슬러리법에 의한 탄소섬유보강 시멘트복합체의 제조에서 보강섬유와 계면결착제와의 상관특성

최응규,Choi, Eung-Kyoo 한국건축시공학회 2002 한국건축시공학회지 Vol.2 No.3

The objective of the study is to examine the characteristic correlations between reinforcing carbon fiber and interfacial adhesion agent since the interfacial adhesion strength between reinforcing carbon fiber and matrices is believed to be an essential element influencing the physical properties in carbon fiber reinforced cement composite using slurry method. The integrity of interfacial adhesion between reinforcing fiber and cement not only affects the quality of fiber reinforced cement composite but also influences to a large degree the physical properties of the cement composite when producing carbon fiber reinforced cement composite using slurry method. Having analyzed the physical properties 1.e., water content, tensile strength, flexural strength and flexural toughness of carbon fiber reinforced cement composite specimens, C-PAM(cation polyacrylamide) was determined to be an optimum interfacial adhesion agent. The study has also demonstrated that interfacial adhesion strength varies largely on the content and type of the reinforcing fiber. Judging from magnified view of the tensile shear cross-section using VMS(video microscope system), interfacial adhesion strength between reinforcing fiber and matrices is affected by the type of interfacial adhesion agent. According to the result of the experiments, C-PAM was determined to be an ideal interfacial adhesion agent when using carbon fiber in producing carbon fiber reinforced cement composite with the optimum content of carbon fiber being established.

무기질섬유 계면처리에 따른 무기섬유강화 시멘트복합체의 계면결착특성에 관한 연구

최응규(Choi Eung-Kyoo),김연희(Kim Yeon-Hee) 대한건축학회 2009 大韓建築學會論文集 : 構造系 Vol.25 No.3

The purpose of this study was to present surface adhesion characteristics of inorganic fiber-reinforced cement composite based on the results of experiment on the cement composite by the interfacial agent for the inorganic fiber PAM (Polyacrylamide). To improve surface adhesion between the inorganic fiber and cement in the inorganic fiber-reinforced cement composite, N-PAM (Nonion), C-PAM (Cation) and A-PAM (Anion), etc. were used as interfacial adhesives. Analysis of the physical properties of inorganic fiber-reinforced cement composite showed that C-PAM adhesive is an optimal interfacial treatment agent for the carbon fiber, whereas A-PAM adhesive is optimal for the epoxy coating carbon fiber. The excellent interfacial adhesion and physical properties of the cement composite were likewise revealed. Besides, the study of the tensily crushed cross section of the cement composite showed that the cement composite using interfacial treatment of the inorganic fiber manifests excellent refinement in the inner structure and interfacial adhesion, along with improved relevant physical properties. Results showed that the epoxy coating carbon fiber has better interfacial adhesion than the carbon fiber. When interfacial adhesion is reinforced by the interfacial adhesive for inorganic fiber, C-PAM was found to be suitable for the carbon fiber, whereas A-PAM adhesive was suitable for the epoxy coating carbon fiber. Analysis of the physical properties of inorganic fiber-reinforced cement composite showed that the epoxy coating carbon fiber has stronger interfacial adhesion to the cement interfacial structure, and better physical characteristics and mechanical properties than the carbon fiber.

목재펄프의 특성 및 함량이 무기섬유보강 시멘트복합체의 내부구조 및 물성에 미치는 영향연구

최응규(Choi Eung-Kyoo),김옥규(Kim Ok-Kyue),양극영(Yang Keek-Young) 대한건축학회 2004 大韓建築學會論文集 : 構造系 Vol.20 No.4

