• Journal of the Korean earth science society
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• v.30 no.1
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• pp.33-39
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• 2009

This paper presents the occurrence and characteristics of the basaltic andesite-siltstone peperite in the lower part of the Gyehwari Formation (Cretaceous), Buan-gun, Jeonbuk province, SW Korea. The peperite is associated with tabular basaltic andesite body, concordantly intercalated with red siltstone and silty sandstone interbeds of floodplain facies. Development of the peperite along the upper margin of the andesite and its textural transition from a dispersed blocky type inward into a closely packed type collectively indicate an intrusive origin (?sill) of the andesite. Magma intrusion and subsequent peperite formation suggest an active syndepositional volcanism since the early stage of evolution of the Gyehwa Basin. The andesite is dated at Late Cretaceous (Santonian) by K-Ar whole-rock radiometric method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5551-5557
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• 2012

Sedimentary rocks dug up in construction fields are mostly stockpiled for landfill disposal, leading to an increase in construction costs and construction inefficiency. After screening, some of the sandstone can be used as aggregate; however, most of the shale ends up as industrial waste in practice. In this study, to stabilize the demand and develop resources for alternative aggregates of concrete, the potential use of shale, which is widely distributed in the Daegu-Kyeongbuk region, as a concrete aggregate was evaluated. Red and black shale exported from a Daegu excavation site was selected for use in the experiments and evaluated by comparing with hornfels, which is widely used as a coarse aggregate and is a type of andesite and metamorphosed sedimentary rock. The physical properties of the aggregate were evaluated in accordance with the test methods of KS F 2527 "crushed concrete aggregate," and the compressive strength against the shale aggregate replacement ratio was measured. The compressive strength of the concrete after 28 days was 30.8 MPa when the black shale replaced 100% of the aggregate in the concrete and 31.1 MPa when the red shale replaced 100% of the aggregate in the concrete. Compared with the compressive strength of 37.5 MPa for concrete prepared by using plain aggregate, using shale as a substitute for the aggregate produced an average compressive strength that was 82% of normal concrete.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.8
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• pp.4033-4038
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• 2013

Sedimentary rocks from construction waste are discarded through open storage and landfilling, which causes an increase in construction cost and inefficient of execution of works. Some sandstone are selected and utilized as aggregates, but shale is buried as industrial waste. Therefore, in this research, we evaluated weathering properties of shale aggregate that is widely distributed throughout Daegu-Kyeongbuk region and freeze-thaw characteristics of concrete according to the replacement ratio of shale aggregate, in an effort to stabilize aggregate supply-demand in Daegu-Kyeongbuk region and develop alternative aggregates. We used red shale and black shale in the experiment, which were exported from a construction site in Deagu. We verified the usage of shale as a concrete aggregate by comparing andesite, which is broadly used as a thick aggregate for concrete, to hornfels, which is a metamorphic sedimentary rock. As a result of the experiment, we observed no degradation phenomenon for andesite and hornfels. However, a part of country rock containing black shale was found to be exfoliated. Red shale started having cracks in the direction of stratification after 1.5 months of direct exposure, and it broke into smaller pieces after approximately 4 months. After 300 cycles of freeze-thaw process on the concrete manufactured according to the replacement ratio of shale aggregate, the modulus of elasticity was 97% for plain and 95% for hornfels. In the case of RS_100, it was 57% after 210 cycles, and for BS_100, it was 54% after 240 cycles. Therefore, we established that, as the number of repetition increases, the freeze-thaw resistance decreases dramatically.

• Journal of Korean Society of Forest Science
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• v.47 no.1
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• pp.52-61
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• 1980

This study is carried out to learn the properties of forest soils in Korea and propose the reasonable management methods of forest land. Among 178 soil series surveyed until now in Korea forest soils include 64 series broken down according to the weathered products into 5 categories such as residual materials on mountain and hill, residual materials on rolling and hill, colluvial materials on local valley and fans, alluvial materials and volcanic ash soils. What discussed in this paper are classification system, parent rocks, texture class and drainage conditions of Korean forest soils. The characteristics of Korean forest soil properties classified in U.S.D.A. soil classification system are as follows: 1. Residual soils on mountain and hill (29 soil series) are almost Lithosols without any distinct soil profile development. They have loamy skeletal (11 series), coarse loamy (5 series), fine loamy (3 series), and fine clayey soils (3 series). Their drainage conditions are somewhat excessively drained in 16 series and well drained in 7 series. 2. Residual soils on rolling and hill (19 series) are Red-Yellow Podzolic soils with well developed soil profiles. They have coarse and fine loamy texture in 12 series and fine clayey texture in 5 series mostly with well drained condition. 3. Colluvial soils on local valley and fans (13 series) include mostly Regosols and some Red-Yellow Podzolic Soils and Acid Brown Forest Soils. They have loamy skeletal (4 series), coarse loamy (3 series), fine loamy (3 series), and fine clayey soils (2 series) with well drained condition. 4. Soil textures of weathered products of parent rocks are as follows: 1) Parent rocks producing coarse texture soils are rhyolite, granite gneiss, schist, shale, sandstone, siltstone, and conglomerate. 2) Parent rocks producing fine and heavy texture soils are limestone, basalt, gabbro, and andesite porphyry. 3) Granite is a parent rock producing various textured soils.

