• Journal of Korean Tunnelling and Underground Space Association
• /
• v.5 no.4
• /
• pp.361-370
• /
• 2003

In this study, the performance of water tightness of water expansional sealing material and gasket was evaluated. The water tightness test was performed varying the type of inner pressure condition, for which the water expansional sealing material was inundated for 5 days to evaluate the ability of water tightness. In order to carry out this test, we made use of two types of water expansional sealing material; general type and combined type with non-expansional rubber. In the case of gasket, EPDM gasket and complex gasket sticked to the water expansional sealing material were applied. The performance of water tightness depended on the construction defect and the deformation of segment. The construction defect and segment deformation were generally expressed by gap and offset of the construction joint. The results, of tests showed that the performance of water tightness was largely influenced by the gap between segments. Management criteria of gap and offset were proposed.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.11a
• /
• pp.529-532
• /
• 2008

The durability of concrete and the water-tightness properties of cementitous material are closely relation. So, water-tightness materials as natural minerals, organic fatty acid, organic fatty salts inorganic materials use for improvement of concrete durability. But these materials are somehow different in water-tightness mechanism. In this study, we studied on hydration properties and water-tightness properties of cementitous materials with zinc-stearate, a kind of organic fatty acid salts.

• Fashion & Textile Research Journal
• /
• v.20 no.4
• /
• pp.457-463
• /
• 2018

This study examined the water absorption and drying properties of the thirteen types of the knitted fabrics for sports wear. These physical properties were analysed with relation to the constituent fiber cross-sectional shape and structure parameters of the knitted fabrics by regression analysis. Absorption and drying properties of the knitted fabric specimens were increased with increasing the porosity of the constituent yarns, which was attributed to the capillary channels in the yarns. The water absorption and drying properties were increased and decreased with increasing tightness factor and stitch density of the knitted fabric. The absorption property of the knitted fabric for perspiration absorption and fast dry sport-wear clothing was mostly influenced mostly by fiber cross-sectional shape and its characteristics, whereas, drying property was dependent on the structural parameters of the knitted fabric such as tightness factor and stitch density. Therefore, superior perspiration absorption and fast drying knitted fabric could be obtained in the fabric structure with optimum tightness factor and stitch density, and constituent yarn structure with non-circular fiber crosssection and high porosity. GATS method and MMT method are used to measure sweating fast drying properties and it is necessary to carry out studies using these measurement methods in order to compare with the results of this study.

• Journal of Ocean Engineering and Technology
• /
• v.22 no.4
• /
• pp.40-45
• /
• 2008

This paper describes the effects of fly ash replacement on the water tightness of antiwashout underwater concrete, which replaced the cement with fly ash from 0% to 30%. The experimental work was performed to find out the depth of permeation of concrete specimens cast in air and cured in 23 $^{\circ}C$ tap water using an open center pressure type of water permeation tester. The results showed that the permeation depth values of antiwashout underwater concrete were deeper than normal concrete, but that an admixture using fly ash during antiwashout underwater concrete casting in air made it more watertight than normal concrete according to the water permeation testing. SEM observations of the specimens of fly ash antiwashout underwater concrete showed that it wasmore packed with structures because of the pozzolan reaction of the fly ash and cement.

• 한국태양에너지학회:학술대회논문집
• /
• 2008.04a
• /
• pp.330-335
• /
• 2008

This research aims to investigate the standards and the performances of domestic and foreign windows for and apartment house and to present fundamental data for selecting the optimum window at the step of designing an apartment house. To compare the performances of domestic and foreign windows it is selected 5 major window companies in and 3 major window companies in Japan, and investigated window structure, material, type of opening and closing, window glass and the performances of windows for an apartment house-closing and opening force, repeated closing and opening, thermal resistance, sound transmission loss, air tightness, water tightness, wind resistance. The result of a comparative analysis show that the average thermal resistance of Korean window is higher than Japan's but the average sound transmission loss and water tightness of Korean window is lower than Japan's and the rest of the performances is similar.