The objective of the study is to suggest a suitable woodpulp material and its optimum content applicableto carbon<br/> fiber-reinforced cement composite. Following selection of a suitable carbon fiber within a range of inorganic fiber materials, a<br/> series of experiments has been carried out to analyze the effects of varying woodpulp contents and its characteristics in cement<br/> composite with respect to physical and mechanical properties.<br/> The experiments have demonstrated that fibrin and fibril in the woodpulp play important roles in the inorganic fiber-reinforced<br/> cement composite using carbon fiber; moderates inherent brittleness: disperses fibers uniformly: maintains the consistency of the<br/> mixture. Analyzing the properties of carbon fiber-reinforced cement composite in relation to the varying contents of woodpulp, the<br/> fibrin content in the woodpulp had significant effect upon the physical properties. In addition, the degree of fibrilization of<br/> woodpulp determines the mechanical properties. In brief, softwood pulp having tougher fibers and broader fibrin with rich<br/> fibrilization demonstrated better mechanical performance in the cement matrix. Observing the interfacial failure plane, while<br/> excessive content of woodpulp in the cement matrix exhibited loose matrix structure with voids, 2.5% woodpulp content proved to<br/> be optimum showing compact matrix structure.<br/> Based on the result of the experiment, softwood pulp with rich fibrin content and well-developed fibrilization proved to be the<br/> optimum woodpulp for inorganic fiber-reinforced cement composite. Optimum physical properties were obtained at the ranges of<br/> 2.5% to 3.0% in the woodpulp content. When carbon fiber is used as reinforcingfiber, the most effective content of woodpulp in<br/> the mix to moderate brittleness of carbon fiber turned out to be approximately 3.0%.

무기섬유보강 시멘트복합체에서 계면결착제가 무기섬유계면에 미치는 영향

최응규(Choi Eung-kyoo),고성석(Go Seong-seok),김선국(Kim sun-kuk) 대한건축학회 2003 大韓建築學會論文集 : 構造系 Vol.19 No.4

The objective of the study is to examine the characteristic correlations between reinforcing inorganic fiber and interfacial adhesion agent since the interfacial adhesion strength between reinforcing inorganic fiber and matrices is believed to be an essential element influencing the physical properties in inorganic fiber reinforced cement composite using slurry method. The integrity of interfacial adhesion between reinforcing fiber and cement not only affects the quality of fiber reinforced cement composite but also influences to a large degree the physical properties of the cement composite when producing inorganic fiber reinforced cement composite using slurry method. IIaving analyzed the physical properties i.e., water content, tensile strength, flexural strength and flexural toughness of inorganic fiber reinforced cement composite specimens, C-PAM(cation polyacrylamide) was determined to be an optimum interfacial adhesion agent. The study has also demonstrated that interfacial adhesion strength varies large]y on the content and type of the reinforcing fiber. Judging from magnified view of the tensile shear cross-section using VMS (video microscope system), interfacial adhesion strength between reinforcing fiber and matrices is affected by the type of interfacial adhesion agent. According to the result of the experiments, C-PAM was determined to be an ideal interfacial adhesion agent when using carbon fiber in producing inorganic fiber reinforced cement composite with the optimum content of carbon fiber being estabJished.

유기질섬유 계면처리에 따른 유기섬유강화 시멘트복합체의 계면구조특성 및 물성고찰

최응규(Choi Eung-Kyoo) 대한건축학회 2003 大韓建築學會論文集 : 構造系 Vol.19 No.8

The aim of the study is to analyze physical and mechanical properties of cement composite specimens by way of adding varying contents of a selected range of Polyacrylamides(PAMs) as interfacial coupling agent for organic fibers. In line with the aim of the study, mode of failure has also been carefully examined. Based on the experiment, the study attempts to suggest a characteristic of interfacial structure matrix and physical properties of organic fiber-reinforced cement composite. In the experiment, N-PAM(Nonion), C-PAM(Cation) and A-PAM(Anion) were used as interfacial coupling agent for organic fibers such as PVA and acrylics. The experiment has demonstrated A-PAM for PVA fibers and C-PAM for acrylic fibers to be an optimum interfacial coupling agent for the respective organic fibers in terms of both interfacial adhesion and physical properties. When an inappropriate interfacial treatment agent was used, a number of organic fibers were found to have been pulled out and the matrices were found to be loose. It is evident from the experiment that there is an optimal PAM as interface treatment agent for respective organic fibers, producing high degree of compactness of the matrix as well as excellent physical properties including interfacial adhesion. The experiment has demonstrated that when PVA fibers are treated with A-PAM and acrylic fibers with C-PAM, PVA fibers proved to be superior to acrylic fibers in terms of adhesion to cement matrix as well as in terms of physical and mechanical properties.

