• Journal of the Korean Geotechnical Society
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• v.23 no.11
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• pp.15-26
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• 2007

Los Angeles abrasion loss test has usally been applied to the quarry for the purpose of aggregate hardness estimation. 324 blocks from 25 sites of Kyeongsang basin samples of sedimentary rock were examined and tested in laboratary. This paper found that L. A. abrasion loss test is a good method to estimate engineering index such as uniaxial compressive strength, elastic modulus, indirect tensile strength, point load strength index, Schmidt hammer rebound value of sedimentary rocks with high correlation factor. Engineers will prefer L. A. abrasion loss test to the other one for design and construction as this method is quick and easy.

• Journal of Soil and Groundwater Environment
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• v.12 no.4
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• pp.8-15
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• 2007

Geotechnical and environmental properties of stone fillers are analyzed by several laboratory experiment to identify the possibility of recycling fillers and sewage dredged soils as construction materials. The result of geotechnjical test shows that the sewage dredged soil is a sandy soil which contains 70-80% sand and is useful as an aggregate of construction site. Stone filler has large fine content, which may disqualifies the use as construction materials. However, this material is still useful as a filler in stone quarries or finished mines. From the environmental test, the liquids leached from two types of materials have satisfied the standard of chemical substances in the soil environment law and no harmful effect in ground pollution is expected when recycling.

• The Korean Journal of Ecology
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• v.27 no.3
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• pp.121-126
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• 2004

The purpose of this study was to investigate the distribution of epiphytic lichens that growing near the thermoelectric power plant to obtain a basic data for air environmental evaluation around the power plant. The study areas were all 12 places including ten sites near the power plant and two sites for control. All the number of lichens appeared in this study areas were 27 species. It showed to 4∼6 species within 4㎞ from the power plant, and coverage also was low. As receding from the power plant, both the number of species and overage increased. Parmelia tinctorum sensitive to air pollution did not appear within 4㎞ from the power plant, and it was regarded as the sensitive kind to air pollution. Lepraria sp.(13.40%), Parmelia austrosinensis (13.40%), and Dirinaria applanaita (13.40%) were distributed in all sites, and it could infer that they had tolerance to air pollution. The IAP (Index of Atmosphere Purity) values in Sadungdong Apsan, Seksangeabal and the Power plant were four times as low as those in Mt, Yeonwha, and it could infer that the air in those areas was not good. It was high IAP values as being distant from the power plant.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.3
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• pp.247-252
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• 2017

The aim of this research is the feasibility analysis of the reject ash premixed cement mortar with combined aggregate. Namely, for the combined aggregate with two different qualities of aggregates, a fundamental properties of cement mortar was evaluated depending on various replacing ratios of reject ash(Ri). According to the experimental results, the combined aggregate consisted with low-quality aggregate and sea sand did not change the flow value depending on the reject ash while the combined aggregates consisted with low quality aggregate and sea sand; and consisted exploded debris sand and sea sand the increasing reject ash increased the air content with increased replacing ratio of reject ash. In the case of compressive strength, as the replacing ratio of reject ash was increased, the compressive strength was increased. It is considered that when 5% of reject ash replacing ratio made similar quality of cement mortar with favorable quality aggregate, hence, it can be suggested that 5% replacement of reject ash for desirable fluidity and compressive strength of concrete.

• Explosives and Blasting
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• v.33 no.1
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• pp.1-12
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• 2015

In this study, the domestic bench blasting sites were researched to set the blast coefficient C according to the type of rock and type of industry. With the use of the experimental data on the representative industrial explosives and the data of the manufacturers'data on explosives, powder coefficient e was set up. The blast coefficient C was 0.21~0.30 when the average value for 5 representative kinds of rocks including granite was searched. The blast coefficient C for quarrying, mining and construction sites were 0.22, 0.13 and 0.26 respectively. On the other hand, powder coefficient e was obtained in four elements such as reactive energy, ballistic mortar test, VOD, Langefors'strength per unit weight. e value for emulsion which is one of the representative explosives was found to be 1 while those of high performance emulsion and ANFO were found to be 0.9 and 1, respectively.

• The Journal of the Petrological Society of Korea
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• v.20 no.4
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• pp.219-230
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• 2011

Jurassic granite from Hapcheon was analysed with respect to the characteristics of the rock cleavage. The phases of distribution of microcracks were well evidenced from the enlarged photomicrographs(${\times}6.7$) of the thin section. The planes of principal set of microcracks are parallel to the rift plane and those of secondary set are parallel to the grain plane. These rift and grain microcracks are mutually near-perpendicular on the hardway planes. Consequently the rock cleavage of Jurassic granite from the studied quarry can be related to the preferred orientation of microcracks. Microcrack parameters such as number, length and density show an order of rift > grain > hardway. These results indicate a relative magnitude of the rock cleavage. Meanwhile, brazilian tensile strengths were measured with respect to the six directions. The results revealed a strong correlation between mechanical property with microcrack parameters.

