• Proceedings of the Korea Concrete Institute Conference
• /
• 2001.11a
• /
• pp.991-996
• /
• 2001

The strengthening of concrete structures in situ with externally bonded fiber sheets is increasingly being used for repair and rehabilitation of existing structures. Because fiber sheets is attractive for this application due to its good tensile strength, resistance to corrosion, and low weight. But, debonding failure may occur at the beam ends that fiber sheet bonded to the soffit of a beam. The method which can prevent debonding failure is suggested and proved its efficiency by using CPS experimental test. And this paper summarized the results of experimental studies concerning the end-anchorage system. Results show that the suggested method is faithful in strengthening with CFS.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.11a
• /
• pp.495-498
• /
• 2005

It was investigated the durability of the concrete to improve construction materials with polymer cement mortar in this study. With the popularity of repair and rehabilitation material, some mixtures composed of Ethylene Vinyl Acetate(EVA) was studied. Ethylene Vinyl Acetate(EVA) carried out tests to determine its properties which a include: freezing-thawing resistance test, carbonation test, and chemical resistance test. Result of freezing-thawing resistance test, mass change ratio and chemical resistance test, mass change ratio decreased of 12 and $15\~45\%$ as compared with control mortar. Carbonation depth decreased $3.7\~5.6mm$ as polymer-cement ratio increased $1\~4\%$.

• Journal of Magnetics
• /
• v.17 no.1
• /
• pp.68-71
• /
• 2012

Acute injuries to skeletal muscles can lead to significant pain and disability. Muscle pain results in muscle weakness and range of motion (ROM) decreases. Pulsed electromagnetic fields (PEMF) promote tissue repair, healing rates and reduce musculoskeletal pain. The results of many previous studies suggest that PEMF can contribute to chronic pain reduction, particularly in musculoskeletal injurys. However, we do not have enough information of its effects compared to a placebo. The principal objective of this study was to investigate differences in acute pain induced by the direct destruction of muscle tissue (extensor digitorum) with varying times of the application of PEMF, measured through the expression of c-fos on the spinal cord. Significant reduction of pain was found in groups exposed to PEMF and the group exposed to PEMF immediately after muscle injury showed the most significant differences. In conclusion, PEMF may be a useful strategy in reducing acute pain in muscle injury.

• Clinics in Shoulder and Elbow
• /
• v.23 no.2
• /
• pp.109-117
• /
• 2020

Repair of the rotator cuff tear is a joint-tightening procedure that can worsen joint stiffness. This paradoxical phenomenon complicates treatment of rotator cuff tear with joint stiffness. As a result, there is controversy about how and when to treat joint stiffness. As many treatments have been published, this review discusses the latest findings on treatment of rotator cuff tear with joint stiffness.

• Journal of Korean Physical Therapy Science
• /
• v.9 no.3
• /
• pp.129-140
• /
• 2002

This study intended to find out how the handicapped use medical aid, their satisfaction at using it and so on. First a preliminary survey(Apr. 20$\sim$24, 2002) was made for the handicapped who had been cured for rehabilitation by wearing medical aid at hospitals and welfare center in Jeonbuk region. Then total 120 subjects were asked to fill out a standardized questionnaire from May 15$\sim$22, 2002. Out of total 95 questionnaires collected, 84 questionnaires were analyzed except for 11 cases unsuitable for the intention of this study. The results can be outlined as follows: 1. In general characteristic, it was found that the causes of disability included disease(35 respondents; 41.7%), traffic accident(23 respondents, 27.4%) and so on. In addition, 1st handicap comprised the majority(32 respondents; 58.2%) in handicap grade and ankle foot orthosis(or b-k orthosis) was most often used as medical aid(28 respondents: 33.3%) 2. In particular, it was also shown that the 1st handicap mainly resulted from traffic accident(15 respondents, 27.3%) and post-disease disability (11 respondents, 20.0%). They wore medical aid for 1 year or less on the average, because they were hospitalized for cure, which showed statistically significant level(P<0.05). 3. It was found that total 69 respondents(82.1%) were more or less satisfied with their medical aids depending on the causes of disability, and total 46 respondents(83.6%) were satisfied with their aids according to their handicap grade, but there were no statistical significance. 4. Total 56(66.7%) respondents answered that they would purchase medical aid on their own expenses, when they became handicapped. And the price of medical aid ranged from $\300,000{\sim}400,000$(25 respondents: 29.8%) to \ 500,000 or more(24 respondents: 28.6%). It means that they purchased more or less expensive medical aid on their own expenses, which showed statistical significance(P<0.05). 5. If there was any failure of medical aid, 9 respondents(37.5%) answered that they would be serviced from medical companies, and 7 respondents(29.2%) would be serviced from medical aid manufacturers. Most respondents were serviced for their medical aids from related companies. For the question about the causes of dissatisfaction upon repair service, 11 respondents(45.8%) answered that existing service company provided unskilled repair services and other respondents answered that there was no spare part or higher service expenses than they thought. These answers had the statistical significance(P<0.05). However, 20 respondents(79.2%) answered that they were satisfied with the repair service, which means that most respondents are satisfied with the service. In view of the results as described above, it can be concluded that their handicap or disability results from disease or sequelae after traffic accident and most of the affected wear their own medical aid. In the future, it is required that the medical insurance should cover those medical aids, and the service for failed medical aids should be commissioned by technical serviceman to realize customized manufacture and repair service according to different causes so that the handicapped can enjoy more or less comfort and convenience in their daily lives without any extreme difficulty.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2000.10a
• /
• pp.269-277
• /
• 2000

