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Airtightness and Air Leakage Causes of Wooden Houses in Korea

https://research.thinkwood.com/en/permalink/catalogue1643
Year of Publication
2016
Topic
Energy Performance
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Wood Building Systems
Author
Kim, Se-Jong
Chang, Yoon-Seong
Park, Joo-Saeng
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Wood Building Systems
Topic
Energy Performance
Keywords
Korea
Airtightness
Air Leakage
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 3367-3372
Summary
The airtightness of building must be measured for the evaluation of building energy performance. To make up the reference airtightness value of wooden houses built in Korea, blower door test was carried out in the 36 houses. And, during the test, the causes of air leakage were inspected simultaneously. The result showed that the average of ACH50((air change per hour at air pressure difference 50Pa) measured from light timber frame houses was 3.5 h-1 and the post-beam construction was 5.1h-1. And, insulation with form of foams was advantageous in ensuring building airtightness than glass fiber batt. And, values below 1.5 h-1 of ACH50, threshold for application of artificial air change equipment, had appeared after 2010s. Also, the values varied according to who managed the building construction field. Although only one measurement of CLT(cross laminated timber) residential building could be obtained in 2016, the result showed good airtightness of building with 0.7 h-1.
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Characteristics of the Radio-Frequency/Vacuum Drying of Heavy Timbers for Post and Beam of Korean Style Housings Part II: For Korean Red Pine Heavy Timbers with 250 × 250 mm, 300 × 300 mm in Cross Section and 300 mm in Diameter, and 3,600 mm in Length

https://research.thinkwood.com/en/permalink/catalogue1508
Year of Publication
2011
Topic
Moisture
Material
Solid-sawn Heavy Timber
Application
Wood Building Systems
Author
Lee, Nam-Ho
Zhao, Xue-Feng
Shin, Ik-Hyun
Park, Moon-Jae
Park, Jung-Hwan
Park, Joo-Saeng
Publisher
The Korean Society of Wood Science Technology
Year of Publication
2011
Format
Journal Article
Material
Solid-sawn Heavy Timber
Application
Wood Building Systems
Topic
Moisture
Keywords
Radio-Frequency/Vacuum Drying
Moisture Gradient
Shrinkage
Case Hardening
Surface Checks
Compressive Load
Research Status
Complete
Series
Journal of the Korean Wood Science and Technology
Summary
This study examined the characteristics of radio-frequency/vacuum dried Korean red pine (Pinus densoflora heavy timbers with 250 × 250 mm (S), 300 × 300 mm (L) in cross section and 300 mm in diameter, and 3,600 mm in length, which were subjected to compressive loading after a kerf pretreatment. The following results were obtained : The drying time was short and the drying rate was high in spite of the large cross section of specimens. The moisture gradient inall specimens was gentle in both longitudinal and transverse directions owing to dielectric heating. The shrinkage of the width in the direction perpendicular to was 21 percent ~ 76 percent of that of the thickness of square timbers in the direction parallel to the mechanical pressure. The casehardening for all specimens was very slight because of significantly reduced ratio of the tangential to radial shrinkage of specimens and kerfing. The surface checks somewhat severely occurred although the occurrence extent of the surface checks on the kerfed specimens was slight compared withthat on the control specimen.
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Effect of Reserve Air-Drying of Korean Pine Heavy Timbers on High-Temperature and Low-Humidity Drying Characteristics

https://research.thinkwood.com/en/permalink/catalogue1506
Year of Publication
2014
Topic
Moisture
Material
Solid-sawn Heavy Timber
Author
Lee, Chang-Jin
Lee, Nam-Ho
Park, Moon-Jae
Park, Joo-Saeng
Eom, Chang-Deuk
Publisher
The Korean Society of Wood Science Technology
Year of Publication
2014
Format
Journal Article
Material
Solid-sawn Heavy Timber
Topic
Moisture
Keywords
Moisture Content
Temperature
Humidity
Pine
Air Drying
Shrinkage
Internal Checks
Twist
Case Hardening
Research Status
Complete
Series
Journal of the Korean Wood Science and Technology
Summary
The pre-air-drying of Korean pine before the high-temperature and low-humidity drying was shown to be effective in uniform moisture content distribution and prevention of surface check. Our results suggest that initial moisture content of the timber also plays important role in high-temperature and low-humidity drying method. The pre-air-drying also helps in the reduction of surface checks in Korean pine when compared to the Korean pine dried by only high-temperature and low-humidity. End-coating was not effective in the prevention of twist, shrinkage, case hardening and internal checks. The pre-air-drying reduces the internal tension stresses which occur during high-temperature and low-humidity drying thus decreasing case hardening and also preventing internal checks. The pre-air-drying decreases the moisture content and causes shrinkage which leads to increased twist in the Korean pine.
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Fire Resistance of Timber Framed Floor with Isolated Ceiling Assembly

https://research.thinkwood.com/en/permalink/catalogue685
Year of Publication
2014
Topic
Acoustics and Vibration
Fire
Material
Glulam (Glue-Laminated Timber)
Application
Floors
Ceilings
Author
Park, Joo-Saeng
Lee, Sang-Joon
Yeo, In-Hwan
Year of Publication
2014
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Floors
Ceilings
Topic
Acoustics and Vibration
Fire
Keywords
Heavy Impact Sound
Fire Resistance
Sound Insulation
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
Fire resistance test was performed for a floor assembly, of which stiffness was reinforced by shortening the span of floor joists by adding glulam beam in the middle of the original span, and which an additional ceiling component was installed apart from floor part. These factors are expected to show good insulation performance of timber framed floor against heavy impact sound. From full scale fire test, it is conclude that the designed and manufactured floor achieved 1 hour of fire resistance rating.
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Improvement of Prediction Accuracy of Glulam Modulus of Elasticity by Considering Neutral Axis Shift in Bending

