• KCI Concrete Journal
• /
• v.12 no.1
• /
• pp.113-120
• /
• 2000

This paper presents the behavior and strengthening effect of reinforced concrete rectangular beams strengthened using CFRP sheets with different strengthening level. In general, normally strengthened beams are failed by interfacial shear failure (delamination) within concrete, instead of by tensile failure of the CFRP sheets. The delamination occurred suddenly and the concrete cover cracked vertically by flexure was spalled off due to the release energy. The strengthened beams were stiffer than the control beam before and after reinforcement yielding. The ultimate load considerably increased with an increase of strengthening level, while the ultimate deflection significantly decreased. The tensile force of CFRP sheets and average shear stress of concrete at delamination failure were curvilinearly proportional to the strengthening level. Therefore, the increment of ultimate load obtained by strengthening was curvilinearly proportional to the strengthening level. The averaged horizontal shear stress of concrete at the interface ranges between (equation omitted) and (equation omitted) (in kg/$\textrm{cm}^2$) depending on strengthening level.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2000.04a
• /
• pp.781-786
• /
• 2000

This paper presents the behavior and strenghening effect of reinforced concrete rectangular beams strengthened sing CFRP sheets with different strengthening level. In general, normally strengthened beams are failed by interfacial shear failure (delamination) within concrete, instead of by tensile failure of the CFRP sheets. The delamination occurred suddenly and the concrete cover cracked vertically by flexure was spalled off due to the release energy. The ultimate load considerably increased with an increase of strengthening level, while the ultimate deflection significantly decreased. The tensile force of CFRP sheets and average shear stress of concrete at delamination failure were curvilinearly proportional to the strengthening level. Therefore, the increment of ultimate load obtained by strengthening was curvilinearly proportional to th strengthening level.

• Journal of the Korea Concrete Institute
• /
• v.16 no.5 s.83
• /
• pp.667-675
• /
• 2004

This paper presents the failure mode and strengthening design of reinforced concrete slab strengthened with Carbon Fiber Reinforced Polymer(CFRP) grid. Parameters involved in this experimental study are FRP grid reinforcement quantity, repair mortar thickness, the presence of anchor, and strengthening in compression. In this study, there are different failure types with increasing the CFRP grid strengthening reinforcement. On the low strengthening level, CFRP grid in repair mortar cover ruptures. On the moderate strengthening level, there is a debonding shear failure in the interface of carbon FRP grid because of the excessive shear deformation. On the high strengthening level, diagonal shear failure occurs. With the increasing of FRP grid reinforcement, the strengthening effect increased, but the ductility decreased. By limiting the strengthening level, it can be achieved to prevent shear failure which result in sudden loss in the resisting load capacity. CFRP rupture failure is desirable, because CFRP ruptured concrete slab keeps the same load capacity and ductility haying before strengthening even after failure. Finally, design guideline and procedure are given for strengthening of concrete slab with CFRP grid.

• Journal of the Korean Society of Physical Medicine
• /
• v.2 no.1
• /
• pp.31-39
• /
• 2007

Purpose : The main purpose of this study was to investigate the influence of lower extremity strengthening on balance ability of knee osteoarthritis. Methods : The walking exercise group with modality treatment and strengthening exercise group with modality treatment. The walking exercise and strengthening for 40 minutes per day and three times a week during 6 weeks period. Short Form McGill Pain Questionnaire(SFMPQ) was used to measure patient's pain level. Patient Specific Functional Scale(PSFS) was used to measure patient's functional disability level. BPM was used to measure sway area. Global Perceived Effect Scale(GPES) was used to measure recovery or worse of patient's condition. Results : 1. SFMPQ was strengthening exercise group showed significantly decreased more than walking exercise group(p<.05). 2. PSFS was strengthening exercise group showed significantly increased more than walking exercise group(p<.05). 3. Sway area was strengthening exercise group showed significantly limited area more than walking exercise group(p<.05). 4. GPES was strengthening exercise group showed significantly increased more than walking exercise group(p<.05). Conclusion : This study will be used as exercise method of patient with osteoarhtritis.

• PNF and Movement
• /
• v.19 no.1
• /
• pp.57-65
• /
• 2021

Purpose: This study investigated the effects of proprioceptive neuromuscular facilitation (PNF) respiratory muscle strengthening exercise on the pulmonary function, back pain, and disability level of patients with chronic low back pain (CLBP). Methods: There were 24 CLBP patients randomly divided into the experimental group (n = 12) who took part in PNF respiratory muscle strengthening exercise and the control group (n = 12) who performed a mock treatment. Both groups performed their respective interventions for 15 min five times per week for four weeks. The pulmonary function was measured using a portable spirometer. The back pain of the participants was assessed using a visual analogue scale. The Oswestry disability index was conducted to measure disability level. A paired t-test was performed to compare within-group changes before and after the PNF respiratory muscle strengthening exercise. Differences between the experimental and the control groups were analyzed using an independent t-test. For all tests, the level of statistical significance was α = 0.05. Results: The within-group change in pulmonary function was significantly different in the experimental group (p < 0.05), and the levels of back pain and disability were significantly different between the groups (p < 0.05). There was also a significant between-group difference in pulmonary function, back pain, and disability level after intervention (p < 0.05). Conclusion: These results suggest that PNF respiratory muscle strengthening exercise enhances pulmonary function and reduces levels of back pain and disability in patients with CLBP.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.11a
• /
• pp.251-254
• /
• 2005

