• Title/Summary/Keyword: Wood construction

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A Study on the Trimming of Wood in the Construction of the Palace in the 2nd half of the Choseon Dynasy (조선후기(朝鮮後期) 궁궐공사(宮闕工事)의 목재치련(木材治鍊)에 관한 연구)

  • Lee, Kweon-Yeong;Kim, Soon-Il
    • Journal of architectural history
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    • v.8 no.1 s.18
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    • pp.9-28
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    • 1999
  • Broadly speaking, this paper is concentrated on the trimming of the wood demanded for the palace, constructed in the 2nd half of the Choseon Dynasty. To be concrete, this is the study on the craftman and craftmanship corncerned with the trimming of the wood, its system, and terms of payment of his wages, Construction reports, financial reports, job slips, written estimates, bills for payment, and other documents in those days are examined for the study. Following conclusions have been reached through the study. 1) The operation system of whole construction office and its suboffice was very specialized and systematized from the early 19th century. 2) The craftman engaged in trimming of the wood was subdivided by work function. 3) The craftman for its first trimming, i.e. 'keojang' or 'seonjang' had been treated as a speacial labor recruited to the mid-l8th century, after that, was enrolled into the craftman. 4) A unit cost of its first trimming was firstly appropriated into the reconstruction of the Kyongwoon Palace in the early 20th century, and it was very subdivided for a personnel management. 5) Contract works were widely applied to all workers engaged in the reconstruction for an efficiency of the accomplishments.

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Flame Retardant Performance of Functional Oil Stains According to the Mixing Ratio of Inorganic Flame Retardants and Phosphorus Flame Retardants (무기계 방염제와 인계 방염제 혼합비율에 따른 기능성 오일스테인의 방염성능)

  • Lee, Ju-Won;Lee, Sang-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.11a
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    • pp.29-30
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    • 2023
  • Wood is a construction material that has the advantages of carbon dioxide storage ability, noise reflection, and eco-friendliness. In order to use wood for a long time, you must use wood-specific paint, which is called oil stain. Oil stain improves water resistance and moisture resistance, but has the disadvantage of being weak against fire. This is because the oil contained in the oil stain causes a chemical reaction, and this chemical reaction causes the oil stain to spontaneously ignite, igniting nearby combustible materials and causing frequent fires. To improve this, in this study, different flame retardants were mixed and added to oil stain to produce functional oil stain. In addition, we would like to apply it to wood to check glow time and carbonization area. As a result of the experiment, it shows the best performance when mixed at 30(15 + 15)(%) and added to oil stain. The remaining burn time is satisfied from 10% for all samples, and the carbonized area is satisfied when it is 30%.

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Tuned vibration control in aeroelasticity of slender wood bridges

  • Tesar, Alexander
    • Coupled systems mechanics
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    • v.1 no.3
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    • pp.219-234
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    • 2012
  • Tuned vibration control in aeroelasticity of slender wood bridges is treated in present paper. The approach suggested takes into account multiple functions in aeroelastic analysis and flutter of slender wood bridges subjected to laminar and turbulent wind flow. Tuned vibration control approach is presented with application on actual bridge. Some results obtained are discussed.

Evaluation of Properties of Mortar and Concrete using Wood Chip Cogeneration Plant Flooring as Fine Aggregate (목재칩 열병합 발전소 바닥재를 잔골재로 활용한 모르타르 및 콘크리트 특성 평가)

  • Kang, Suk-Pyo;Hong, Seong-Uk
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.10 no.3
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    • pp.327-334
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    • 2022
  • In this study, in order to evaluate the characteristics of mortar and concrete using wood chip cogeneration plant flooring as fine aggregate, mortar characteristics according to wood chip aggregate replacement rate and water-cement ratio as a substitute for crushed sand, and concrete characteristics according to wood chip aggregate replacement rate were compared and evaluated. The cement mortar flow according to the wood chip aggregate replacement rate showed a tendency to increase as the wood chip aggregate replacement rate increased, and the compressive strength and flexural strength increased as the wood chip aggregate replacement rate increased. The slump and air content of concrete increased as the aggregate replacement rate increased, and the compressive strength and tensile splitting strength of concrete tended to increase as the wood chip aggregate replacement rate increased. Accordingly, the possibility of using the flooring by the cogeneration plant as a fine aggregate for concrete was confirmed.