• Journal of Korean Society on Water Environment
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• v.21 no.4
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• pp.368-378
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• 2005

Inorganic matters originated from stone quarries and manufacturing plants could alter the ecological characteristics of adjacent aquatic systems, especially the structure and function of benthic macroinvertebrate community. In such situation, the locality of stone quarry and the quantity of inorganic matters would be important factors that determined the disturbing strength to the benthic macroinvertebrate community. Locality patterns of stone quarries were classified into 3 types in relation to the stream ecosystem; stream-proximity, upstream-inclusion and tributary-inclusion type. In the result of species:abundance analysis, stone quarry B (upstream-inclusion type) showed geometric distribution, while others showed broken-stick distribution pattern. The benthic macroinvertebrate communities closer to stone quarries showed smaller species numbers and standing crops among all types of stone quarries. However the values of species evenness index were not seriously different between controls and directly affected sites. These results indicated that the effect of inorganic disturbance would differ from those of organic pollution that induced the highly dominant state occupied by tolerant species. Number of occurred species, standing crops, community indices and biotic indices indicated that the community of upstream-inclusion type was the most seriously damaged from the inorganic disturbance, and the community would be very simple and unstable. Tributary-inclusion stone quarry heavily damaged to tributary system in biologically, but influence to the main stream seemed to be depended on the scale of main stream. Among 3 types of stone quarry localities, stream-proximity type induced the least damages to benthic macroinvertebrate community, though the degrees of damage were different along with distances between stream and stone quarry.

• Journal of the Korean Geosynthetics Society
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• v.11 no.1
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• pp.35-45
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• 2012

Dynamic characteristics of decomposed granite soil mixed with stone sludge and bentonite were investigated to figure out adequate applications of stone sludge, A total of 16 specimens with different stone sludge contents of 0%, 5%, 10%, 15% and bentonite with 0%, 5%, 10%, 15% were prepared. Resonant column tests were carried out on each specimen at different confining pressure. The results showed that the optimum mixing ratio which can satisfy the maximum shear modulus and the minimum damping ratio of the decomposed granite soils ranges from 5% to 10% respectively.

• International Journal of Highway Engineering
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• v.14 no.3
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• pp.69-76
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• 2012

A recent shortage in Korean aggregate market leads a social demand to utilize recycled aggregate to more advanced level, such as the use in concrete structures or paving materials for surface and base layers. Government announced a recycled aggregate guideline in 2009 to provide an institutional framework for recycled aggregate in such an up-scaled use. The use of recycled aggregate in such use; however, is very minimal. This paper evaluates the validity of the impurity content criteria of recycled aggregate for lean concrete base through a series of material tests. The analysis results shows that reclaimed asphalt pavement (RAP) in recycled aggregate not only influence a strength lean concrete adversely, but also influence negatively on an absorption and abrasion characteristics of aggregate system significantly that made those two indices lower. Since absorption and abrasion characteristics are very important indices for recycled aggregate quality, RAP in recycled aggregate could significantly mislead the recycled aggregate qualification. This paper provides a suggestion to resolve these problems.

• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.25-32
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• 2013

This study examined the status of the vegetation around Gangcheonsan provincial park located in Sunchang-gun in Jeollabuk-do and Damyang-gun in Jeollanam-do from June 4 to October 12, 2011. Gangcheonsan vegetation was arranged 9 plant communities in accordance with data of 28 releves. Major forest vegetation included Quercus variabilis communityand Quercus variabilis-Quercus serrata community, Pinus densiflora community, and Pinus densiflora-Quercus variabilis community (evergreen coniferous forest in all), and Phyllostachys nigra var. henonis community (plantation). Wetland vegetation included Salix gracilistyla community (riverbank forests), Phragmites japonica community, and Polygonia thunbergii community. Gangcheonsan Provincial Park has beautiful scenery that is in harmony with fantastically-shaped rocks, waterfalls, and valleys and conserves a specific plant community habitat distributed through the forest wetlands including its valleys. It is necessary to conduct long-term monitoring with its focus on Pinus densiflora community, Lycoris koreana community, and Lycoris squamigera community in the provincial park to grasp the characteristics of ecological inhabit changes in major communities and provide active methods for conservation, restoration, and publicity.