https://research.thinkwood.com/en/permalink/catalogue1467
Year of Publication
2009
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Shim, Kug-Bo
Kim, Kwang-Mo
Park, Joo-Saeng
Publisher
Society of Wood Science and Technology
Year of Publication
2009
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Topic
Mechanical Properties
Keywords
Modulus of Elasticity
Transformed Section Method
Research Status
Complete
Series
Wood and Fiber Science
Summary
There is a discrepancy between the estimated modulus of elasticity (MOE) of glulam based on the dynamic MOE of laminates and measured MOE. The discrepancy is greater for glulam manufactured with mixed species. This study was undertaken to reduce the discrepancy between those MOE values. The error rate of predicting MOE of glulam by the transformed section method, without considering tension and compression modulus differences, was about 30%. To estimate the MOE of glulam more accurately, the differences between compression and tension modulus should be taken into account in the transformed section method. The measured tensile and compressive strain at the center of glulam under a bending load showed the movement of neutral axis toward the tension side of glulam. Therefore, the compression and tension modulus differences for each species should be identified before estimating the MOE of glulam. The prediction of glulam MOE was improved significantly by reflecting the ratio of compression and tension modulus vs dynamic MOE of laminates. The outermost of laminates in the compression side under bending load experienced plastic behavior and failure. This caused the neutral axis to move to the tension side and increased tension stress to cause the glulam to fail abruptly in tension. To improve the bending performance of glulam, reinforcing compression laminates need to be considered.
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Moment Resistance of Post-And-Beam Joints with Concealed Metallic Connectors

https://research.thinkwood.com/en/permalink/catalogue621
Year of Publication
2014
Topic
Connections
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Humbert, Jérôme
Lee, Sang-Joon
Park, Joo-Saeng
Park, Moon-Jae
Year of Publication
2014
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Connections
Mechanical Properties
Keywords
Moment Resistance
Post and Beam
Joints
Metallic Connectors
Monotonic
Reverse Cyclic Loading
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
This paper presents a study on the moment resistance of post-and-beam joints with concealed metallic connectors aimed at replacing in a more modern design the wood-wood joints of traditional Korean Hanok timber houses. Several variations of the design of the connectors are investigated to optimize the moment resistance of the joints. Experimental tests are conducted under monotonic and reversed cyclic loading. The performance of the joint is evaluated in terms of peak moment resistance, as well as ductility and energy dissipation. Results show that optimization in the design can improve the moment resistance of the joint while preventing the brittle wood fracture and favoring a more ductile plasticizing of the connector, for the benefit of safety.
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Tensile Performance of Machine-Cut Dovetail Joint with Larch Glulam

https://research.thinkwood.com/en/permalink/catalogue1509
Year of Publication
2010
Topic
Connections
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Park, Joo-Saeng
Hwang, Kweon-Hwan
Park, Moon-Jae
Shim, Kug-Bo
Publisher
The Korean Society of Wood Science Technology
Year of Publication
2010
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Topic
Connections
Mechanical Properties
Keywords
Larch
Dovetail Joints
Tensile Strength
Research Status
Complete
Series
Journal of the Korean Wood Science and Technology
Summary
Members used for the Korean traditional joints have been processed by handicraft, especially with domestic red pine species. Dovetail joint is most commonly used in woodworking joinery and traditional horizontal and vertical connections. It is able to be processed much easier to cut by handicraft and machines. However, although it is processed straight forwards, it requires a high degree of accuracy to ensure a snug fit. Also, tenons and mortises must fit together with no gap between them so that the joint interlocks tightly. A few scientific studies on the dovetail joints have been conducted so far. For the effective applications of traditional joints and domestic plantation wood species, dovetail joints were assembled by larch glulam members processed by machine pre-cut. To identify the tensile properties of through dovetail joints, larch glulam with 150 150mm in cross section were prepared. Furthermore, various geometric parameters of dovetai joints such as width, length, and tenon angle, were surveyed. The ends in the mortise was cracked mainly at a low strength level in the control specimens without reinforcements. The maximum tensile strengths of reinforced specimens considering real connections such as capital joint and headpiece on a column, increasedby handicraft, especially with domestic red pine species. Dovetail joint is most commonly used in woodworking joinery and traditional horizontal and vertical connections. It is able to be processed much easier to cut by handicraft and machines. However, although it is processed straight forwards, it requires a high degree of accuracy to ensure a snug fit. Also, tenons and mortises must fit together with no gap between them so that the joint interlocks tightly. A few scientific studies on the dovetail joints have been conducted so far. For the effective applications of traditional joints and domestic plantation wood species, dovetail joints were assembled by larch glulam members processed by machine pre-cut. To identify the tensile properties of through dovetail joints, larch glulam with 150 150mm in cross section were prepared. Furthermore, various geometric parameters of dovetai joints such as width, length, and tenon angle, were surveyed. The ends in the mortise was cracked mainly at a low strength level in the control specimens without reinforcements. The maximum tensile strengths of reinforced specimens considering real connections such as capital joint and headpiece on a column, increased by two times with shear failures on the tenon than the control specimens. The maximum tensile strength was obtained in the specimen of 25 degrees, and no difference was observed in the changes of neck widths.
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7 records – page 1 of 1.