• Journal of the Korean Ceramic Society
• /
• v.27 no.7
• /
• pp.833-840
• /
• 1990

For the development of multi-functional materials which has water reducing power, air entraining power and waterproofing power as well as blending additive in cement mortar the coal ash was modified with asphalt-stearic acid or asphalt-boiled oil mixtures by mechanical treatment. And the physical properties of cement mortar blended with modified coal ashes were compared with those of the water-tightness-cement mortar and the ordinary-portland-cement mortar added with AE.water reducing agent. The mortar of coalash-blend-cement modified with asphalt-stearic mixture was increased acid about 20% in initial strengths and decreased about 20% in water absorption ratio than those of ordinary coalash-blend-cement. The mortar of coalash-blend-cement modified with asphalt-bolied oil mixture was similar to the cement mortar added with AE.water reducing agent in water reduction ratio, air entraining conents and the initial strengths, also was similar to the water-tightness-cement mortar in water absorption and water permeability ratios.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2000.11a
• /
• pp.705-712
• /
• 2000

The fluid generally flows through fractures in crystalline rocks where most of underground storage facilities are constructed because of their low hydraulic conductivities. The fractured rock is better to be conceptualized with a discrete fracture concept, rather continuum approach. In the aspect of fluid flow in underground, the simultaneous flow of groundwater and gas should be considered in the cases of generation and leakage of gas in nuclear waste disposal facilities, air sparging process and soil vapor extraction for eliminating contaminants in soil or rock pore, and pneumatic fracturing for the improvement of permeability of rock mass. For the purpose of appropriate analysis of groundwater-gas flow, this study presents an unsteady-state multi-phase FEM fracture network simulator. Numerical simulation has been also conducted to investigate the hydraulic head distribution and air tightness around Ulsan LPG storage cavern. The recorded hydraulic head at the observation well Y was -5 to -10 m. From the results obtained by the developed model, it shows that the discrete fracture model yielded hydraulic head of -10 m, whereas great discrepancy with the field data was observed in the case of equivalent continuum modeling. The air tightness of individual fractures around cavern was examined according to two different operating pressures and as a result, only several numbers of fractures neighboring the cavern did not satisfy the criteria of air tightness at 882 kPa of cavern pressure. In the meantime, when operating pressure is 710.5 kPa, the most areas did not satisfy air tightness criteria. Finally, in the case of gas leaking from cavern to the surrounding rocks, the resulted hydraulic head and flowing pattern was changed and, therefore, gas was leaked out from the cavern ceiling and groundwater was flowed into the cavern through the walls.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.2 no.4
• /
• pp.33-38
• /
• 1982

A successful operation of underground oil storage cavern depends on water-tightness around cavern by groundwater. If water-tightness is not secured, gas bubbles would leak out and oil would migrate to an adjacent empty cavern. In this research an electrical analogy method was employed to study the influence of shape of cavern on gas leakage and the required natural groundwater level, relative oil level in two neighboring caverns and cavern spacing to prevent oil migration. The results show that gas leakage is prevented from a cavern with a ceiling of large curvature. The required values of factors to curtail the migration of oil are given on a graph.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.11a
• /
• pp.817-820
• /
• 2004

Our country was much developments in change of construction environment along with fast economy development. But, various problems that must think in problem of safety and quality were appeared. Constructions which build through rapid economy development are getting many social criticisms to problem of crack and water leakage at use process. Is situation that huge repair expense to cure this is engaged. Safety problem of construction is indicated socially through various media mediums again.

• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.35 no.9
• /
• pp.199-206
• /
• 2019

Experimental study on the durability characteristics to examine the feasibility of concrete with high water-tightness and self-healing performance to minimize maintenance of concrete for artificial ground is as follows. 1) When blending agent, swelling agents, and curing accelerator were added on the ternary system cement with blast-furnace slag fine particles and fly ash to give a self-healing property, higher blending strengths by 82% at design standard strength of 24MPa and by 74% at design strength of 30MPa, respectively could be obtained. 2) The permeability test for the specimens having high water-tightness and no shrinkage showed that the permeability was reduced at maximum of 98%. However, the permeability was decreased as the design strength was increased, showing the reduction rate of 87% at the design strength of 50MPa. 3) The depth of carbonation of blast-furnace slag and fly ash was increased in all the specimens compared with those of OPC only. However, as the material age was increased, carbonation penetration depth was decreased compared with the reference blend. 4) Compared with the reference blending using only OPC, the freeze-thaw resistance was higher in the case of blending with 40% of blast-furnace slag and 10% of fly ash at the design standard strength of 50MPa. In addition, the freeze-thaw resistance in general was superior in the design standard strength of 50MPa with the lower water-binder ratio (W/B) as compared with the design standard strength of 24MPa and 30MPa with the high water-binder ratios.