• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.236-237
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• 2014

Recently, it changes to the frame construction in the wall type structure for the life span improvement of the apartment house of our country. The execution of the light panel increased while the execution of the frame construction increased. Therefore, the density and absorption ratio of the magnesium oxide matrix according to the wood flour amount of addition ratio property try to be analyze for the lightweight of the surface material of the light panel. The test result, the density has been declined as the addition ratio increase of the wood flour. In the case of the water absorption ratio, water absorption ratio has been increased as addition ratio increase of wood flour. However, wood flour addition ratio 15% determined the most appropriate when considering the density and water absorption ratio.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.163-164
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• 2014

This study is conducted for prevent spread of penetration water and water leakage through non-woven fabric between PVC sheet and PVC sheet in the PVC composite waterproofing sheet of a multi-layer structure. For this, carry out absorption amount test to confirm spread resistance performance after manufacturing PVC composite waterproofing sheet of a multi-layer structure using water-repellency processed non-woven fabric. As a result of test, weight of water-repellency processed non-woven fabric increased to 1.178g, Compared with beginning and there are not penetration water.

• Advances in nano research
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• v.14 no.1
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• pp.81-92
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• 2023

In this work, the effect of the addition of Aerosil 200, an insulating resin applied in many industries, on the water absorption of cement plast mixture has been experimentally evaluated. First, the preparation stages of cement plast mixture was evaluated based on corresponding standards and then, the effect of the addition of Aerosil 200 nanoparticles (NPs) to cement plast mixtures with sand weight percentage range of 0-0.1% on the variation of water absorption properties was evaluated based on National Standard Institution of Iran 20185 for Concrete Flooring Blocks - Requirements and Test Procedures. Based on the obtained results, it could be found that excessive addition of NPs did not affect the physical properties of the final product. Water absorption percentage was increased in the weight percentage of cement. By the increase of the amount of Aerosil 200 NPs in the prepared cement plast mixture, the percentage of water absorption in weight percentage of sand was decreased. Cement plast with NPs presented significantly lower water absorption than that without NPs.

• Journal of the Korean Wood Science and Technology
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• v.37 no.1
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• pp.1-11
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• 2009

Although the exterior wood such as column may frequently contact with liquid water, little work has been found to measure liquid water absorption in wood. To investigate the moisture diffusivity of wood in the longitudinal direction including bound water and free water movement, liquid water absorption test was conducted at the room temperature. The order of magnitude for absorption coefficient and diffusivity was Japanese elm, horn beam, hemlock, spruce, radiata pine, and painted maple. The Boltzmann transformation method was used to determine the diffusivity from measured moisture content distributions in the absorption test. The shape of the curve representing the dependence of diffusivity with moisture content was similar in test samples. The diffusivity decreased with increasing moisture content until around the fiber saturation point and then increased at the nonhygroscopic region, which ranged from $10^{-10}$ to $10^{-7}m^2/s$.

• Corrosion Science and Technology
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• v.16 no.3
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• pp.141-150
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• 2017

Impregnating with quality silicone water repellent on the concrete surface is an effective method of protecting concrete. Quality silicone water repellent has been widely used in the engineering profession because of its desirable properties such as hydrophobicity, keeping concrete breathable and preserving the original appearance of the concrete. The companies in China that produce silicone water repellent are listed. Test methods in the specifications or standards about silicone water repellent in China are summed. The test methods relative to durability of concrete impregnated with silicone water repellent (such as resistant to chloride ion penetration, resistant to alkali, resistance to freezing and thawing and weatherability etc.) and the constructive quality (such as water absorption rate, impregnating depth and the dry velocity coefficient etc.) are compared and analyzed. The results indicate that there are differences among test methods relative to different specifications with the same index and therefore, confusion has ensued when selecting test methods. All test methods with the exception of the method of water absorption rate by using a Karsten flask are not non-destructive methods or conducted in a laboratory. Finally, further research on silicone water repellent during application is proposed.

• Advances in concrete construction
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• v.11 no.4
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• pp.323-333
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• 2021

The main objective of this study is to characterize and evaluate the hydrophobic performance of polymer-based water-repellent coatings on cementitious mortar surfaces. Different concentrations of poly(vinyl acetate) (PVAc) and poly(1,4-butylene adipate) (PBA) were prepared in the laboratory and their applicability and performance was tested experimentally by water absorption test and analysis of surface contact angles of cementitious mortar specimens. According to the results of this study, it can be stated that incorporation of nano polymer particles on the surface of cementitious mortar specimens can enhance contact angles and reduce water absorption by increasing hydrophobicity. However, a dosage limit exists for polymer materials in coating, and observed hydrophobic improvements decreases when polymer dosage reached beyond the limit. Additionally, it is observed that water absorption of polymer coated cementitious mortars is closely related with the results of surface contact angle.

