• Title/Summary/Keyword: light frame construction

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Construction quality issues in performance-based wind engineering: effect of missing fasteners

  • van de Lindt, John W.;Dao, Thang Nguyen
    • Wind and Structures
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    • v.13 no.3
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    • pp.221-234
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    • 2010
  • In light-frame wood construction, missing roof-sheathing fasteners can be a relatively common occurrence. This type of construction makes up the vast majority of the residential building stock in North America and thus their performance in high winds, including hurricanes, is of concern due to their sheer number. Construction quality issues are common in these types of structures primarily because the majority are conventionally constructed and unlike steel and reinforced concrete structures, inspection is minimal except in certain areas of the country. The concept of performance-based wind engineering (PBWE), a relatively new paradigm, relies on the assumption that building performance under wind loads can be accurately modeled. However, the discrepancy between what is designed (and modeled) and what is built (the as-built) may make application of PBWE to light-frame wood buildings quite difficult. It can be concluded from this study that construction quality must be controlled for realistic application of PBWE to light-frame wood buildings.

Density and Water Absorption Ratio Property of the Magnesium Oxide Matrix According to Wood flour Addition Ratio (목분의 첨가량에 따른 산화마그네슘 경화체의 밀도 및 흡수율 특성)

  • Jung, Byeong-Yeol;Kim, Heon-Tae;Lee, Sang-Soo;Song, Ha-Young
    • 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.

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Thermal Resistance and Condensation in the Light-frame Timber Wall Structures with Various Composition of Insulation Layers

  • Jang, Sang Sik;Lee, Hyoung Woo
    • 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.

The study on the system reliability and code conversion for the probability based design (확률 기반 설계법을 위한 코드 변환과 시스템 신뢰도에 대한 고찰)

  • Kim, Gwang-Chul
    • Journal of the Korea Furniture Society
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    • v.20 no.5
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    • pp.440-456
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    • 2009
  • Because PBD was started as a design tool for steel construction and concrete construction, it was able to applied to the post and beam method of wooden building constructions. But, it may not suitable to light frame wooden construction that is becoming popular in domestic construction market due to the economical efficiency and the constructive simplification. Owing to the share effects between member and sheathing material or among structural members, light frame wooden construction is different from post and beam construction that use a single structural member. Therefore, consideration on the system analysis and system design are urgently needed to use in actual life and inspect the reliability of structures from the system view. With this in mind, code conversion from ASD to PBD that is pressing issue in domestic wooden building construction was studied, also various countries status about PBD were considered and then approaching methods on the system reliability were referred. Finally, several considerations for the development of PBD were explored. PBD should be considered as, not only a new structural design process that select sizes of structural member, but a industrial tool that can lead a development of more reliable wood products. A strongest point of PBD is independent of various construction materials and construction types.

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Water Absorption Ratio and Flexural Strenght of the Magnesium Oxide Light Weight Matrix According to the Powdery Modified Sulfur Addition Ratio (분말형 개질유황 첨가율에 따른 산화마그네슘 경량 경화체의 흡수율 및 휨강도 특성)

  • Yoo, Yong-Jin;Jeong, Byeong-Yeol;Lee, Sang-Soo;Song, Ha-Young
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.114-115
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    • 2014
  • Recently, the construction structure repeats the brilliant development including the shper high rising, high functionalization, environmental friendliness, conversion to ubiquitous, and etc. upon with the construction industry development and it is continually soothed. Meanwhile, as to the construction structure of the modern society, the research for corresponding to the box-frame construction way where the response to the diversity of the life of the occupant is difficult is needed. Thus, the lightweight of the structure is the important factor in order to secure the functionality. Therefore, this research tries to study the water absorption ratio and flexural strenght of the magnesium oxide light weight matrix according to the powdery modified sulfur addition ratio.

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A Study on the Performance Experiments of Lightweight Wall of Long-life Housing by Ceiling Infill System (천장 인필시스템에 따른 장수명주택 경량벽체의 성능실험에 관한 연구)

  • Seo, Dong-Goo;Lee, Jong-Ho;Kim, Eun-Young;Hwang, Eun-Kyoung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.247-248
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    • 2018
  • In order to secure the variability of long-life housing, dry walls are used. The composite gypsum board panel is the most frequently used infill system for the wall, and it is an excellent construction method in terms of constructability and economic feasibility. However, there are also problems such as the destruction of Ondol pipes at the bottom floor and being unable to fix the light weight steel frame (M-bar) when a variable composite gypsum board panel is used. To solve such problems, a wall with a method of fixing only the top part without fixing the bottom floor is developed, but it is difficult to identify the durability of ceiling frame according to the tensile force of stud and the safety according to the Stiffness and impact resistance (soft body) of ceiling frame. Therefore, this study verified the effectiveness of infill system for the wall by conducting experiment on the stiffness and impact resistance of composite gypsum board panel according to the reinforcement of ceiling frame (wooden frame, double saw-toothed bracket, Cross M-bar). As a result, it was possible to secure the safety of wooden frame while the impact resistance and the Stiffness of double saw-toothed bracket and cross M-bar were not secured.