보강섬유와 시멘트와의 매트릭스(Matrix) 구조에서 계면가교제가 계면결착에 미치는 특성

최응규(Choi Eung-kyoo) 대한건축학회 2003 大韓建築學會論文集 : 構造系 Vol.19 No.7

It is necessary to reinforce the interfacial adhesion between components in fiber reinforced cement composite either by surface treatment thereby producing interfacial attraction or by reinforce the interfacial adhesion between organic and inorganic materials by means of coupling agent. The objective of the study is to propose a practical approach in selecting a suitable interfacial coupling agent for an assorted reinforcing fiber and cement compounds and to determine the most appropriate coupling agent for a particular combination. The experiment analyzed the integrity of the interfacial adhesion by means of VMS(video microscope system) as well as by measurement of interfacial adhesion, demonstrating polyacrylamide, a polymeric coupling agent, being the most effective coupling agent for the purpose of reinforcing the interfacial adhesion between reinforcing fiber and cement. There are three different kinds of PAM depending on the ionization; N-PAM, A-PAM and C-PAM, each reinforcing fiber material having its own optimum PAM. The experiment has demonstrated that N-PAM was least effective for all the reinforcing fibers used in the analysis. While A-PAM coupling agent was most effective in PVA fibers, C-PAM proved to be the most effective coupling agent in both acrylic and carbon fibers.

섬유강화 시멘트복합체에서 목재해면펄프가 섬유분산고착 및 계면구조에 미치는 영향

최응규(Choi Eung-Kyoo),이재용(Lee Jae-Yong),이찬식(Lee Chan-Sik) 대한건축학회 2004 大韓建築學會論文集 : 構造系 Vol.20 No.5

The aim of the study is to analyze characterized dispersion and arrangement of reinforcing fibers within cement composites<br/> among various reinforcing fiber materials, and to analyze physical and mechanical properties of cement composite specimens when<br/> the content of wood pulp is brought up to 4.0%. Based on the result of the experiment, the study is also to examine the effects<br/> of wood pulp on interfacial matrix and physical properties of cement composite and to determine optimal wood pulp material to be<br/> used for cement composite.<br/> Having analyzed the effects of wood pulp upon interfacial matrix and physical properties of cement composite, softwood pulp<br/> has demonstrated excellent interfacial adhesion and mechanical properties due to presence of abundant fibroids and fibrillation.<br/> While recycled sulfite wood pulp has exhibited relatively poor mechanical properties as compared to softwood pulp because of low<br/> tensile strength of the pulp fibers, hardwood pulp has demonstrated the poorest mechanical properties due to low content of fibers<br/> and brittleness. The study has demonstrated softwood pulp to be the most suitable material in terms of physical properties of<br/> cement composite for the purpose of reinforcing and dispersion of fibers.<br/> Because of the excellent hydrophilic and coagulating characteristics in water, wood pulp is proved to be an effective agent for<br/> uniform dispersion and maintaining the consistency of reinforcing fibers regardless of its kind. Whereas softwood pulp proved to<br/> be the most superior material, recycled sulfite wood pulp may be preferred in terms of economy with reasonable physical<br/> properties.

실험적 마우스결핵에 있어서 Isoniazid+Thiacetazone 병합요법에 대한 실험적 연구

최응규 ( Eung Kyoo Choi ) 대한결핵 및 호흡기학회 1971 Tuberculosis and Respiratory Diseases Vol.18 No.3

실험적 마우스결핵에 있어서 Isoniazid 단독 간혈요법에 관한 실험적 연구

최응규 ( Eung Kyoo Choi ),변해원 ( Hae Won Pyun ) 대한결핵 및 호흡기학회 1971 Tuberculosis and Respiratory Diseases Vol.18 No.1

폐결핵환자에서의 Rosette-Forming Lymphocytes수에 관한 연구

최응규 ( Eung Kyoo Choi ),변해원 ( Hae Won Pyun ),박태수 ( Tae Soo Park ),김희숙 ( Hye Sook Kim ) 대한결핵 및 호흡기학회 1977 Tuberculosis and Respiratory Diseases Vol.24 No.3