• Journal of the Korean Applied Science and Technology
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• v.31 no.2
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• pp.183-189
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• 2014

On the basis of our previous research results concerning a batch Teflon coating process on the surface of basalt fiber which has superior fire-resistance and chemical resistance, we have tried to set up suitable operating conditions for continuous polytetrafluoroethylene(PTFE) coating process. The basalt fiber was continuously pre-treated with 7.5 wt%(6.5% of DPU) of triethoxytrifluoropropylsilane(TMTFPS) and then coated with 20 wt% of PTFE dispersions containing 0.25 wt% of penetrating agent sodium bis(2-ethylhexyl)sulfo succinate (DOS-Na) to get the highest tensile and loop strengths. After dipping process, the PTFE coated basalt fiber was dried under 2 m drying chamber at $120^{\circ}C$ with 12 m/min of winding speed and consequently sintered under 2 m sintering chamber at $380^{\circ}C$ for 40 s. Conclusively, PTFE coated basalt fiber whose tensile and loop strengths were to $3.4g_f/D$ and $2.3g_f/D$, respectively, applicable to high temperature sewing thread could be continuously prepared with our pilot scale process under optimum conditions.

• Polymer(Korea)
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• v.39 no.2
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• pp.219-224
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• 2015

In this work, the effect of fiber array direction including $0^{\circ}$, $0^{\circ}/90^{\circ}$, $0^{\circ}/45^{\circ}/-45^{\circ}$ was investigated for mechanical properties of basalt fiber-reinforced composites. Mechanical properties of the composites were studied using interlaminar shear strength (ILSS) and critical stress intensity factor ($K_{IC}$) measurements. The cross-section morphologies of basalt fiber-reinforced epoxy composites were observed by scanning electron microscope (SEM). Also, the surface properties of basalt fibers were determined by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). From the results, it was observed that acid treated basalt fiber-reinforced composites showed significantly higher mechanical interfacial properties than those of untreated basalt fiber-reinforced composites. These results indicated that the hydroxyl functional groups of basalt fibers lead to the improvement of the mechanical interfacial properties of basalt fibers/epoxy composites in the all array direction.

• The Journal of the Petrological Society of Korea
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• v.25 no.3
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• pp.283-298
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• 2016

Sangumburi crater, designated as Natural Monument No. 63, recognized as a maar, but precise geological mapping and geological characteristics in the field indicate that Sangumburi crater is a pit crater. Two stages of volcanic activities created Sangumburi pit crater. Lava flow (aphanitic pyroxene basalt I) and associated pyroclastic deposit (pyroclast I), composed of ash and lapilli, were formed at the stage 1. In the stage 2, lava flow (feldspar olivine basalt) was overlain by lava flow (aphanitic pyroxene basalt II) and associated pyroclastic deposit (pyroclast II), composed of agglomerate. Sangumburi pit crater formed at $0.073{\pm}0.036Ma$, determined by Ar-Ar age dating for the feldspar olivine basalt at the stage 2. It is not clear the preferred migration direction of subsurface magma after Sangumburi pit crater formed.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.2
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• pp.111-120
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• 2024

This paper presents a study aimed at developing repair materials for emergency slope stabilization after disasters such as floods. The research assessed how different mix ratios of fly ash and reinforcement with basalt fibers affect the basic quality properties of mortars. Optimal amounts of fly ash were selected based on these properties, and appropriate amounts of chemical admixtures and thickeners were determined to enhance the quality attributed to the basalt fiber mixture. Notably, high-volume fly ash reduced the need for high-performance water reducers and improved workability, known benefits that also helped mitigate fiber ball issues in conjunction with the effects of thickeners. The experimental results indicated that the developed repair materials could potentially be used for emergency repairs, with a focus on initial age strength. This research aims to provide foundational data for repair materials used in future emergency slope stabilizations.