This study will have to define the shear strengthening effects of steel fiber in beam and column levels, as well as to suggest estimation method of maximum shear capacity of structural members. From review of literature surveys and perform structural member test results, following conclusion can be made; In beam level, steel fiber strengthening factor is suggested from the tensile splitting test results and beam test results. After suggesting shear capacity of beam without stirrups and beam with stirrups by proposed steel fiber strengthening factor, proposed equation is possible to evaluate the shear capacity of beam. In column level, with column test results and proposed steel fiber strengthening factor, shear capacity equation of steel fiber reinforced concrete in column is suggested.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.11a
• /
• pp.13-14
• /
• 2012

This study investigates the effect of adhesive type applying to surface-strengthening Ondol floor on level of attachment. Adhesive materials of four types produced in different companies were prepared and their attaching performance was examined. Test results showed that the water-based epoxy type produced in S company was the most effective on attaching the pieces of the surface-strengthening Ondol floor product.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1993.10a
• /
• pp.546-550
• /
• 1993

Three basic experiments in agricultural machinery management , strengthening the construction of socialized service system, facilitating the two-level management system in rural areas and carrying through the principle of " paid service ' are described and the main methods of strengthening agricultural machinery management are developed in this paper.aper.

• Journal of the Korean Society of Physical Medicine
• /
• v.1 no.1
• /
• pp.13-21
• /
• 2006

Purpose : The main purpose of this study was to investigate the influence of muscle strengthening exercise on balance ability of knee osteoarthritis. The subject were consisted of 30 women patients with knee osteoarthritis. Method : The strengthening exercise group with modality treatment. The strengthening exercise for 40 minutes per day and three times a week during 6 weeks period. Short Form McGill Pain Questionnaire(SFMPQ) was used to measure patient's pain level. Patient Specific Functional Scale(PSFS) was used to measure patient's functional disability level. BPM was used to measure sway area. Global Perceived Effect Scale(GPES) was used to measure recovery or worse of patient's condition. Results : 1. SFMPQ was muscle strengthening exercise showed significantly decreased more than before treatment(p<.05). 2. PSFS was muscle strengthening exercise showed significantly increased more than before treatment (p<.05). 3. Sway area was muscle strengthening exercise showed significantly limited area more than before treatment(p<.05). 4. GPES was muscle strengthening exercise showed significantly increased more than before treatment(p<.05). Conclusion : This study will be used as exercise method of patient with osteoarhtritis.

• Physical Therapy Korea
• /
• v.27 no.1
• /
• pp.19-29
• /
• 2020

Background: Stretch-oriented home exercise programs are often used as treatments for patients with adhesive capsulitis; however, there is lack of research on home exercise programs to strengthen rotator cuffs. Objects: The aim of this study is to investigate the effect of home exercise programs for rotator cuff strengthening on pain, range of motion (ROM), disability level, and quality of life in patients with adhesive capsulitis. Methods: Twenty-two patients with adhesive capsulitis volunteered to participate in this study. The subjects were randomly divided into an experimental group (n = 11) and control group (n = 11). For the experimental group, manual therapy and home exercise programs for rotator cuff strengthening were applied for 6 weeks; for the control group, only manual therapy was applied for 6 weeks. Shoulder pain (quadruple visual analogue scale, QVAS), ROM, disability (shoulder pain and disability index-Korean version, SPADI), and quality of life (world health organization quality of life scale-Korean version, WHOQOL-BREF) were evaluated at baseline, after 3 weeks, and after 6 weeks of intervention. The changes in the measurement variables were analyzed by using repeated measure analysis of variance. Results: Significant differences were observed between the experimental group and control group in the QVAS; SPADI-pain scores; SPADI-disability scores; SPADI-total scores; flexion, abduction, internal and external rotation ROM of the glenohumeral joint; and WHOQOL-BREF total, overall, physical health, and psychological scores. All groups displayed statistically significant improvements as observed in the QVAS, SPADI, flexion, abduction, external and internal rotation ROM of the glenohumeral joint, and WHOQOL-BREF. Conclusion: Home exercise programs for rotator cuff strengthening had a positive impact on shoulder pain, shoulder ROM, disability level, and quality of life in patients with adhesive capsulitis. Therefore, we propose the use of home exercise programs for rotator cuff strengthening in the exercise rehabilitation of patients with adhesive capsulitis.