• Journal of the Korea Concrete Institute
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• v.11 no.4
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• pp.31-41
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• 1999

Blended Low Heat type cement is ground granulated blast furnace slag and fly ash mixed ternary with ordinary portland cement. From the viewpoint of X-ray patterns of domestic LHC, the main components of cement such as $C_2$S, $C_3$A, $C_3$S are considerably reduced. Therefore the heat evolution of LHC paste is 42cal/g lower than of OPC paste. At early age, the compressive strength development of LHC concrete is delayed, but the slump loss ratio of fresh concrete is reduced more than 20% with elapsed time. The penetrability of LHC is lower than that of OPC by 1/7.8 with the penetrability of chloride ion into the concrete until the age of 120 days. And the PD Index value of LHC is 0.44$\times$10-6 $\textrm{cm}^2$/s, which indicates only 39.3% of OPC. From the Mercury Intrusion Porosimetry test of cement past, we know that the pore size of LHC is more dense than that of OPC by production of C-S-H.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1655-1665
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• 2008

In order to investigate the applicability and suitability of the industrial by-products to landfill final cover, field pilot-scale lysimeter experiments were carried out. The mixture of loamy soil, bottom ash, and construction waste was placed as a cover material in lysimeter($2m{\times}6m{\times}1.2m$) which were constructed with cement brick, and then, volumetric water contents, pF value, and the quantity of runoff and seepage of treatment boxes filled with the mixture of loamy soil and the industrial by-products were monitored from July, 2007 to February, 2008. As a result, the case containing the mixture of bottom ash and loamy soil was most effective in engineering and hydrological properties and water retention ability.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.11a
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• pp.37-40
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• 2007

This study investigates the effect of the pre-mix cement to the physical properties of the concrete according to the various combinations of the binders and the silica fume types. The results are summarized as following. For the properties of the fresh, the fluidity in the case that OPC+cilica fume-blast-furnace slag is appropriate compared to OPC+cilica fume+fly ash. Expecially, it is favorable when pre-mix is used. The fluidity time of the A, B depending on silica fume types is favorable, but it is decreased on C. The air content depending on silica fume types is low when the fly ash is used. Specially, the air content in the case that pre-mix is used is low caused by the dispersion of the silica fume. For the properties of the hardened concrete, the compressive and flexible strength when the blast-furnace slag is pre-mixed are high, and they exceed OPC. The strength depending on the silica fume types is high on B, and the strength of the others is similar.

• Korean Journal of Materials Research
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• v.20 no.1
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• pp.1-6
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• 2010

Geopolymer materials are attractive as inorganic binders due to their superior mechanical and eco-friendly properties. In the current study, geopolymer-based cement was prepared using aluminosilicate minerals from fly-ash with KOH as an alkaline-activator and $Na_2SiO_3$ as liquid glass. Then, calcium carbonate powder from a clam shell was mixed with the geopolymer and the mixture was coated on a concrete surface to provide points of attachment for environmental organisms to grow on the geopolymers. We investigated the effect of the shell powder grain size on the microstructure and bonding property of the geopolymers. A homogeneous geopolymer layer coated well on the concrete surface via aluminosilicate bonding, but the adhesiveness of the shell powder on the geopolymer cement was dependent on the grain size of the shell powder. Superior adhesive characteristics were shown in the shell powder of large grain size due to the deep penetration into the geopolymer by their large weight. This kind of coating can be applied to the adhesiveness of eco-materials on the surface of seaside or riverside blocks.

• Journal of the Society of Disaster Information
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• v.9 no.2
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• pp.128-136
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• 2013

The current contractor for use in performance compared to the performance study of industrial byproducts. Due to the stagnation of the construction business and the rise of raw materials, the contractor of the cost savings and environmental issues, and present a variety of ways for research actively being. Through special about the compressive strength characteristics of the mixed concrete, carbonation resistance and chloride penetration resistance of this study, previous studies have been a lot of progress, industrial byproducts, fly ash and blast furnace slag concrete structures were applied to evaluate.

• Geomechanics and Engineering
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• v.24 no.1
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• pp.81-89
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• 2021

Uniaxial compression tests were conducted on sandstone-CGFB composite samples with different interface angles, and their strength, acoustic emission (AE), and failure characteristics were investigated. Three macro-failure patterns were identified: the splitting failure accompanied by local spalling failure in CGFB (Type-I), the mixed failure with small sliding failure along with the interface and Type-I failure (Type-II), and the sliding failure along with the interface (Type-III). With an increase of interface angle β measured horizontally, the macro-failure pattern changed from Type-I to Type-II, and then to Type-III, and the uniaxial compressive strength and elastic modulus generally decreased. Due to the small sliding failure along with the interface in the composite sample with β of 45°, AE events underwent fluctuations in peak values at the later post-peak failure stage. The composite samples with β of 60° occurred Type-III failure before the completion of initial compaction stage, and the post-peak stress-time curve initially exhibited a slow decrease, followed by a steep linear drop with peaks in AE events.

