• 한국가구학회지
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• 제24권3호
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• pp.257-262
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• 2013

This study was carried out to investigate the susceptibility of wood-based composite panels exposed to mould and sap-stain fungi. Five wood deterioration fungi (three mould fungi, two sap stain fungi) were inoculated into two types of commercial wood-based composite panels (medium density fiberboard and particleboard), which have three class of formaldehyde emission. All wood-based composite panels were more or less susceptible to mould and sap stain fungi. The attacking mode of the fungi was highly dependent on formaldehyde emission. This study indicates that all wood-based composite panels, specially low formaldehyde emission class panels should be considered to prevent fungal deterioration when they are used for exterior and humid interior applications.

• Journal of the Korean Wood Science and Technology
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• 제25권3호
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• pp.96-104
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• 1997

The objective of this research project was to develop the wooden footpath block to reuse of wood waste. Some physical and mechanical properties of the wooden block such as water absorption, thickness swelling, modulus of rupture, internal bond, density profile and impact resistance were studied. Water absorption and thickness swelling of the wooden block were greatly reduced when the wooden block was pressed inside the forming device than by conventional hot pressing. Also, Modulus of rupture and internal bond of the wooden block were increased greatly when the pressing was completed inside the forming device. The density profile of the wooden block was improved up to 93.5%, minimum to average density ratio. The wooden block manufactured in this study have excellent physical and mechanical prperties in comparison with existing wood based materials. So, these wooden blocks are applicable to footpth block or other exterior members.

• Journal of the Korean Wood Science and Technology
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• 제22권1호
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• pp.20-27
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• 1994

Water repellent preservative (WRP) treated and untreated, small-sized specimens prepared from semiwater resistant, water resistant, and tegofilm-overlaid plywood were exposed to outdoor weathering for one year. Exterior durability of specimens was evaluated on the basis of changes in dynamic modulus of elasticity, degree of delamination, modulus of elasticity, modulus of rupture, and glueline shear strength. Among untreated specimens, tegofilm-overlaid plywood showed the best outdoor durability, and durability between semiwater resistant and water resistant plywood was similar. Although WRP treatment increased the durability of all types of plywoods, the effect of treatment on the increase in durability for semi water resistant plywood was not distinct. Accordingly, it can be concluded that semi water resistant plywood, which is used for temporary construction such as concrete formwork in our country, can not be inadequate for exterior use, regardless of WRP treatment. The bending strength and glueline shear strength of untreated water resistant plywood measured after weathering for one year did not exceed the minimum value specified by Korean Standard (KS), thereby the outdoor use of water resistant plywood was not desirable without WRP treatment. Exterior durability between treated water resistant plywood and untreated tegofilm-overlaid plywood was very similar. This result suggests that if an exposed plywood surface is treated with WRP regularly water resistant plywood can be used for temporary construction. This suggestion, however, needs to be investigated. In summary, semiwater resistant plywood cannot be used for temporay construction regardless of WRP treatment. Water resistant plywood can be used only with WRP treatment. Comparing the cost of tegofilm-overlaid plywood to costs of water resistant plywood and WRP treatment, however, it can be concluded that use of tegofilm-overlaid plywood for temporay constrution is strongly suggested from the point of view of both outdoor durability and costs.

• Journal of the Korean Wood Science and Technology
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• 제39권6호
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• pp.531-537
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• 2011

본 연구는 지상부 사용조건에서 야외에 노출된 목재의 부후위험을 평가하기 위하여 수행되었다. 국내 72개 장소에서 10년 동안 축적된 기후자료를 활용하여 Scheffer 지수가 계산되었으며, 이에 근거하여 목재부후위험지도가 작성되었다. 제주, 서귀포, 광주, 전주 지역의 Scheffer 지수가 65 이상으로 부후위험이 높은 지역에 속하는 것으로 나타났으며, 이 지역을 제외한 나머지 지역은 Scheffer 지수가 35에서 65 사이의 값을 보여 부후위험이 중간 정도인 것으로 판명되었다. 그러나 기후조건에 따른 Scheffer 지수의 편차가 크기 때문에 부후위험이 중간정도로 판단된 지역이 기후변화에 따라 부후위험이 높은 지역으로 변할 수 있는 가능성이 높은 것으로 보인다. 특히 최근의 국내 기후가 아열대성으로 변화하는 경향을 고려할 때 국내 부후위험은 점차적으로 증가할 것으로 판단된다.

• 한국가구학회지
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• 제18권4호
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• pp.275-281
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• 2007

This study was carried out to know bending process property of bentwood by treatment methods such as microwave and ammonia solution treatment. Bentwood processing was operated on bending-jig form with 60mm and 100mm radius of curvature (ROC). The species was used to Korean red pine (Pinus densiflora). No significant difference was shown in bentwood processing method on ROC. In treatment method, ammonia solution treatment for bentwood was better in dimensional stability and working ability than that of microwave treatment. However, bentwood stress was reduced with ammonia solution treatment. Color of bentwood surface appearance has a dark tendency in ammonia solution treatment. But it seems to beautiful effect of apparent annual ring is rising esthetically by ammonia solution treatment. To utilize wood as a exterior material for living amenity, it has to be closely examined from various angles including surface property, degree of swelling and shrinkage, drying state, retaining strength, durability, safety, and insect damage.

