• Title/Summary/Keyword: beam repair

Search Result 164, Processing Time 0.036 seconds

The Architectural Crafts as a Code of Manners and Their Historical Changes in Palatial Buildings and Royal Residences in the Late Joseon Dynasty (조선후기 궁실건축에 사용된 격식기법의 유형과 변천)

  • Ahn, So-Hyeon;Jeon, Bong-Hee
    • Journal of architectural history
    • /
    • v.28 no.6
    • /
    • pp.43-54
    • /
    • 2019
  • The grade of East Asian architecture is generally classified by the size, the shape of the roof, and the type of bracket set. The craftsmanship of columns, beam, purlin, stylobate, column base stone and paintwork is also a contributing factor for such classifications. These classifications can be found not only in historical documents such as 「Oksajo(屋舍條)」 of 『Samguksagi(三國史記)』 but also in 「house details regulations of residential architecture(家舍規制)」 of Joseon Dynasty. However, there are differences in detailed designs among the same grade of architecture regardless of the classification. In this research, the Palace, the Royal Residence(宮家), and the Jaesil(齋室) are considered as the Palatial Buildings and Royal Residences. And the advanced architectural o details which appear only in the Royal Architectures are defined as the 'The Architectural Crafts as a Code of Manners'. The Architectural Crafts as a Code of Manners is detailed design, which can be seen as fabrication of materials and supplementary factors. The Architectural Crafts as a Code of Manners used in the Palatial Buildings and Royal Residences reveal the types and their historical changes. This research will present a basis for the repair and restoration of cultural heritages to be carried out in the future, and also prevent them from further damages, thus help to preserve the cultural heritages.

Leukocyte- and platelet-rich fibrin as an adjuvant to the surgical approach for osteoradionecrosis: a case report

  • Maluf, Gustavo;Caldas, Rogerio Jardim;Fregnani, Eduardo Rodrigues;da Silva Santos, Paulo Sergio
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.46 no.2
    • /
    • pp.150-154
    • /
    • 2020
  • We present a case of osteoradionecrosis treated with leukocyte- and platelet-rich fibrin (LPRF) and surgery and followed up with clinical and tomographic investigations. A 65-year-old woman presented with pain in the posterior region of the right palate. Her medical history included cardiovascular disease and squamous cell carcinoma in the anterior region of the floor of the mouth that had been treated with intensity-modulated radiation therapy. Measurements of isodose curves showed a full dosage of 6,462.6 cGy in the anterior mandibular region, whereas that in the posterior region on the right side of the maxilla reached 5,708.1 cGy. Osteotomy was performed using rotary instruments, and debridement and placement of two LPRF membranes were also carried out. New gum tissue with no bone exposure was noted 14 days postoperatively. Tissue repair was complete, and the patient had no further complaints. During a 39-month follow-up period, the oral mucosa remained intact, and the patient was rehabilitated with a new upper denture. Since there is no consensus regarding the best protocol to treat osteoradionecrosis, LPRF might be an interesting adjuvant to a surgical approach. The use of LPRF is simple and reduces operational costs, time of handling, probability of technical failure, and associated morbidities for patients with osteoradionecrosis.

Evaluation of Physical and Mechanical Characteristics of Korean Epoxy Asphalt Mixtures (국산 에폭시 아스팔트 혼합물의 물리.역학적 특성 평가)

  • Kim, Byung-Hun;Baek, Jong-Eun;Lee, Hyun-Jong;Park, Hee-Mun
    • International Journal of Highway Engineering
    • /
    • v.14 no.1
    • /
    • pp.17-24
    • /
    • 2012
  • This study evaluated the performance of Korean epoxy asphalt mixtures using several laboratory tests. Four types of epoxy asphalt mixtures were manufactured based on 13mm dense graded asphalt mixtures: three Korean and one Japanese epoxy asphalt mixtures where 20% or 40% of asphalt binder was replaced by epoxy resins. Curing time was determined as 3 and 6 hours for the mixtures containing 40% and 20% of epoxy resins, respectively. From the laboratory tests including wheel tracking, indirect tension fatigue, bending beam, and moisture susceptibility tests, it was concluded that the epoxy asphalt mixtures had superior performance than conventional asphalt mixtures except moisture susceptibility. Also, the performance of the Korean epoxy asphalt mixtures was comparable to the Japanese mixtures. Thermal coefficient, bond strength, and indirect tension tests were conducted to examine the applicability of the Korean epoxy asphalt mixtures to concrete repair. Its adhesion was strong enough to be bonded to surrounding concrete materials and its tensile strength was comparable to the concrete, but thermal expansion coefficient was 5 times greater than the surrounding concrete.