• Journal of the Korean Applied Science and Technology
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• v.41 no.2
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• pp.520-529
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• 2024

Lycium barbarum extract has a high potential to be developed as a health functional food due to the various health-promoting effects of Lycium barbarum. This study analyzed changes in nutritional and functional components depending on the extraction solvent (purified water and a mixture of purified water and alcohol) and the condition of the sample. The nutritional components (carbohydrates, protein, fat, ash), organic acids, amino acids, total phenolic compounds, and total flavonoids of the extract produced during the extraction process were analyzed. The nutritional composition and functional substances of the extracts showed some differences depending on the type of solvent and the condition of the sample. The amounts of crude protein (7.61%), crude fat (1.63%), carbohydrate (90.22%), and ash (0.54%) of dried Lycium barbarum extract using purified water as a solvent were similar to those of the powder sample extract. The highest content of citric acid was 4.31 mg/mL, similar to the case of acetic acid, when the powder sample used a mixture of purified water and alcohol as a solvent. The highest amino acid content was 357.39 mg/mL when the powder sample was mixed with purified water and alcohol as a solvent. The total amount of phenolic compounds was 686.16 g/L when the powder sample was extracted with a mixture of purified water and alcohol as a solvent. The highest total flavonoid content was 111.32 g/L when the powder sample was extracted with a mixture of purified water and alcohol as a solvent.

• Particle and aerosol research
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• v.12 no.2
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• pp.43-50
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• 2016

The influence of basalt fibres on the compressive strength of the geopolymer type binders has been studied. For the experiments 2 types of the basalt fibres were used, namely chopped and spooled fibres. Both types of basalt fibres were 7-10 micron thick in diameter and cut into pieces of 6 mm length. The fibres were mixed with 1% weight to the fly ash powder, followed by the addition of the activator solution (8M NaOH). The pastes obtained were cured at $70^{\circ}C$ for 20 h revealing compact bodies. Compressive strength was measured after 7 days and microstructure observation performed with SEM. The cube bodies ($2{\times}2{\times}2cm$) reveal compressive strength of 47.25(4.03) MPa, while it decreased to 34.0(9.05) MPa in spooled basalt fibres and to 17.33(5.86) MPa in the chopped basalt fibres containing binder, i.e 76% and 36% of the strength without fibres, respectively. The much weaker compressive strength of the chopped fibres containing binder is related to the absence of significant adhesion between the geopolymer binder and the basalt fibres, forming voids instead. Alkali leaching effect of basalt fibres could probably explain the drop in the compressive strength with spooled and chopped fibres, respectively.

• Journal of the Korean GEO-environmental Society
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• v.19 no.6
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• pp.13-22
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• 2018

The southwestern part of Korean Peninsula, which length is about 13,000 km, is largely formed with soft cohesive soil ground and when it is developed, the low bearing capacity and excessive settlement of soft ground give many problems. In particular, a lot of clayey soil is deserted due to high moisture content and weakness, and areas formed with soft ground. In this study it was performed unconfined compression test, CBR tests, laboratory frost heaving test, and wheel tracking test in order to determine the optimum mixture ratio of paper sludge ash added chemical stabilizer with soft soil for consideration of its frost heaving and strength characteristics. As a results of the above experiments, when the soft soil is mixed with 6% of chemical stabilizer to improve the soft soil for utilizing as a subgrade soil material. It is satisfied the quality standard of fill materials, and the results of this research are expected to be used as an appropriate usage standard for utilization of on-site soil generated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.2
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• pp.59-66
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• 1988

At the present time, annually about 2 million tons of coal ashes are generated from thermal power plants in Korea, however, they are dumped into ash ponds mixed with sea water very expensively. In this thesis, engineering characteristics of bituminous and anthracite ashes are studied to utilize them as construction materials. The coal ash is non-plactic material and its grain size falls in the range of silt, but it has better soil engineering characteristics than general soils of same grain size. For example, the permeability, shearing strength, CBR, and consolidation properties match to that of sandy soils, moreover, strengthening by hydration can be expected with the lapse of year because of CaO presence in the components. So, utilizing those coal ashes in a productive way as reclamation or banking materials is expected.