• Economic and Environmental Geology
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• v.35 no.6
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• pp.523-532
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• 2002

The rare earth elements (REE) and Nd, Sr and noble gas isotopic compositions eHer'He, 4$^{\circ}$Arp6Ar) for the Quaternary alkali basaltic rocks and mantle xenoliths in the basaltic rocks from the Baegryongdo were investigated to decipher the origin of alkali basaltic magma and xenolith beneath the Sino-Korean craton. Analytical results are summarized as follows; (1) The alkali volcanic rocks with voluminous xenoliths which are represented by the Mg-olivine and clinopyroxene dominant spinel-lherzolite in the Baegryongdo consist mainly of the basalt-mugearite and basaltic andesite. (2) The REE pattern of alkali basaltic rocks characterized by high HREE is similar to that of oceanic island basalt (OlB). Relatively concordant REE patterns of the basaltic rocks suggest that the alkali basaltic magma be formed by the identical source materials. (3) The Nd-Sr isotopic data of the alkali basaltic rocks suggest that the alkali basaltic magma be originated from the depleted mantle source with a little contamination of the continental crustal materials. (4) The $^3$He/ $^4$He ratios in olivines of xenoliths ranging from 5.0${\pm}$1.lRa to 6.7${\pm}$1.3Ra are lower than that of MORB (ca. 8.0Ra). It suggest that the xenolith be derived from the subcontinental lithospheric mantle. However, the high $^3$Her'He value of 16.8${\pm}$3.IRa at 1800$^{\circ}$C fraction (sample no OL-7) might be resulted from the post-eruptive cosmogenic $^3$He. The 4OAr/ 36 Ar ratios in olivines of mantle xenoliths are comparable to that of atmospheric argon, and are much lower than that of the MORB type mantle. These facts can lead to conclusion that the olivine of the xenolith in the Baegryongdo is affected by the post-eruptive atmospheric contamination during the slow degassing process.

• The Journal of the Petrological Society of Korea
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• v.17 no.2
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• pp.108-131
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• 2008

The Miocene andesite and basalt intruded into and/or extruded on the Cretaceous volcanic and granitic rocks over the area of Chenjabong and Sirubong in the vicinity of Jinhae, southern part of Kyongsang basin. The K-Ar ages of the younger volcanic rocks are from 16 Ma (Sirubong andesite) to 10 Ma (Cheonjabong basalt), which indicate the Miocene volcanism in the outer part of the Tertiary basin in the Korean peninsula. The volcanics are divided into Chenjabong andesite, Cheonjabong basaltic andesite, Sirubong andesite and Cheonjabong basalt. The Cheonjabong andesite is composed of phenocrysts of clinopyroxene and plagioclase ($An_{60{\sim}64}$) and groundmass with lath-like plagioclase ($An_{76{\sim}84}$) and glass. The Cheonjabong basaltic andesite is composed of plagioclase phenocryst ($An_{60{\sim}64}$) with plagioclase lath ($An_{65}$) and glass in groundmass. The Sirubong andesite is only consisted of plagiocalse lath ($An_{64{\sim}68}$) and glass with absence of phonocryst. The Cheonjabong basalt shows typical porphyritic texture with phenocrysts of olivine ($Fo_{69-84}$) and clinopyroxene. The groundmass of the Cheonjabong basalt is composed of microphenocrysts of olivine, clinopyroxene and plagioclase ($An_{66{\sim}71}$) and plagioclase laths ($An_{57{\sim}65}$) showing pillotaxitic and intergranular texture. The Cheonjabong andesite, Cheonjabong basaltic andesite, Sirubong andesite are belong to calc-alkialine but the Cheonjabong basalt is alkaline basalt. By tectonic discrimination diagrams the parental magmas of the volcanic rocks have occurred boundary.