Evaluation of Friction Properties According to Normal Force and Direction of Wood Grain in Real Contact Area

  • Park, Chun-Young;Kim, Chul-Ki;Kim, Hyung-Kun;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.39 no.5
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    • pp.437-443
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    • 2011
  • In Korea, there has been a traditional post and beam wood construction with large roof load. Because a large friction is generated in wooden joint or members, it is important to evaluate the friction between wood members according to wood direction. Because most of studies have been concerned with friction between wood and steel, excluding effect of real area of contact, there are a few studies on the friction between wood members. The object of this study was to evaluate friction or coefficient of friction according to normal force and real area of contact of wood. With Japanese larch (Larix kaempferi) test specimens, five steps of normal force and combinations of test were prepared. Results indicated that normal force had almost no affection on the friction, however there was difference about friction or coefficient of friction according to real contact conditions of wood grain and contact area.

Mass Timber: The New Sustainable Choice for Tall Buildings

  • Cover, Jennifer
    • International Journal of High-Rise Buildings
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    • v.9 no.1
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    • pp.87-93
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    • 2020
  • Professionals who work in the realm of tall building design and construction are well aware that high-rises are the best solution for accommodating growing urban populations. Until recently, few would have thought to include tall wood buildings as part of that solution, but there is growing awareness that tall mass timber structures can help satisfy the need for density while addressing the need-equally urgent-for a more sustainable built environment. This paper examines the trend toward tall wood buildings in the United States, including their history and international influences, market drivers, structural performance, and economic viability, as well as building code changes that allow wood structures up to 18 stories. It highlights examples of mass timber projects, with an emphasis on benefits that impact return on investment.

A Experimental Study on Strength Properties of Mortar using Waste Wood (폐목질을 사용한 모르터의 강도특성에 관한 실험적 연구)

  • Hwang, Byoung-Jun;Gong, Min-Ho;Jung, Keun-Ho;Kim, Sung-Sik;Lee, Young-Do;Jung, Sang-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2003.11a
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    • pp.73-76
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    • 2003
  • Recently, as the alternatives to preserve environment such as effective usage of wastes or unusable resources are drawing attentions, researches and measures for the two tasks, which are reuse of waste wood and development of eco-friendly materials, are being examined and established in various fields. However, they are still insufficient. Therefore, in this study, for the efficient application of waste woods and eco-friendly effects, mortar was produced using sawdust as the waste wood and mineral material cement for combination, in order to produce inorganic boards using waste woods, which were made when sawing. This study attempted to suggest a basic material about the physical properties of mortar, which used waste woods, after examining the features of wood mixture rate, water-cement rate, congelation according to the mixture rate of the setting accelerator, specific gravity, compression intensity, and bending intensity as experiment factors.

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Composite Wood-Concrete Structural Floor System with Horizontal Connectors