This paper describes a seismic design procedure for steel moment connections with welded straight haunch. Recent test results showed that welding a straight haunch beneath the beam could be a viable solution for not only repair and rehabilitation of pre-Northridge moment connections but also new construction. Although a design procedure for the connection with triangular welded haunch has been developed recently, it is not applicable for the straight haunch moment connection because the force transfer mechanism is different. A simplified analytical model that considers the force interaction and deformation compatibility between the beam and haunch is briefly presented first based on the writer`s previous study. A generic design procedure as well as details that minimize the stress concentration at the haunch tip are also recommended.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.11a
• /
• pp.61-64
• /
• 2005

Recently to repair the structure of deteriorated concrete, LMC rehabilitation method is introduced. however, this method has the possible risks of brittle failure depending on bond performance of the interface. the prediction of interfacial behavior becomes essential to protect the failure. all of the studies which have been done about this field are only about material property such as strength, durability, bond. there is not enough data and studies about structural behavior and numerical analysis. therefore, in this study A flexural nonlinear analysis model of ABAQUS was proposed to predict the load-deflection response, interfacial stress, and ultimate strength. The parameter study showed that overlay thickness was a main influencing factor to the behavior of RC beam overlayed by LMC.

• Journal of the Korea Construction Safety Engineering Association
• /
• s.52
• /
• pp.58-66
• /
• 2011

This study presents an algorithm to select the best alternative plane among various bridge superstructure types (Steel box girder, Rational girder, PSC-I girder) using Value Engineering (VE). Economical efficiency, landscape, constructability, maintenance, stability, function of bridge superstructure were taken into consideration in the designing of bridge. Economical efficiency was evaluated for each alternative plan with optimal design considering Life Cycle Cost (LCC), Repair and rehabilitation histories and some factors were set to get reasonable results. In the application of Analytic Hierarchy Process (AHP), consistency of Pairwise Comparisons Matrix was evaluated and the best plan was determined.

• Composites Research
• /
• v.19 no.1
• /
• pp.43-48
• /
• 2006

High performance fiber reinforced cement composites have better performances than traditional cement based materials, therefore, have been expected as new construction applications such as the materials for construction & bridge structure, repair and rehabilitation applications, anti-collapse applications, anti-noise applications etc. However, they have lots of the problems such as material design, fabrication method and structural analysis. Also, the most serious problems of High performance fiber reinforced cement composites have been expensive initial cost, lack of long-term exposure data. As a result, it is needed that the efforts for lowering the initial cost and accumulation of long-term exposure. There has been hardly assessment results of life cycle cost for HPFRCC in construction field, but some papers showed that total life cycle cost could be profitable if the initial cost could be reduced.

• Journal of the Korean Society of Safety
• /
• v.17 no.2
• /
• pp.85-91
• /
• 2002

A research on the performance of retrofit anchors was conducted using adhesives for rehabilitation. From the pull-out tests of the chemical anchors, the effect of the hole diameter, spacer, temperature, moisture, embedment depth, and aging time were investigated. The spacer did not directly increased the pull-out load hilt increased post-yielding resistance therefore the ductility of the retrofit anchors. When the hole was cleaned and dried after the immersion, the pull-out load was greatly increased compared to the wet hole. A design equation was unposed depending on the embedment depth of the anchor bolt.