• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.1-12
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• 2007

For the purpose of effective utilization of domestic second-grown larch as structural members, post and beam construction applying traditional construction to Japanese larch glulam members was adopted with processing by machine pre-cut method. In general, horizontal shear test by KS F 2154 is conducted to assess the horizontal shear properties of the wooden structure by post and beam construction. The frame was consisted of post and beam member with appropriate fasteners, and members have their own processed parts (notch, hole, etc.) that can be well-connected each other. The shear wall was consisted of the frame with screw-nail sheathed panel (OSB). The results of horizontal shear loading tests without vertical loads conducted on the frame and the shear wall structures, the maximum strengths were about 1.9 kN/m and about 9.7 kN/m, the shear rigidities were about 167 kN/rad, 8198 kN/rad, respectively. The strength proportion of the frame specimen was about 20% of the wall's and about 2% in initial stiffness. Nail failures are remarkable on the shear wall specimen with punching shears and shear failures. The shear load factor for the shear wall specimen by the method of Architectural Institute of Japan was 1.5, which was obtained by the bi-linear method. Loading method should be considered to obtain smooth load-deformation relationship. For the better shear performance of the structures, column base and post and beam connections and sheathed panel should be further examined as well.

• Journal of the Korean Wood Science and Technology
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• v.39 no.1
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• pp.8-14
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• 2011

Japanese larch glulam was used as structural members to develop a modern engineered wood jointing system using traditional post and beam structure. For the connections comprised of traditional joining and drift-pins, structural members are processed at a pre-cut factory. As a basic study to examine and increase the whole shear performance of portal frame, pin withdrawal test and moment resistance tests were conducted on each connection. The post and beam members with specified connectors showed good bearing performance in the wood members' joining system, column-base and beam-end. Moment rigidity was a bit better in a joint with higher slenderness ratio of drift-pin, but moment resistance performances, yield moment and maximum moment, were excellent in smaller one.

• Journal of the Korean Wood Science and Technology
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• v.23 no.3
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• pp.48-57
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• 1995

본 연구에서는 경골 목조 주택 (2${\times}$4 주택, 2${\times}$6 주택), 통나무 주택 및 콘크리트 주택(내단열, 중단열, 외단열) 벽체에 대하여 유한 요소 해석으로 단열 성능을 평가하였고, 표면 결로 현상을 분석하여 다음과 같은 결론을 얻었다. 1. 벽체의 단열 성능은 정량 골조 2${\times}$6를 사용한 주택이 가장 우수하였고, 경량 골조 2${\times}$4 주택, 통나무 주택, 콘크리트 주택의 순으로 감소하는 것으로 나타났다. 2. 콘크리트 벽체의 내단열, 중단열, 외단열의 벽체 구성법에 따른 단열 성능의 차이는 없었으며, 콘크리트 주택에서 단열재의 사용이 필수적이었다. 3. 내부 결로의 경우 콘크리트 벽체의 외단열이 가장 우수한 결로 예방성을 보였다. 이는 외부에 설치된 단열층이 외부의 낮은 온도를 차단해 벽체 전체의 온도를 높게 유지하기 때문이었다. 표면 결로는 모든 벽체에서 나타나지 않았지만, 실내 습도가 높아진다면 콘크리트 주택의 벽체에서 발생할 가능성이 가장 높았다. 본 연구는 벽체내의 단열 성능에 관하여만 분석을 하였고, 열전달 외에 축열성능 등에 관한 고려는 하지 않았으므로 추후에는 여러 가지 복합적인 열적 성능에 관한 연구가 수행되어야 하리라고 생각한다.

• Journal of the Korean Wood Science and Technology
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• v.20 no.1
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• pp.46-50
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• 1992

본 연구는 잣나무 간벌재를 이용한 plywood gusset plate 접합과 toothed metal plate 접합에 대하여 인장력을 가해 조사하였다. plywood gusset plate 접합에 있어서는 합판과 부재 사이를 상온 경화제(초산 비닐 수지)로 접착한 후 6d 못으로 접합한 형태와 단지 합판만을 사용한 형태의 plywood gusset plate 접합 사이의 기계적 특성 차이를 조사했다. toothed metal plate 접합은 plywood gusset plate 접합보다 인장력에서 좋은 behavior를 보였다. 또한 접착제를 가한 plywood gusset plate 접합은 접합제를 가하지 않은 형태보다 큰 하중 지지력을 보였다.

