• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.2
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• pp.100-105
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• 2005

Two species of fish and five species of marine invertebrate showed different tolerances to the toxicity of composite slag and bituminaus coal. Especially, Hemicentrotus pulcherrimus and young Haliotis discus hannai displayed marked differences in tolerance from. H. pulcherrimus and young H. discus hannai showed lethal effects at higher concentrations than those concentrations of the composite slag in the 1.0 and $0.4\%$ range, respectively. H. pulcherrimus showed no lethal effects at a lower concentration of $1.0\%$ composite slag and some differences in the rate of oxygen consumption with this concentration of composite slag. The lethal effects of bituminous coal on marine and fisheries organisms, even with higher concentrations, were not observed. At a higher concentration than that of 500 mg/L (ppm) of bituminous coal, decrease effects appeared in the rate of oxygen consumption of the experimental organisms. Taking into consideration that the experimental concentration of composite slag and bituminous coal were impracticable in the ocean, the results of this experiment suggest that composite slag and bituminous coal pose no real threat to marine or fisheries organisms.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.207-214
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• 2000

Sand Compaction Pile method is one of the widely used ground improvement techniques at loose sand or soft clay ground in Asian countries. However, due to environmental and economical problems concerning shortage of sand resources alternative materials are needed to substitute sand for SCP. This study is on the applicability of slag as an alternative material SCP. Consolidation and direct shear test are performed for the slag-clay composite specimens to find out the positive effects of consolidation rate and shear resistance of slag reinforced ground. The result shows that slag has similar effects with sand in consolidation and shear resistance behavior in composite ground, which says slag can be used as alternative material of sand for SCP.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.318-321
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• 2003

Steel slag is produced during steel making process. Compared with the blast furnace slag, converter slag has the expansibility due to the reaction with water and free CaO. Therefore it is specified in Standard Specification for Concrete in Korea that steel slag aggregate must not be used in concrete. In this study, atomized steel slag aggregate is conducted from converter slag by the atomizing method. Atomized steel slag and conventional converter slag are same in its composite by nature in the converter but compounds of the composite become different because of different method of slag treatment. Especially atomized steel slag aggregate overcomes expansibility that is the weak point for usage. It is researched whether it has the possibility, suitability for fine aggregate in concrete. Slump and air content are measured in fresh concrete, compressive and bending strength in hardened concrete. These is compared with control concrete with washed sand.

• Composites Research
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• v.26 no.4
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• pp.218-222
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• 2013

This study demonstrated that a slag, an industrial solid waste, can be used as a structural reinforcement. The mechanical properties(tensile strength and Elastic modulus) of slag reinforced composite(SRC) was investigated as functions of slag particle size (8~12 ${\mu}m$ and 12~16 ${\mu}m$) and volume fraction (0-40 vol.%). In order to investigate the interface and a degree of particle dispersion which have an effect on mechanical properties, optical microscopic images were taken. The results of tensile tests showed that the tensile strength decreased with an increase in slag volume fraction and particle size. The elastic modulus increased with an increase in slag volume fraction and particle size except for 30 vol.% SRC. The tensile strength decreased with an increase in slag particle size. The microscopic picture showed SRC has fine degree of particle dispersion at low slag volume fraction. SRC has a good interface at every volume fraction. However particle cluster was incorporated with an increase in slag volume fraction.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.613-620
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• 2002

Sand Compaction Pile(SCP) is a soil improvement method that a sand charge is introduced into the pipe, and the pipe is withdrawn part away while the sand pile is compacted and its diameter is enlarged. The sand used in this method should be of good quality. In Korea, crushed stone and washed sea sand are used frequently in SCP. However, use of these materials is restricted because of environmental problem and deficiency of supply. In the copper smelting process, about 0.7 million tons of copper slag are produced in Korea. The range of particle size distribution of copper slag is from 0.15mm to 5mm, so it can be a substitute for sand, and the relatively high specific gravity compared with the sand, is its characteristic. Copper slag is hyaline and so stable environmentally that in foreign country, such as Japan, Germany etc., it is widely used in harbor, revetment and offshore structure construction works. Therefore, in this study, the several laboratory tests were peformed to evaluate the applicability of copper slag as a substitute for sand of SCP. From the mechanical property test, the characteristics of sand and copper slag were compared and analyzed, and from laboratory model test, the strength of composite ground was compared and analyzed by monitoring the stress and ground settlement of clay, SCP and copper slag compaction pile. Specially, this study focused on the application of copper slag as sand substitute in SCP pilot tests based on laboratory tests results.