• Journal of Environmental Impact Assessment
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• v.25 no.3
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• pp.209-221
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• 2016

The section from water source to 2.6km upper stream of Hantan River is protected as the drinking water quality protection area according to guidelines of Ministry of Environment, because water source of the Gwanin water intake plant has been known the river. However, opinions were consistently brought up that the standard of water source protection zone must be changed with using underground water as water source because of contribution possibility of underground water as the water source of Gwanin water intake facility. In this regard, hydrogeologic investigation including resistivity survey and hydrogeochemical investigation were carried out to assess water source and infiltration of contaminant for the plant. Quaternary basaltic rocks (50m thick with four layers) covered most of the study area on the granite basement. As the result of the resistivity survey, it is revealed that permeable aquifer is distributed in the boundary of two layers: the basaltic layer with low resistivity; and the granite with high resistivity. Considering of outflow from Gwanin water intake facility, the area possessing underground water was estimated at least $5.7km^2$. The underground water recharged from Cheorwon plain was presumed to outflow along the surface of unconformity plane of basalt and granite. Based on field parameters and major dissolved constituents, groundwater and river water clearly distinguished and the spring water was similar to groundwater from the basaltic aquifer. Temporal variation of $SiO_2$, Mg, $NO_3$, and $SO_4$ concentrations indicated that spring water and nearby groundwater were originated from the basaltic aquifer and other groundwater from granitic aquifer. In conclusion, the spring of the Gwanin water intake plant was distinguished from river water in terms of hydrogeochemical characteristics and mainly contributed from the basaltic aquifer.

• Explosives and Blasting
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• v.29 no.2
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• pp.89-99
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• 2011

Recently on Jeju island there has been a lot of development and construction. However random distribution of porous basalt and clinker seam generated from volcanic activities often interrupt and greatly reduce efficiency of blasting necessary for construction. Three test blasts were operated to solve the inefficiency problem and results indicated that a powder factor of 0.40~0.45 $kg/cm^3$ is necessary to increase the efficiency of blasting. Also the blasting scheme should be concerned whether clinker seams exists in excavation levels or not.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.3
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• pp.127-133
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• 2003

The effect of parent rocks to the soil microbial diversity were investigated in soils developed from granite, limestone and basalt parent rocks. In the soils, microbial populations were positively related to the soil chemicals, such as soil pH with ftuorescent Pseudomonas, and soil EC with actinomycetes, fungi, mesophilic Bacillus and alkaliphilic bacteria. Gram negative bacteria, spore forming Bacillus, were maintained relatively same levels of population between granite, limestone and basalt soils. Among the species of Burkholderia, Pseudomonas and Ralstonia were dominated in the granite soils, Pseudomonas, Burkholderia and Phyllobacterium in the limestone soils, and Burkholderia in the basalt soils.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.09a
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• pp.55-71
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• 2005

Jeju Island is mainly composed of basaltic lava flows and subordinate amounts of volcaniclastic sedimentary rocks. Jeju Province operates the monitoring wells for seawater intrusion problems around Jeju Island to evaluate of groundwater resources in coastal area. Various surveys and monitoring have been performed in boreholes, and also conventional geophysical well loggings conducted to identify basalt sequences and assess seawater intrusion problems. Various conventional geophysical well logs, including radioactive logs, electrical log, caliper log, and temperature and conductivity log and heat-pulse flowmeter log were obtained in 29 boreholes. The results of geophysical well loggings for saturated rocks are interesting and consistent. Natural gamma logs are useful in basalt sequences to sedimentary interbeds, unconsolidated U formation, and seoguipo formation with higher natural gamma log regardless of saturated or unsaturated basalts. Neutron logs are very effective to discriminate among individual lava flows, flow breaks, and sedimentary interbeds in saturated formation. In hyalocastite, porosity is high and resistivity is low, and we think that hyalocastite is a major pathway of fluid flow. In trachybasalt, porosity has a wide range and resistivity is high. In sedimentary interbeds, unconsolidated U formation and seoguipo formation, porosity is high and resistivity is low. The temperature logs in eastern area in Jeju are useful to interpret the hydrogeological unit and evaluate seawater intrusion in Suan area.