• Journal of the Korean Wood Science and Technology
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• 제27권4호
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• pp.43-50
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• 1999

The safety-evaluation of ancient wood structures has been executed with only visual inspection. The application of NDE(nondestructive evaluation) is required because the visual inspection has many restrictions. Among many NDE techniques, the stress wave technique was used in this research. This study focused on evaluating the extent of decay in members of ancient structures, using stress wave nondestructive technique. For application of stress wave technique to ancient structures, the threshold time which divides members into categories according to degree of decay should be determined in advance. Stress wave timer (Metriguard Model 239A) was used in this study, specimens used in this research were the members obtained from six ancient structures. All specimens were identified as Hard Pine(Pinus densiflora S. et Z. or Pinus thunbergii P.) by microscope. Each member was tested with stress wave passing radially through the pith. In this study, the stress wave time of $12{\mu}s$/cm could distinguish between sound and decayed specimens with accuracy of 77.5 percent. Also, decayed specimens could be separated into moderate and severe categories by stress wave time of $20{\mu}s$/cm. Among the three decay location groups (exterior, mixed, interior), the exterior group could be classified into sound, moderate and severe decay with the greatest accuracy. Stress wave transit time was not sensitive to small decay pockets located in interior of the member.

• Journal of the Korean Wood Science and Technology
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• 제26권1호
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• pp.70-75
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• 1998

In this paper, the relationships between volumetric mixing ratio of rubber chip and physical and mechanical properties of wood/rubber composite panel was examined in order to investigate the mixture characteristics of wood and rubber chip. Because of the specific gravity of rubber differed from wood chip, physical properties of wood/rubber composite panel was shown very different values by mixing rate of chip element. Specific gravity in air-dry of composite panel was increased rapidly as volumetric percent of rubber chip was increased. Moisture content of composite panel was decreased as volumetric percent of rubber chip element was increased. This results was considered that wood weight is light and porosity material for moisture absorption. Compressive strength and modulus of rupture in bending test were decreased as volumetric percent of rubber chip increased. By mixing ratio control of chip elements, various wood/rubber composite panel can be applicable to every interior materials such as subfloor, playground, and exterior materials such as road blocks for recreational facilities in garden and forest and city parks.

• 한국가구학회지
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• 제24권3호
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• pp.302-308
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• 2013

To collection of field data for development of maintenance manual of Han-ok, we investigated defects which occurred in members of Han-ok by field investigation. The noticeable defects were wood cracks, gaps that developed between wood pillar and wall or wood window frame and tenon joints. The most common biological defect was blue stain which was created in log. The mold generation was observed on exterior wood and wall which get wet by precipitation. The gaps between members of Han-ok pointed out as defect that is urgently improved by residents of Han-ok. The reason is mainly due to poor of insulation in winter by bad confidentiality. The maintenance work of defect such as gap was conducted personally. As a result, the repair parts were ugly for unfamiliar repair work.

• 한국환경복원기술학회지
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• 제18권6호
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• pp.227-237
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• 2015

From January 2013 to October 2015, weed invasion control techniques was tested in the test road of Jungbunaeryuk expressway so as to collect preliminary data for the management methods of the upper exterior banking of expressway shoulders. Then, monitoring was conducted and its results are as follows. Mat (sheet), solidifying agent, and mulching (wood chips) were applied for the test and their initial effects of preventing weed invasion were all excellent. It was found that the homogeneity of the wood chip mulching method needs to improve. In the mat method and the mulching method were found to have the most excellent economic feasibility and aesthetics, respectively. The covering degree was found to be the highest at 80% in the control site, followed by the wood chip site at 20% and the solidifying agent site and the non-woven fabric site at 5% each. As for species diversity, the control had the largest variety of species. Two years after the construction, many different species of plants invaded and were growing. Plants including weed didn't tend to invade the slopes applied with non-woven fabric. In addition, weed didn't invade the solidifying agent site and the aesthetics of the upper exterior banking of expressway shoulders was found to be excellent. The wood chip site was found to require consistent management for preventing weed invasion. The mat (sheet) site, the solidifying agent site, and the wood chip mulching site were found to have excellent weed prevention effects. As time passed, the mat (sheet) site and the solidifying agent site showed better weed prevention effects. However, they need consistent monitoring for further application.

• Journal of the Korean Wood Science and Technology
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• 제44권1호
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• pp.75-84
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• 2016

건물에너지 저감에 효과적으로 기여하는 건축 재료를 이용하는 목조주택을 기반으로 단열 성능이 향상되고 있다. 그러나 고단열 고기밀화로 인한 습기 제어가 어려워져 외벽의 결로 및 곰팡이 발생으로 인하여 성능이 저하될 수 있다. 이에 열 습기 시뮬레이션 프로그램을 이용하여 선정한 5가지 형태의 목조주택 외벽의 열 습기 성능, 결로 발생 및 곰팡이 성장 위험을 평가하였다. 목조주택은 농촌주택 표준설계도 '10과 '14, $2^{{\prime}{\prime}}{\times}6^{{\prime}{\prime}}$형, EIFS 그리고 목조형 패시브 하우스로 선정하였고, 각 벽체 레이어를 구성에 따라 벽 A, B, C, D, E로 구분하였다. 벽체의 열관류율은 각각 0.171, 0.172, 0.221, 0.150, $0.079W/m^2K$이다. 벽 A와 C의 OSB 절대함수량은 기준치 20%를 초과하는 값이 나타났고, 결로 평가를 통하여 단열재 내부 표면에서 겨울철에 결로가 발생할 수 있음을 확인하였다. 벽 D와 E는 외단열 벽체로 다른 벽체에 비하여 함수량 평가와 결로 평가에서 우수한 결과를 보여주었다. 그러나 곰팡이 성장 위험 평가에서 5가지 형태의 벽체 모두 곰팡이 성장 위험성이 있음을 확인하였다. 이에 따라 외벽의 열 습기 성능의 차이는 열적 성능에 의한 발생보다는 레이어 구성에 따른 차이가 발생하는 것으로 판단되었다. 모든 벽체는 비슷한 열적 성능을 가지고 있으나 레이어에 따라 동일한 조건에서의 적합성이 다르게 나타나는 것을 확인하였다.