• Title/Summary/Keyword: transverse joint

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A Study on the Evaluation System of Jointed Concrete Pavement (콘크리트포장 줄눈부의 평가에 관한 기법연구)

  • Park, Je-Seon;Lee, Joo-Hyung;Hong, Chang-Woo;Lee, Jung-Ho
    • Journal of Industrial Technology
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    • v.19
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    • pp.245-251
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    • 1999
  • The joint in the concrete pavement provides a control against transverse or longitudinal cracking at slab, which may be caused by temperature or moisture variation during or after hydration. Without control of cracking, random crack may cause more serious distresses and result in structural or functional failure of pavement system. Sometimes, joint itself, purposed to control crack, may cause a distresses in joint due to its inherent weakness in structural integrity. Thus, the load transfer capacity in joint is very important for serviceability and durability. The purpose of this dissertation was to develop an evaluation system at joints of jointed concrete pavement using finite element analysis was performed using ILLI-SLAB program with a selected variables which might affect fairly to on the performance of transverse joints. The most significant variables were selected from precise analysis. It was concluded that the variables which most significantly affect to pavement deflections are the modulus of subgrade reaction(K) and the modulus of dowel/concrete interaction(G), and limiting criteria on the performance of joints at JCP at 300pci, 500,000 lb/in. respectively.

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Experimental Study on the Behavior of Hybrid Beam-Column Joints Consisted of Reinforced Concrete Column and Steel Beam (철근콘크리트 기둥 및 철골보로 구성된 복합구조의 접합분 거동에 관한 실험적 연구)

  • Choi, Keun-Do;You, Young-Chan;Lee, Li-Hyung
    • Journal of the Korea Concrete Institute
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    • v.15 no.2
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    • pp.297-304
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    • 2003
  • This paper presents the test results of RCS(Reinforced Concrete Steel) beam-column joint with various types of transverse reinforcements such as small-column-type transverse reinforcements, four-piece ㄱ-shape assembled hoops and four-piece ㄱ-shape welded hoops. Five interior beam-column joint specimens were tested to examine the seismic performance and the shear strengths. From the test results, it was found that all the specimens sustained their strength at large levels of story drift(${\theta}$=0.035) without significant loss of strength and stiffness. Therefore it was concluded that the seismic performance and shear strength of the proposed RCS joint are at least the same as those of the specimen with conventional reinforcing details. Also, the contribution of the outer panel to the shear strength of the joint should be evaluated by the compression strut mechanism rather than compression field mechanism.

Effect of Transverse Reinforcement on the Shear Friction Capacity of Concrete Interfaces with Construction Joint (시공줄눈이 있는 콘크리트 경계면의 전단마찰 내력에 대한 보강철근의 영향)

  • Hwnag, Yong-Ha;Yang, Keun-Hyeok
    • Journal of the Korea Concrete Institute
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    • v.28 no.5
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    • pp.555-562
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    • 2016
  • The objective of the present study is to evaluate the shear transfer capacity of transverse reinforcement at the concrete interfaces with smooth construction joint. The transverse reinforcing bars were classified into two groups: V-type for the arrangement perpendicular to the interface and X-type for inclined-crossing arrangement. The transverse reinforcement ratio at the interface varied from 0.0045 to 0.0135 for V-type and 0.0064 to 0.0045 for X-type. The mechanism analysis proposed for monolithic concrete interface, derived based on the upper-bound theorem of concrete plasticity, was modified to evaluate the shear friction capacity of concrete interfaces with smooth construction joint. Test results showed that the specimens with X-type reinforcement had lower amount of relative slippage at the interface and higher shear friction capacity than the companion specimens with V-type reinforcement. This observation was independent of the unit weight of concrete. The mean and standard deviation of the ratios between the experimental shear friction strength of smooth construction joints and predictions obtained from the proposed model are 1.07 and 0.14, respectively.

