• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 가을 학술발표회 논문집
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• pp.355-360
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• 1995

A series of 15 reinforced concrete beams was tested to evaluate the flexural performance of the repaired RC beams. the key parameters for this study were the repair materials, polymer/cementitious materials, in addition to the strengthening material, steel plates and carbon fiber sheets. The repaired specimens failed by a typical flexural mode. showing minor interface failure. The results show that epoxy, polyester resins and latex modified cementitous mortars are effective for repairing the concrete beams. However, the flexural preformance of the strengthened beams are varied depending on the repaired materal.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 가을학술발표대회논문집
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• pp.47-48
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• 2023

Reinforced concrete structures are an integrated structure in which reinforcing bars are placed on the tensile side of the beam to compensate for concrete that is strong in compression but weak in tension, so that the concrete receives compressive force and the reinforcing bars receive tensile force. It is durable, fire-resistant, economical, and adapts to the shape and dimensions of the structure. It has been widely used for a long time because it can be made freely without restrictions. However, reinforced concrete structures have the disadvantage that cracks occur easily, so they are repaired using a cross-sectional construction method. During this process, problems such as the repair part falling off occurred, so in order to solve the problem, stress changes due to changes in the size of the repair part were examined. As a result, based on the elastic modulus ratio of 1.0, the stress tended to increase as the size of the repair part decreased when it was less than 1.0, and the opposite tendency was seen when it was more than 1.0. This is believed to be due to an increase in the area of the part with a large elastic modulus.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.785-792
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• 2000

Repair and retrofit system of concrete structures has been developed from conventional reinforced concrete overlaying, steel plate bonding and recently to fiber composite systems. Research and study on carbon, aramid, and glass fiber composite system has been actively carried out from all over the world Glass fiber composite is proved to be competitive technically and enconomically, among fiber composite system. CAF system is a system developed locally using all domestic materal, glass fabric and epoxy, and improved in shear bonding property by utilizing silica fume mixed with epoxy. All the tests on material properties, structural behavior, constructiveness at site and quality control procedure proved to be most appropriate system so far developed. Futher research work is and will be under progress for utilization of this system which will be applied to more adverse situation.

• 한국재료학회지
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• 제24권12호
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• pp.671-676
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• 2014

It is known that bones get damaged by accidents and aging. Since the discovery of Bioglass, various kinds of ceramics have been also found to bond to living bone; some of these ceramics are already being clinically used as bone-repairing materials. In the present study, antibacterial calcium silicate gel ($Ag-30CaO{\cdot}70SiO_2$ gel) was prepared by sol-gel method in order to control the microstructure, which is related to the dissolution rate and induction period of apatite formation in body environment. In addition, biological $Ag-30CaO{\cdot}70SiO_2$ is tested. This was done to impart antimicrobial activity to the $30CaO{\cdot}70SiO_2$. Ag ion was added during sol-gel synthesis to replace the $H_2O$ added during the making of the $30CaO{\cdot}70SiO_2$ gel, which has silver solutions of various concentration. After the sol-gel process, 1N-$HNO_3$ solution was used to wash the gel when synthesizing the gel, in order to maintain the porous structure and remove PEG, water soluble polymers. Then, the apatite forming ability of the sol-gel derived CaO-$SiO_2$ gels was investigated using simulated body fluid (SBF), which had almost the same ion concentration as that of human blood plasma. The gels were analyzed by FT-IR spectroscopy, SEM observation, XRD, and fluorescent microscopy. The apatite was successfully created even after washing the gel; apatite is present in an amorphous state, and was found to affect the concentration of the Ag ion in cells in MC3T3 live & dead assay results. From these results, it is suggested that a good material that can be used to repair defects of nature bone is $Ag-30CaO{\cdot}70SiO_2$ gel.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제20권2호
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• pp.133-138
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• 1998

23세의 건강한 산모에게서 정상 분만되고, 출생시 체중 3.lkg의 여자 아이가 출생 직후 청색증, 호홉 곤란 등의 소견을 보이나, 육안적으로 관찰되는 불완전 양측성 구순열 이외에는 특별한 두개안면 이형증 등의 소견은 관찰되지 않아서, 소아과 담당의사가 전비공을 통하여 비인두강 내의 분비물 등의 이물질 홉인을 시도하려다 작은 고무 도관의 삽입이 이루어지지 않아서 후비공 폐쇄를 의심하였다. 경구 호홉관을 이용하여 기도 확보 후에 후비공 폐쇄 여부의 진단을 위해서, 비강내 방사선 비투과성 물질의 접적 주입한 후에 방사선 사진, 컴퓨터 단층 촬영 등을 통하여 완전 골성 양측성 후비공 폐쇄를 확진하였다. 양측성 후비공 폐쇄는 출생시 주기적인 호홉 곤란의 증상을 보이며, 특히 포유시에 호홉 곤란의 증상이 악화되어서 신생아의 생명을 위협하는 응급 상황으로 이에 대한 외과적인 처치를 시행하기로 결정하였다. 후비공 폐쇄에 대한 외과적인 처치는 비강을 통한 접큰법, 구개부를 통한 접근법, 비중격을 통한 접근법 등의 여러 가지 접근법이 있으나, 본 환자의 경우는 완전 골성 양측성 후비공 폐쇄로 확진이 되었고, 이에 대한 저자들의 경험이 전혀 없는 상태이었기에 보다 좋은 수술 시야를 용이하게 확보할 수 있으며, 새로이 형성해준 후비공을 따라 점막 피판을 보존해 줄 수 있고, 수술 후 후비공의 개통성을 보다 확실하게 얻을 수 있을 것으로 예상되는 구개부를 통한 접근법을 이용하여 외과적인 처치를 시행하였다. 수술 후 약 1 년이 경과하였으나 임상적으로 호홉 곤란 등의 특별한 문제점이 없이 만족할 만한 경과를 보였다. 일반적인 교과서에서 설명하듯이 기성품으로 제작된 자가보전 견인자의 설압자는 이와 같은 신생아의 증례에서는 크기가 상대적으로 너무 커서 사용이 곤란하였다는 점을 염두에 두어야 할 것으로 생각되며, 추후 유사한 증례의 수술시에 도움을 주고자 매우 희귀한 증례인 완전 골성 양측성 후비공 폐쇄 환자에 대한 치험례를 문헌 고찰과 함께 보고하는 바이다.