• Applied Chemistry for Engineering
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• v.25 no.4
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• pp.380-385
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• 2014

Spherical atomizing reduction steel slag was prepared by atomizing technology using reduction steel slag (ladle furnace slag, LFS) generated from steel industry. In order to develop the mass-recycling technology of atomizing reduction steel slag, polymer concrete composite was prepared using spherical atomizing reduction steel slag instead of fine aggregate (river sand) and coarse aggregate (crushed aggregate), depending on the grain size. Different polymer concrete specimens were prepared with the various proportions of polymer binder and replacement ratios of atomizing reduction steel slag in order to investigate the characteristics of polymer concrete composite. Results showed that compressive strengths of polymer concrete specimens decreased with the increase of replacement ratios of atomizing reduction steel slag, but flexural strengths of the specimens showed a maximum strength at the 50% of replacement ratios of atomizing reduction steel slag. It was concluded that addition ratio of polymer binder, which affect greatly on the prime cost of production of polymer concrete, could be reduced by maximum 18.2 vol% because the workability of the polymer concrete was remarkably improved by using the atomizing reduction steel slag. However, further study is required because the mechanical strength of the specimen using atomizing reduction steel slag was greatly reduced in hot water resistance test.

• Applied Chemistry for Engineering
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• v.23 no.4
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• pp.409-415
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• 2012

To recycle the steel slag as manufactured composite materials of polymer concretes, we used the atomizing method to make round aggregates from steel slag, which is treated as industrial wastes. A round rapid-cooled steel slag was used to replace fine aggregate (river sand) or coarse aggregate (crushed aggregate), depending on the grain size. To examine general physical properties of polymer concrete composites manufactured from rapid-cooled steel slag, the polymer concrete specimen with various proportions depending on the addition ratio of polymer binder and replacement ratio of rapid-cooled steel slag were manufactured. In the result of the tests, the mechanical strength of the specimen made by replacing the optimum amount of rapid-cooled steel slag increased notably (maximum compressive strength 117.1 MPa), and the use of polymer binder, which had the most impact on the production cost of polymer concrete composites, could be remarkably reduced. However, the mechanical strength of the specimen was markedly reduced in hot water resistance test of polymer concrete composite.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.2
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• pp.158-165
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• 2019

The purpose of this study is to investigate analytically the flexural behavior of beam reinforced by an alkali-activated slag-based fiber-reinforced composite. The materials and mixture proportion were selected to manufacture an alkali-activated slag-based fiber-reinforced composite with high tensile strain capacity over 7% and compressive strength and tension tests were performed. The composite showed a compressive strength of 32.7MPa, a tensile strength of 8.43MPa, and a tensile strain capacity of 7.52%. In order to analyze the flexural behavior of beams reinforced by ultra-high-ductile composite, nonlinear sectional analysis was peformed for four types of beams. Analysis showed that the flexural strength of beam reinforced partially by ultra-high-ductile composite increased by 8.0%, and the flexural strength of beam reinforced fully by ultra-high-ductile composite increased by 24.7%. It was found that the main reason of low improvement in flexural strength is the low tensile strain at the bottom of beam. The tensile strain at bottom corresponding to the flexural strength was 1.38% which was 18.4% of tensile strain capacity of the composite.

• Computers and Concrete
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• v.21 no.3
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• pp.231-237
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• 2018

A strain-hardening highly ductile composite based on an alkali-activated slag binder and synthetic fibers is a promising construction material due to its excellent tensile behavior and owing to the ecofriendly characteristics of its binder. This study investigated the effect of different types of synthetic fibers and water-to-binder ratios on the compressive strength and tensile behavior of slag-based cementless composites. Alkali-activated slag was used as a binder and water-to-binder ratios of 0.35, 0.45, and 0.55 were considered. Three types of fibers, polypropylene fiber, polyethylene (PE) fiber, and polyparaphenylene-benzobisethiazole (PBO) fiber, were used as reinforcing fibers, and compression and uniaxial tension tests were performed. The test results showed that the PE fiber series composites exhibited superior tensile behavior in terms of the tensile strain capacity and crack patterns while PBO fiber series composites had high tensile strength levels and tight crack widths and spacing distances.

• Journal of Urban Science
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• v.9 no.1
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• pp.1-6
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• 2020

The thermoelectric characteristics of alkali activated slag composites containing multi-walled carbon nanotubes (MWCNT) was investigated in the present study. Three different MWCNT contents and exposed temperatures were considered, and their thermoelectric-related properties and internal structures were analyzed. It was found that the alkali activated slag composite with MWCNT 2.0 wt.% and the exposed temperature of 150℃ were the optimal condition to obtain the highest Seebeck coefficient and power factor. Based on the feasibility study, the extended size thermoelectric module with 130 elements was fabricated, and tested the electricity production capacity. Consequently, the present thermoelectric module produced 30.83 ㎼ of electricity at ∆T=178.4℃.