Effects of Alignment of the Thoracic Spine and Ankle Joint on Muscle Activation During Sling Exercise

  • Hojin Shin;Gyeongseop Sim
    • Physical Therapy Rehabilitation Science
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    • v.12 no.3
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    • pp.340-345
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    • 2023
  • Objective: The purpose of this study was to investigate the effect of thoracic spine and ankle joint alignment on trunk and upper limb muscle activity during trunk forward lean exercise using a sling. Methods: 25 subjects participated in this study. All subjects performed trunk forward lean exercise using a sling under four conditions according to the alignment of the thoracic spine and ankle joints. Trials were performed 3 times in each condition. Muscle activity of the trunk and upper extremity was measured using electromyography. Results: In the dorsiflexion, the thoracic kyphosis condition showed significantly higher muscle activity in the pectoralis major, rectus abdominis, latissimus dorsi, transverse abdominis than dorsiflexion(p<0.05). In the plantar flexion, thoracic kyphosis condition showed significantly higher muscle activity in pectoralis major, transverse abdominis, latissimus dorsi muscle activity than dorsiflexion(p<0.05). Conclusions: Regardless of ankle alignment, thoracic kyphosis condition increased the activity of the pectoralis major, transverse abdominis, latissimus dorsi. Therefore, regardless of the alignment of the ankle, it is recommended to perform the trunk forward lean exercise using a sling in thoracic kyphosis.

Experimental Study on Strengthening Transverse Joints between Precast Concrete Slabs

  • Park, Jong-Jin;Cheung, Jin-Hwan;Shin, Su-Bong
    • KCI Concrete Journal
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    • v.12 no.2
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    • pp.45-54
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    • 2000
  • Precast R.C. slabs are being used widely for the construction of bridge structures due to their simplicity in construction processes. However, one of the disadvantages in precast R.C. slabs is the existence of transverse joints between two precast slabs. The transverse joints are structurally fragile and the task of strengthening the joints is difficult one due to their structural discontinuity. The aim of this study was to improve the behavior of transverse joints between precast R.C. slabs by introducing prestress with external cables. Three steel-concrete composite bridge specimens, which were prestressed with the external cables anchored on steel girders, were fabricated in the laboratory. Both pretension and post-tension methods were applied to introduce prestressing on the concrete slab with a straight tendon arrangement. Static tests were conducted at service load and ultimate load test was performed to evaluate punching shear capacity of the transverse joint. In this paper, two prestressing methods were tested and their effects were evaluated with respect to the elastic behavior and ultimate loading capacity of the transverse joints.

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Kinematic Characteristics during of Gait in Parkinson's Disease Patients (파킨슨 질환 환자의 보행시 운동형상학 특성)

  • You, Jae-Eung;An, Chang-Sik
    • The Journal of Korean Physical Therapy
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    • v.13 no.2
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    • pp.453-458
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    • 2001
  • The aim of this study is to present the basic reference data of age and specific gait parameters for Parkinson's Disease Patients. The basic gait parameters were extracted from 5 patients, 5 men and 65 years of age using VICON 512 Motion Analyzer. The temporal gait parameters and kinematic parameters is data of Parkinson's Disease Patients. The results were as follows; 1. The cadence, velocity, stride length decreased and single limb support period, double limb support period increased than normal adult in the temporal parameters. 2. The mean angles of joint pelvic tilt and hip, knee, ankle joint decreased than normal adult at kinematic characteristics on sagittal plane. 3. The mean angles of joint pelvic tilt and hip, knee joint has no difference than normal adult at kinematic characteristics on coronal plane. 4. The mean angles of joint pelvic tilt, hip joint no difference and internal, external rotation in ankle joint significantly decreased than normal adult at kinematic characteristics on transverse plane.