• Korean Journal of Environmental Agriculture
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• v.41 no.1
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• pp.24-31
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• 2022

BACKGROUND: The most common litter materials used in South Korea are sawdust, rice husk, etc. Recently, the cost of litter has been steadily rising, and the maturity test has been strengthened. For this reason, new litter materials are needed for better water control ability to solve the problems. The object of this study was to evaluate the water absorption properties for litter materials. METHODS AND RESULTS: The volumetric water capacity according to the addition of cow manure was investigated to calculate the water absorption speed of litter materials (sawdust, peatmoss, cocopeat, and biochar). The water absorption speed constant (-K) in the first stage was high in the order of cocopeat (0.1190), sawdust (0.0961), biochar (0.0762), and peatmoss (0.0523). The optimal period of the litter use was in the following order: peatmoss (48d), biochar (42d), sawdust (30d), and cocopeat (24d). The water absorption rate (%) of the used litters was high in the order of biochar ≈ cocopeat, sawdust, and peatmoss, which was significantly correlated with the water absorption speed of the first stage. CONCLUSION(S): Considering the water absorption speed and water absorption rate, biochar and peatmoss were found to be the best and optimal litter materials among the tested materials. These litter materials can be used as water control agents in livestock facilities.

• Journal of the Korean Society of Costume
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• v.55 no.5 s.95
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• pp.101-107
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• 2005

In this article, mordant absorption rate by the Change of temperature and fabric, discharge level by water washing, mordant density and method in mordant dye are going to be handled. Besides, how treatment method will have an effect on absorption rate and color, is also going to be covered. An atom extinction photometer was used to measure the amount of mordant absorbed in fabric at each temperature and mordant type. It turned out that absorption rate differs according to the type of mordant and sample or temperature. Also it turned out that the mordant input amount has little influence on absorption rate, that is to say, if though you use more mordants, just tiny amount of mordant is going to be absorbed in cloth. It is true that the higher temperature goes up, the better mordant absorption gets. It is found that the type of mordant and sample, treatment period affects the discharge rate. Normally $15{\~}98\%$ mordant comes off the fabric by water washing, to be specific, $17{\~}47\%$ Iron by water washing and it has better performance on cotton and nylon than silk, $1\%{\~}52\%$ Aluminum by water washing and better absorption on silk, $36{\~}89\%$ Chrome by water washing and better absorption on silk, $50{\~}89\%$ copper by water washing and better absorption on silk, poor on cotton. The examination of the K/S values and colors between before and after soaping has been conducted under the circumstance that the test fabrics had been treated at $80^{\circ}C$ for 30 minutes with $0.2\%$ soaping solution. In case of pre-mordanted fabrics, the K/S value nosedived after soaping, meanwhile densely mordanted fabric's K/S value soared but after soaping, it dropped sharply. It turned out that soaping treatment deteriorates absorption much more than water washing. It's considered that $0.1 \%$ (W/V) of mordant density is appropriate.

• Journal of Korea Foresty Energy
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• v.21 no.2
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• pp.34-42
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• 2002

This research was carried out to investigate water repellent effectiveness of natural oil treated wood. Linseed oil, castor oil, olive oil, bean oil, perilla oil and sunflower oil were used in this test. For evaluation of water repellent of natural oil treated wood, moisture absorption test, water-drop contact angle test and color difference test of accelerated decomposition by UV and water were used. The moisture absorption amount of natural oil treated wood was less than untreated wood until 3 hours, but it was increased with time, there was no big difference with oil treated wood and untreated wood after 48hours. Oil treated wood and untreated wood showed big difference on contact angle test. It was no big difference by kind and oil concentration. Natural oil treated wood did not showed stability on the weather aging test. Contact angle test could be used on evaluation of wood surface status treated with natural oil.

• Journal of the Korean Society of Safety
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• v.37 no.4
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• pp.11-19
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• 2022

This paper presents the effects of high temperature and water absorption on the mechanical behaviors of carbon-aramid fiber composites, specifically their strength, elastic modulus, and fracture. These composites are used in industrial structures because of their high specific strength and toughness. Carbon fiber composites are vulnerable to the impact force of external objects despite their excellent properties. Aramid fibers have high elongation and impact absorption capabilities. Accordingly, a hybrid composite with the complementary properties and capabilities of carbon and aramid fibers is fabricated. However, the exposure of aramid fiber to water or heat typically deteriorates its mechanical properties. In view of this, tensile and flexural tests were conducted on a twill woven carbon-aramid fiber hybrid composite to investigate the effects of high temperature and water absorption. Moreover, a multiscale analysis of the stress behavior of the composite's microstructure was implemented. The results show that the elastic modulus of composites subjected to high temperature and water absorption treatments decreased by approximately 22% and 34%, respectively, compared with that of the composite under normal conditions. The crack behavior of the composites was well identified under the specimen conditions.