• Journal of Korean Society of Forest Science
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• v.98 no.2
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• pp.203-211
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• 2009

The study was conducted to examine consumers' awareness and perceptions on forest certification and their willingness to buy and pay price premium for certified wood products especially for selected four wood products. A total of 136 residents in Seoul and Gyeonggi Province were interviewed in the autumn of 2008. Although only 24.3 percent of the consumers are aware of forest certification, 82.4 percent of the respondents recognized the need and significance of forest certification. In general, 77.2 percent of the respondents were willing to buy certified wood products. Majority of the respondents, 84 out of 136 respondents (61.8%) expressed their willingness to pay (WTP) from more than 0 percent to less than 10 percent. Consumers' average WTP for certified wood products was estimated to be 5.6 percent. From the results of the study, lower priced wood products, such as copier paper (WTP=9.8%) and wood frame (WTP=11.6%), have higher price premiums than high priced products, such as wood table (WTP=6.8%) and wood flooring (WTP=7.6%). In conclusion, there could be feasible markets for certified wood products in South Korea as four out of five consumer are willing to pay more for such products. For the forest certification system to be adopted and widely accepted, the perceptions of forest stakeholders including consumers should be further increased.

• Journal of the Korean Wood Science and Technology
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• v.36 no.4
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• pp.66-76
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• 2008

Recently, demands for the structural uses with domestic Japanese larch and SPF(spruce-pine-fir) lumber from North America have been increased. Shear properties of nailed joints that are the most simple and optimum fastening method in wooden constructions, especially in light frame construction. For the nailed joints, in North America and Japan, a number of basic and practical studies have been performed. The shear behaviors for the double nailed joint with variations of member and its direction, were examined. Shear properties of the shear specimens with SPF stud showed more remarkable variation than larch glulam and larch stud. Furthermore, the relationships between slip modulus and strength are not coincided in every case.

• Journal of the Korean Wood Science and Technology
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• v.47 no.4
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• pp.533-542
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• 2019

As energy costs increase, more people has become interested on energy efficiency and savings in residential buildings. The two main subjects related to energy in residential buildings are insulation and condensation. There are two approaches to prevent condensation; increasing air tightness and maintaining the temperature inside of the wall structure over the dew point, which is in turn related to insulation. Even though the Korean government has highlighted the importance of energy efficiency for residential housings, and in spite of the customers' demands, the timber construction industry is still using conventional light-frame construction without even trying to improve energy efficiency. In this study, various types and combinations of wall structures were tested under cold outdoor and warm indoor temperatures to analyse the temperature gradients and to determine the possible sites of condensation in the wall structures. In addition to the experimental tests, three theoretical models were developed and their estimations of temperature change through the wall structure were compared with the actual measurements to evaluate accuracy of the models. The results of the three models agree relatively well with the experimental values, indicating that they can be used to estimate temperature changes in wall structures. The theoretical analysis of different insulation layers' combinations show that condensation may occur within the mid-layer in the conventional light-frame wall structures for any combination of inner-, mid-, and outer-layers of insulation. Therefore, it can be concluded that the addition of an inner and outer insulation layer or increasing the thickness of insulation may not be adequate to prevent condensation in the wall structure without preventing penetration of warm moist air into the wall structure.

• Journal of the Korean Wood Science and Technology
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• v.42 no.2
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• pp.193-206
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• 2014

Residual performance of old architectural wood which has been damaged was measured using Nondestructive Evaluation (NDE). The wood Pole Tester was used to assess ultrasonic velocity inside wood and drill resistance was determined using an IML-resistograph. For ultrasonic measurements squared timber and circular timber's measurements were separately conducted with 1,300 m/s as the standard ultrasonic velocity. The standard wood samples divided into two parts; a non-sound area (below the standard), and a sound area (above the standard). Furthermore, schematization of wood was compared with results naked eye observation. The drilling resistance test was performed for both length and thickness direction in wood. The internal of the drilling was set at 30 cm (length direction), 5 cm (width direction) and 30cm (thickness direction). A non-sound area was defined as that 1) amplitude is below 20% and 2) carbonization and deterioration are related.

• Journal of the Korean Wood Science and Technology
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• v.18 no.2
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• pp.8-15
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• 1990

This study was carried out to investigate the wood qualities for the end-use development of sycamore (Platanus occidentalis L.) grown in Korea. The results obtained were as follows: 1. The average length of wood fibers was l.56mm and the average width of annual rings was 9.5mm. It had very fast growth rate. 2. The specific gravity in air-dry was 0.66. The shrinkage and water absorption were relatively large. The shear and impact strengthes were very strong, while the compressive, tensile, and bending strengthes were weak in comparison to it's specific gravity. 3. The contents of ash, holocellulose, lignin were relatively high 0.74%, 83.08%, 28.79%, but that of pentosan was low 18.53%. 4. The expected uses of sycamore wood are plywood. fancy veneer, small furniture, musical instrument, door and window frame, tool handels, boxes, etc.

• Journal of the Korea Furniture Society
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• v.24 no.3
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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.