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Repair of Closed Bilateral Mandibular Fractures Using Bone Plate and Screw in Dogs (개에서 골판을 이용한 비개방성 양측성 하악골절의 수복)

  • 정순욱;한현정;김지선;김준영;정만복
    • Journal of Veterinary Clinics
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    • v.20 no.1
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    • pp.138-141
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    • 2003
  • First case, a one-year-old female Shih Tzu weighing 3 kg with closed transverse fractures of bilateral mandibular body between 2nd and 3rd premolar teeth were treated surgically with bone plates and screws, and cranial luxation of temporomandibular joints were reduced to closed method. Second case, a 8.4 years old male Yorkshire terrier weighing 2.6 kg with closed transverse/oblique fractures of bilateral mandibular body between premolar and molar teeth were treated surgically with bone plates and screws. Radiographic examination revealed that the fractures in two cases fixed well and temporomandibular joint was stabilized. One month after operation, jaw activity was excellent and malocclusion wasn't observed.

Welding Distortions on Rectangular Butt Welded Plate by Shielded Metal Arc Welding Process (피복(被覆) Arc용접(熔接)으로 Butt이음된 사각평판(四角平板)의 용접변형(熔接變形))

  • J.E.,Park;S.J.,Yim;B.S.,Yoon
    • Bulletin of the Society of Naval Architects of Korea
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    • v.17 no.2
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    • pp.21-32
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    • 1980
  • The welding distortions, transverse shrinkage and angular change, on the butt welded joint made by the process of shielded metal arc welding, were studied on the basic study of bead on plate weld. On the study of bead on plate weld, the temperature distribution on the plane normal to the direction of the weld line was assumed to be parabolic. The form of the distortion formulas of welded joint for transverse shrinkage and angular change were derived theoretically. Also, the experiments were performed about three cases, for changing type, sizes of welding electrodes and types of grooves, welding on mild steel plate, to compare theoretical study and experiments. It was found that the theoretical study was in good agreement with the result of experiment. Also, the optimal welding conditions for reducing weld distortions were suggested.

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An Experimental Study on Shear Behaviorof Reinforced Concrete Beam-Column Joints (철근콘크리트 보-기둥 접합부의전단거동에 관한 실험적 연구)

  • Kim, Jin-Young;Oh, Ki-Jong;Lee, Jung-Yoon
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.105-108
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    • 2006
  • Current ACI and AIJ guidelines only address the importance of the concrete strength and geometry of the joint. There are no significant attention paid to other variables. In addition, the current design code doesn't predict the ductility of the beam-column assemblies. The former researcher proposed the analytical model to predict the shear strength of the joint panel as well as the ductility of the beam-column assemblies in year 2004. In this study, the experiments to investigate shear behavior of reinforced concrete beam-column joints and to verify proposed model were carried out, based on the experimental results. As the formal researcher proposed, the factor K (K=0.5), the ductility of BJ-failure was predicted reasonably when the transverse reinforcement ratio exceeded 0.0186. However, the proposed equation showed a large discrepancies in the ductility estimating when transverse reinforcement ratio was below 0.0186.

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A study on weld distortion in butt and fillet welds of a steel plate by flux cored arc welding (플럭스코어드 용접으로 맞대기 및 필렛 용접된 판의 용접변형)

  • 안성철;유순영;조성택
    • Journal of Welding and Joining
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    • v.7 no.4
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    • pp.22-29
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    • 1989
  • In this paper weld distortion both in butt and fillet welds by flux cored arc welding has been investigated by changing welding parameters such as heat input and plate thickness, and the weld distortion was expressed as a function of welding parameters adopting the inherent strain theory as proposed by Watanabe and Satoh in 1961. As results of the research it is proposed that transverse shrinkage in root pass butt welds in proportional to ln[(Q/t_-tan.theta.] where Q is heat input(cal/mm), t is plate thickness(mm), and 2.theta. is groove angle(degree), and angular distortion .phi.(radian) in one pass of fillet welds has the following relationship: .phi..var.(Q/ $t^{1.5}$)$^{3}$exp[-(Q/ $t^{1.5}$ )$^{2}$3/] These equations provide us with basic tools to predict the amount of weld distortion in welded structures.

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