• Journal of the Korea Concrete Institute
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• v.20 no.6
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• pp.689-696
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• 2008

The purpose of this study was to evaluate the alkali-silica reactivity for aggregates in Korea according to test methods: accelerated mortar bar test (AMBT) by ASTM C 1260; chemical test by KS F 2545 (ASTM C 289). The results are as follows: The AMBT (ASTM C 1260) results showed that two (2) igneous rocks (two mica granite and felsite), three (3) sedimentary rocks (arkose, red sandstone and shale), two (2) metamorphic rock (slate and vitric tuff), one (1) mineral (quartz) showed more expansion than 0.1% at 14 days. But, some sedimentary rocks and metamorphic rocks expanded more than 0.1% at 28 days even though they were less than 0.1% at 14 days. Therefore, it is necessary to extend the experimental dates more than 14 days to evaluate the possibility of alkali-aggregate reactivity. The chemical test (KS F 2545) results showed that five (5) igneous rocks (andesite, diabase, granite porphyry, muscovite granite and diorite) were indicative of potentially deleterious expansion, while two (2) igneous rocks (diorite porphyry and quartz porphyry) were possible indicative of expansion, and three (3) igneous rocks (biotite granite, two mica granite and felsite) were indicative of innocuous reactivity. The above results showed that the results from chemical method (KS F 2545) and AMBT (ASTM C 1260) had little relationship.

• Journal of the Korea Concrete Institute
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• v.20 no.4
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• pp.431-437
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• 2008

The concrete pavement at Seohae Expressway in Korea has suffered from serious distress, only after four to seven years of construction. The deterioration of ASR has seldom been reported per se in Korea, because the aggregate used for the cement concrete has been considered safe against alkali-silica reaction so far. The purpose of this study is to examine the expansion behavior of aggregates of Korea due to alkali-silica reaction by ASTM C 1260 standard method of the accelerated mortar bar test (AMBT), stereo microscopic analysis, scanning electronic microscope (SEM) analysis, and electron dispersive X-ray spectrometer (EDX) analysis. The results are presented as it follows. The accelerated mortar bar test (AMBT) showed that mica granite and felsite of igneous rocks, aroke, red sandstone and shale of sedimentary rocks, slate of metamorphic rock, and dendrite and quartz of mineral rock showed more expansion than 0.1% at 14 days. But, some sedimentary rocks and metamorphic rocks expanded more than 0.1% at 28 days even though they were less than 0.1% at 14 days. The mortar bars, which showed more than occurred 0.1% expansion, resulted in cracking on surface. SEM and EDX analysis confirmed that the white gel was a typical reaction product of ASR. The ASR gel in Korea mainly consisted of Silicate (Si) and Potassium (K) from the cement. The crack in the concrete pavement was caused by ASR. It seems that Korea is no longer safe zone against alkali-silica reaction.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.837-843
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• 2010

This research investigated classification of clay activity degree by different clay mineral components. Based on compositions of different clay and oxide minerals within 390 soil series in Korea, 7 soils were selected to analyze for CEC and specific surface area of clay minerals. As a result, soils were mainly composed with Chlorite originated from sandstone, Smectite originated from Andesite porphyry and combination of Allophane and Ferrihydrite originated from volcanic ash, if the ratio of CEC value to clay content (degree of clay activity) was greater than 0.7. If the degree of clay activity was ranged between 0.3 and 0.7, soils were composed mainly with Kaolin originated from anorthite. Soils with this ratio also was composted with combinations of Kaolin, Illite and Vermiculite originated with river deposits. When the degree of the activity was less than 0.3, soils were commonly red-yellowish color and composed with two different minerals. One type of composition was Kaolin originated from granite and granite gneiss and the soils contained Geothite and Hematite. The other type was composited mainly with Illite and Vermiculite minerals originated from granite. These soils contained Gibbsite, Geothite and Hematite. The degree of clay activity was highly related with CEC and specific surface area. The greater degree of the activity displayed greater values of clay CEC and specific surface area. It is not easy to measure actual quantity and compositions of clay minerals, while the degree of clay activity can be measured from routine soil analyses. As a conclusion, the degree of clay activity may be not just a simple but also powerful tool to estimate physical-chemical properties of soils and to evaluate the soil classification in Korean soils.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.4
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• pp.1-14
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• 2017

In Korea, the soil series derived from sedimentary rocks are classified into seven soil series of coarse loamy soil such as Dain, Danbug, Dongam, Imdong, Jeomgog, Maryeong, and Yonggog; seventeen soil series of fine loamy soil such as Angye, Anmi, Banho, Bigog, Deoggog, Dogye, Dojeon, Gamgog, Gugog, Jincheon, Maji, Mungyeong, Oggye, Samam, Yanggog, Yeongwol, and Yulgog; six soil series of fine silty soil such as Goryeong, Bonggog, Juggog, Gyeongsan, Yuga, and Yugog; and four soil series of clayey soil such as Mitan, Pyeongan, Pyeongjeon, and Uji. All thirty-four soil series have different drainage rates and topography. However, the soil texture depends on the parent rock. The buffer functions in GIS (Geographic Information System) techniques were used to calculate adjacent soil series from a soil series. The length of the adjacent soil series was adjusted because a side of the buffer area was one meter long. The cluster analysis was conducted using the CCC (Cubic Clustering Criterion) method, in which the number of clusters is calculated based on the individual soil series ratio. Soil survey has been carried out since 1964 as "The reconnaissance soil survey", and 1:5,000 detailed soil survey was completed in 1999 with a five-years plan in Korea. Today, all the soil survey information has been computerized. GIS techniques were used to establish a digital soil map; however, there have not been any studies to interpret pedogenesis using the GIS technique. In this study, the area of the adjacent soil series were obtained using the GIS technique. The area of the adjacent soil series can be calculated based on the information area. The similarities of soil originated from sedimentary rocks were estimated using the length. As a result, the distribution of grain size was different based on the types of sedimentary rocks and the location. The clusters were distinguished into limestone, sandstone, and shale. In addition, the soil derived from shale was divided into red shale and gray shale. This means that quantitative interpretation of the catena and this established method can be used to interpret the relationship between soil series.