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Lateral Resistance of Reinforced Light-Frame Wood Shear Walls

  • Hyung Woo LEE;Sang Sik JANG
    • Journal of the Korean Wood Science and Technology
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    • v.51 no.1
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    • pp.58-66
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    • 2023
  • In light-frame timber construction, the shear wall is one of the most important components that provide resistance to lateral loads such as earthquakes or winds. According to KDS (Korea Design Standard) 42 50 10, shear walls are to be constructed using wood-based structural sheathing, with studs connected by 8d nails spaced 150 mm along the edge and 300 mm in the field. Even though small-scale residential timber building can be designed to exhibit seismic resistance using light-frame timber shear walls in accordance with KDS 42 50 10, only the abovementioned standard type of timber shear wall is available. Therefore, more types of timber shear walls composed of various materials should be tested to measure their seismic resistance, and the results should be incorporated into the future revision of KDS 42 50 10. In this study, the seismic resistance of shear walls composed of structural timber studs and wood-based structural sheathing with reinforced nailing is tested to evaluate the effects of the reinforcement. For the nailing reinforcement, shear wall specimens are constructed by applying nail spacings of 75-150 mm and 50-100 mm. For the shear wall specimens with one sheathing and reinforced nailing, the shear strengths are 1.7-2.0 times higher than that of the standard shear wall (nail spacing of 150-300 mm). The shear strength of the shear walls with sheathing on both sides is 2.0-2.7 times higher than that of the standard shear wall.

Nail Shear Performance of Structural Members with OSB (오에스비에 대한 각종 부재의 못전단성능)

  • Hwang, Kweonhwan;Park, Moon-Jae
    • 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.

Airtightness of Light-Frame Wood Houses built in Daejeon and Chungnam Area

  • Jang, Sang-sik;Ha, Been
    • Journal of the Korean Wood Science and Technology
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    • v.45 no.2
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    • pp.147-158
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    • 2017
  • Among the energy consumption in building, the heating energy takes the largest part. Therefore, it is important to minimize the heat energy loss in building for the reduction of overall energy use in construction. The most important points for the minimization of energy loss in building are insulation and airtightness. Especially, in wood houses, airtightness is very important for energy saving as well as increase of durability. However, the researches on airtightness of wood buildings have been started recently and are very deficient especially in Korea. In this study, air leakage properties and airtightness performance were evaluated for light-frame wood houses built in Daejeon and Chungnam area. Total 7 houses were evaluated, among which four houses (Case 1 to Case 4) were in the construction stage before interior finish and the other three houses (Case 5 to Case 7) were after completion of construction work. The tests for airtightness were conducted by pressurization-depressurization method, and the factors included in the measurements includes air leakage rate at 50 Pa (CMH50), air change rate at 50 Pa (ACH50), equivalent leakage area (EqLA) and EqLA per floor area. As a result of this study, key air leakage points in wood houses were found to be the gaps between floor and wall, the holes for wiring and plumbing, the double glasses windows and the entrance doors. The average value of ACH50 for the houses after completion of construction work was $3.5h^{-1}$ that was similar to Europe standard ($3.0h^{-1}$). ACH50 was proportional to EqLA per floor area but inversely proportional to the internal volume, the net floor area and the area of window.

Exploring the Combined Use of LiDAR and Augmented Reality for Enhanced Vertical and Horizontal Measurements of Structural Frames (골조 수직, 수평 측정작업 시 LiDAR 및 AR 기술 적용방안 제시)

  • Park, Inae;Kim, Sangyong
    • Journal of the Korea Institute of Building Construction
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    • v.23 no.3
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    • pp.273-284
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    • 2023
  • This study is centered on the combined use of LiDAR(Light Detection and Ranging) and AR(Augmented Reality) technologies during vertical and horizontal frame measurements in construction projects. The intention is to enhance the quality control procedure, elevate accuracy, and curtail manual labor along with time expenditure. Present methods for accuracy inspection in frame construction often grapple with reliability concerns due to subjective interpretation and the scope for human error. This research recommends the application of LiDAR and AR technologies to counter these issues and augment the efficiency of the inspection process, along with facilitating the dissemination of results. The suggested technique involves the collection of 3D point cloud data of the frame utilizing LiDAR and leveraging this data for checks on construction accuracy. Furthermore, the inspection outcomes are fed into a BIM (Building Information Modeling) model, and the results are visualized via AR. Upon juxtaposing this methodology with the current approach, it is evident that it offers benefits in terms of objective inspection, speed, precise result sharing, and potential enhancements to the overall quality and productivity of construction projects.