• Resources Recycling
• /
• v.24 no.6
• /
• pp.31-37
• /
• 2015

Ground granulated blast-furnace slag (GGBFS) which is by-product of steel industry has been recycled as a cement admixture though the other steel slags are used as aggregates. In this study, the electric arc furnace slag (EAFS) was used as a cement admixture after the reduction of iron oxide in the slag at the interface of molten slag and water quenching. Consequently, the reformed EAFS (REAFS) had higher grindability than that of granulated blast furnace slag. And in mortar tests, the strength properties of specimens using REAFS were 98% of plain specimens of GGBFS upto 20% replacement ratio of GGBFS with REAFS.

• Journal of the Korean Geosynthetics Society
• /
• v.21 no.4
• /
• pp.111-121
• /
• 2022

It has been reported that current amount of coal ash remains almost 100 million tons and 5.85 million tons of blast furnace slag are generated annually in Vietnam. Vietnam government has encouraged the industries to increase the use of coal ash and blast furnace slag as construction materials as well as in cement production institutionally. However, limited can be applied in the construction field yet. Therefore, in this study, basic performance analysis on five different kinds of fly ash from Vietnam was conducted. In addition, the performances of blast furnace slags generated in Vietnam and Korea were compared and evaluated. Soil stabilizer compressive strength test and solidified soil unconfined compressive strength test were conducted as the basic data for the development of soil stabilizer applied to the soil mixing method using fly ash and blast furnace slag generated in Vietnam. The results showed that the Vietnamese fly ash and blast furnace slag can be used as the raw materials for soil stabilization and improvement.

• Journal of the Korean Society for Heat Treatment
• /
• v.2 no.4
• /
• pp.69-72
• /
• 1989

• Journal of Korea Foundry Society
• /
• v.13 no.5
• /
• pp.420-423
• /
• 1993

• Journal of the Korean Geotechnical Society
• /
• v.25 no.6
• /
• pp.31-45
• /
• 2009

The aim of this study is to evaluate the applicability of Granulated Blast Furnace Slag to the development of the Powdered Ready-mixed Shotcrete. First of all, after accomplishing SEM analysis and Leaching Test, the laboratory and field experiments for evaluating the utility of Granulated Blast Furnace Slag were performed. As a result of SEM and Leaching test, the environmental stability was confirmed. That is, non-detection of harmful lists and dense shotcrete structure result from mixing Granulated Blast Furnace Slag. As a result of lab. and field test, Blast Furnace Slag is superior to Plain Batch in improving strength and durability. And it will be able to improve to some extent the problem caused by the delayed reaction of existing Granulated Blast Furnace Slag with alkali activated material. Also the proper amount of Granulated Blast Furnace Slag is estimated to be under 30%. Finally, it is possible that Granulated Blast Furnace Slag can apply to economical recycling and development of the Ready-mixed Shotcrete for its price is only about 5% of Silica-finne's price.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.27 no.12
• /
• pp.1734-1743
• /
• 2003

Aerosol generator using an electrically heated tube furnace is a stable apparatus to supply nanometer sized aerosols by using the evaporation and condensation processes. Using this method, we can generate highly concentrated polydisperse aerosols with relatively narrow size distribution. In this work, characteristics of particle size distribution, generated from a tube furnace, were experimentally investigated. We evaluated effects of several operation parameters on particle generation: temperature in the tube furnace, air flow rates through the tube, size of boat containing solid sodium chloride(NaCl). As the temperature increased, the geometric mean diameter increased and the total number concentration also increased. Dilution with air affected the size distribution of the particles due to coagulation. A smaller sized boat, which has small surface area to contact with air, brings smaller particles of narrow size distribution in comparison of that of a larger boat. Finally, we changed the electrical mobility diameter of aggregate sodium chloride particles by varying relative humidity of dilution air, and obtained non-aggregate sodium chloride particles, which are easy to generate exact monodisperse particles.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.21 no.7
• /
• pp.919-927
• /
• 1997

The main purpose of this study is to determine bifurcation as the primary instability of a glass melting furnace. Steady-state and unsteady characteristics of natural convection in the partially open cavity as appeared in a glass melting furnace is investigated by using numerical analysis. Three types of convection, such as steady laminar, unsteady periodic or unsteady quasi-periodic convection may occur according to the temperature difference between upper two isothermal surfaces along the depth of cavity in a glass melting furnace. In the temperature difference of 150-900 K between batch and free surface, the larger the temperature difference, the weaker the convection strength and unsteadiness. Since the glass viscosity is increasing exponentially in the lower temperature, the batch freezes the thermofluidic field especially below the surface of it. If the depth of cavity is 0.5 m, the bifurcation to time-dependent natural convection may occur in the range of 60-650 K. If that is 1.0 m, it may occur in the whole range of temperature difference.

• Journal of the Korea Institute of Building Construction
• /
• v.2 no.2
• /
• pp.145-150
• /
• 2002

The hydration of cement paste occurs when the cement is miked with water. During the hydration, hydration heat causes the thermal stress depending on the site of concrete and the cement content. Especially in the high-strength concrete, we must give care to the concrete due to its large cement content. In this study conduction calorimeter and concrete insulation hydration heat meter were used to investigation the hydration heat characteristics of cement and concrete. To reduce hydration heat of high-strength concrete, several types of replacement of fly-ash and blast-furnace slag powder were used in this experiment. As a result of this study, it was found that hydration heat of high-strength concrete was reduced by replacement of fly-ash and blast-furnace slag powder. In case of high-strength concrete using blast-furnace slag powder, the max-heat arrival time was delayed but an effect of heat reduction was lower than a case of high-strength concrete using fly-ash, because it was considered that the heat-dependence property of blast-furnace slag powder was higher than that of fly-ash.

• Journal of Conservation Science
• /
• v.35 no.4
• /
• pp.373-383
• /
• 2019

We characterized the smelting process and smelting furnace through scanning electron microscopy-energy dispersive spectroscopy, wavelength dispersive X-ray fluorescence, X-ray diffraction, and raman micro-spectroscopy with 13 relics including slags and furnace walls excavated from square-shaped building sites and pits of the Three Kingdoms site at the Ungyo site section I. Our results revealed that the principal components were FeO and SiO₂; and CuO, PbO, and ZnO were contained in small quantities. Furthermore, fayalite, magnetite, augite, copper, and cuprite were found. High contents of FeO or SiO₂ components seem to have been added to form fayalite to remove gangue in the smelting process. The relatively low content of S detected in the copper prills suggests that roasting was performed well. Cristobalite and mullite, which are minerals that indicate high-temperature found in the furnace wall, show that the smelting temperature was higher than 1,250℃. The findings of this study show a high possibility that the Wanju Ungyo site is smelting remains of copper ores, which are nonferrous metals, rather than iron. Various smelting byproducts excavated in this area in the future will help us better understand the copper smelting process that may have been performed since ancient times.