Study on Critical Impact Point for a SB2 Class Flexible Barrier (SB2등급 연성베리어의 충돌지점(CIP)에 대한 연구)

  • Heo, Yeon Hee;Kim, Yong Guk;Ko, Man Gi;Kim, Kee Dong
    • International Journal of Highway Engineering
    • /
    • v.15 no.4
    • /
    • pp.127-133
    • /
    • 2013
  • PURPOSES : The impact performance of flexible barrier system such as structural response, vehicular motion and occupant safety vary depending on the impact point. Thus, to properly evaluate the performance of a flexible barrier system, impact should be made to a point which will lead to the worst possible results. This point is called the Critical Impact Point (CIP). This paper presents the way to determine the CIP for a SB2 class flexible barrier system which is consisted of Thrie-Beam rail and circular hollow tube post of 2m span. METHODS: Barrier VII simulations were made for impact points; Case 1 at a post, Case 2 at 1/3 span downstream from a post, Case 3 at middle of the span, Case 4 at 2/3 span downstream from a post. For the structural performance (deflections), impact simulation of 8000kg-65km/h-15degree was used, and for vehicle motion and occupant safety, simulation of 1300kg-80km/h-20degree impact was made and analysed. RESULTS: Case 1 gave the largest dynamic deflection of 75.72cm and also gave the largest snag value of 44.3cm. Occupant safety and exit angle of the vehicle after the impact were not sensitive to the impact point and were all below the allowable limit. CONCLUSIONS : For the SB2 class flexible barrier system's CIP can be regarded as a post which is sufficiently away from the end of Length of Need in order to avoid the end-effect of the barrier system. It can be more economic in the long run because the normal concrete pavement material is likely to cost more due to higher probability of maintenance and repair and higher social cost due to traffic accident, etc.

Crack Control of the Upside of Double Tee Slab and Inversed Tee Beam Joint (더블티 슬래브-역티형 보 접합부 상부의 균열억제를 위한 실험연구)

  • Nam, Sang-Uk;Song, Han-Beom;Yi, Waon-Ho;Yang, Won-Jik;Baik, Young-Soo;Tae, Kyung-Hoon
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2008.04a
    • /
    • pp.345-348
    • /
    • 2008
  • Recently, demand is caused that new building environment of value added rising demand on the lines of becoming bigger, manhattanize of structure and becoming high standard of structure in a construction site and influx of advanced foreign nation technique. To satisfy these requirements for alternative, structures applied to the PSC, PC is increasing. Double Tee Slab is possible for long length structure and applied to the method of construction. When assembling Double Tee Slab produced by the factory in the field, becamed carry-out topping concrete in upper, but occurred crack to slab line. There is no structural problem to crack occurred in upper, waterproof in maintenance and repair of structure due to a conservative cause several problems.

  • PDF

Monitoring the failure mechanisms of a reinforced concrete beam strengthened by textile reinforced cement using acoustic emission and digital image correlation

  • Aggelis, Dimitrios G.;Verbruggen, Svetlana;Tsangouri, Eleni;Tysmans, Tine;Van Hemelrijck, Danny
    • Smart Structures and Systems
    • /
    • v.17 no.1
    • /
    • pp.91-105
    • /
    • 2016
  • One of the most commonly used techniques to strengthen steel reinforced concrete structures is the application of externally bonded patches in the form of carbon fiber reinforced polymers (CFRP) or recently, textile reinforced cements (TRC). These external patches undertake the tensile stress of bending constraining concrete cracking. Development of full-field inspection methodologies for fracture monitoring are important since the reinforcing layers are not transparent, hindering visual observation of the material condition underneath. In the present study acoustic emission (AE) and digital image correlation (DIC) are applied during four-point bending tests of large beams to follow the damage accumulation. AE helps to determine the onset of fracture as well as the different damage mechanisms through the registered shifts in AE rate, location of active sources and change in waveform parameters. The effect of wave propagation distance, which in large components and in-situ can well mask the original information as emitted by the fracture incidents is also discussed. Simultaneously, crucial information is supplied by DIC concerning the moments of stress release of the patches due to debonding, benchmarking the trends monitored by AE. From the point of view of mechanics, conclusions on the reinforcing contribution of the different repair methodologies are also drawn.