  • SaRibeiro, Ruy A.;SaRibeiro, Marilene G.
    • International Journal of Concrete Structures and Materials
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    • v.9 no.1
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    • pp.61-67
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    • 2015
  • The concept of horizontal shear connection utilization on wood-concrete beams intends to be an alternative connection detail for composite wood-concrete decks. The volume of sawn-wood is over three times more expensive than concrete, in Brazil. In order to be competitive in the Brazilian market we need a composite deck with the least amount of wood and a simple and inexpensive connection detail. This research project uses medium to high density tropical hardwoods managed from the Brazilian Amazon region and construction steel rods. The beams studied are composed of a bottom layer of staggered wood boards and a top layer of concrete. The wood members are laterally nailed together to form a wide beam, and horizontal rebar connectors are installed before the concrete layer is applied on top. Two sets of wood-concrete layered beams with horizontal rebar connectors (6 and 8) were tested in third-point loading flexural bending. The initial results reveal medium composite efficiency for the beams tested. An improvement on the previously conceived connection detail (set with six connectors) for the composite wood-concrete structural floor system was achieved by the set with eight connectors. The new layout of the horizontal rebar connectors added higher composite efficiency for the beams tested. Further analysis with advanced rigorous numerical Finite Element Modeling is suggested to optimize the connection parameters. Composite wood-concrete decks can attend a large demand for pedestrian bridges, as well as residential and commercial slabs in the Brazilian Amazon.

Flame Resistance and Durability of Compressed Structural Wood through Microwave Heat Drying Method (마이크로파 가열건조법에 의한 압축 구조용 목재의 방염 및 내구성)

  • Lim, Nam-Gi
    • Journal of the Korea Institute of Building Construction
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    • v.11 no.2
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    • pp.162-170
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    • 2011
  • As the result of implementing a treated material test and durability test after quickly drying S.P.F. species, a type of softwood structural material, within a short period time, soaking it in liquid phosphate flame proof agent for an hour, microwave heating it, and compressing it from 3.8cm to 1cm, when setting the appropriate heating time of microwave heating at 7 minutes at 5kW, it is observed that it satisfies the target water content (4~5%). It is shown that in a water content measurement of the wood that is compressed after being softened by soaking in the flame proof agent, drying and heating at 3kW for 9 minutes, all specimens satisfied 12~14%, the appropriate water content for exterior wood. Also, it is shown that in terms of the flame performance obtained through a flame resistance treatment of the compressed wood and a treated material test, the specimen soaked in flame proof agent for 30 minutes was the most excellent, and that the performance test result of the compressed wood in all areas, such as nail withdrawal resistance, compression, bending strength, and shearing strength, were all improved in their mechanical features to twice to three times better performances.

An Experimental Study on the Development of Fire-retardant Treated Wood for Construction (건축용 난연 목재 개발에 대한 실험 연구)

  • Seo, Hyun Jeong;Kim, Nam Kyun;Jo, Jeong Min;Lee, Min Chul
    • Journal of the Korean Society of Safety
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    • v.32 no.5
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    • pp.149-156
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    • 2017
  • This study investigates fire-retardant performances and combustion/thermal characteristics of fire-retardant treated wood by comparing them with those of fire-retardant untreated wood from the expreimental resutls of cone calorimeter and thermo-gravimetric(TG) analyzer. Hazardousness of combustion product gases for fire-retardant treated wood and untreasted wood were also observed from the results of internal finish material incombustibility test according to the Korea standard code of KS F 2271. In this study, we also tried to improve the fire retardant performance of wood by applying fire-retardant chemical composites, and to secure the fire safety performance in buildings. Red pine (Pinus densiflora) was selected as a test specimen because it is mostly used as a building material in Korea. Fire retardant chemical composites (FRCs) were prepared by mixing boron, phosphorous, and nitrogen species and treated by press-impregnation method. Water-based FRCs were composed of 3% boric acid($H_3BO_3$), 3% borax decahydrate($Na_2B_4O_7$), 8% ammonium carbonate($(NH_4)_2CO_3$), diammonium phosphate ($(NH_4)_2HPO_4$) varied from 10-30% and potassium carbonate($K_2CO_3$) varied from 10-30%. From the test results of cone calorimeter, TG analysis and gas hazard assessments, newly proposed were the optimal composition and production methods of FRCs which can sufficiently meet fire-retardant level 3 based on Korea law of construction. Thus, the FRCs, developed in this study, are anticipated to contribute to the improvement of fire safety and widespread of usage in wood as building materials.