In-situ Production Analysis of Composite Precast Concrete Members of Green Frame

  • Lim, Chae-Yeon;Joo, Jin-Kyu;Lee, Goon-Jae;Kim, Sun-Kuk
    • Journal of the Korea Institute of Building Construction
    • /
    • v.11 no.5
    • /
    • pp.501-514
    • /
    • 2011
  • Recently, there have been many cases in which the difficulty of repair and replacement of principal elements in the bearing wall structure for apartment buildings, which is a major part of apartment buildings in Korea, has led to the reconstruction of buildings rather than their remodeling. To address this problem, the Korea government now allows a floor area ratio of up to 20 %, and has relaxed the building height limits to encourage the use of a rahmen structure instead of a bearing wall structure. However, since reinforced concrete rahmen structures have many problems, including higher floor height and greater construction cost, a great deal of research into rahmen composite precast concrete structures have been conducted. Green Frame, one of the developed prototypes, is expected to provide economic benefits through in-situ production for precast concrete column and beam. For in-situ production of composite precast concrete members, a detailed plan for production, curing, and installation is needed. However, it needs to be confirmed that the space is sufficient to produce the precast concrete members on-site before planning those activities. Therefore, this study proposes in-situ production analysis of composite precast concrete members of Green Frame with the evaluation of structural safety and available area on the parking structure. The result of this study shows that the in-situ production of precast concrete members is possible through a case study.

Residual foreign body inflammation caused by a lumber beam penetrating the facial region: a case report

  • Jun Ho Choi;Sang Seong Oh;Jae Ha Hwang;Kwang Seog Kim;Sam Yong Lee
    • Archives of Craniofacial Surgery
    • /
    • v.24 no.1
    • /
    • pp.37-40
    • /
    • 2023
  • Penetrating wounds to the face are cosmetically devastating and can be life-threatening. If the foreign body causing the penetrating wound is a piece of wood, small remnants might be left behind after the initial treatment. A 33-year-old male patient presented to the emergency center after a piece of lumber pierced his face as a passenger in a traffic accident. The patient's vital signs were stable, and emergency surgery was performed to remove the foreign body and repair the soft tissue. No noteworthy complications were seen after open reduction and internal fixation of the facial bone fractures. Seven months after the accident, the patient underwent scar revision along with full-thickness skin grafting for post-traumatic scars. After the surgery, pus-like discharge which was not previously present was observed, and the graft did not take well. A residual foreign body, which was the cause of graft failure, was found on computed tomography and the remaining foreign body was removed through revision surgery. The patient is receiving outpatient follow-up without any complications 6 months after surgery. This case demonstrates the importance of performing a careful evaluation to avoid missing a residual foreign body, especially if it is of wooden nature.

Analysis of Laterally Loaded Pile-Bent Structure with Varying Cross-sectional Area (변단면 파일벤트 구조의 수평거동 분석)

  • Jeong, Sang-Seom;Sung, Chul-Gyu;Ko, Jun-Young;Kim, Soo-Il
    • Journal of the Korean Geotechnical Society
    • /
    • v.25 no.4
    • /
    • pp.69-75
    • /
    • 2009
  • The load distribution and deformation of pile-bent structures are investigated using a numerical study. A numerical analysis that takes into account the effects of varying cross-sectional area was performed for different pier diameters, loading steps, and soil conditions. Through the comparison study, it is shown that the location of maximum bending moment is almost the same per each loading step, regardless of varying cross-sections. However, the member force (i.e., stress of pile material) has the largest value at the ground surface when the cross-section is changed. Based on the results obtained, it is found that the location of maximum member force influences highly the behavior of pile-bent structure with varying cross-sections for repair works.

Experimental Study on the Flexural Behavior Effect of RC Beam Repaired and Strengthened by Latex Modified Concrete (라텍스개질콘크리트로 보수·보강된 RC 보의 휨 거동에 관한 실험적 연구)

  • Kim, Seong-Hwan;Yun, Kyong-Ku;Kim, Yong-Gon
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.29 no.5A
    • /
    • pp.503-510
    • /
    • 2009
  • Latex modified concrete (LMC) is a successful polymer-portland cement concretes, which have been developed and used for many years, in overlaying bridge decks and resurfacing industrial floors. The excellent bond strength to substrate, easy application and high resistance to impact, abrasion, wear, aggressive chemicals and freeze-thaw deterioration have made this material used widely. The objective of this study was to determine experimentally the load-deflection response and ultimate strength of reinforced RC beams. The cracking patterns and the mode of failure were observed. Because of excellent bond strength and repairing effects, the RC beams repaired by LMC at compression or tension zone showed over 100% recovery from damaged structures. The RC beams overlaid by LMC showed significant improvement at load carrying capacity as overlay thickness increases. However, the beams repaired of tension zone without shear stirrups almost showed no strengthen effect, and indicated an interfacial failures. The interfacial behavior was estimated by numerical method adopting the concept of shear flow.