• Computers and Concrete
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• 제24권5호
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• pp.413-422
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• 2019

In this study, 3D Meso-scale finite-element model is presented to study the mechanical behavior of steel microfiber-reinforced polymer concrete considering the random distribution of fibers in the matrix. The composite comprises two separate parts which are the polymer composite and steel microfibers. The polymer composite is assumed to be homogeneous, which its mechanical properties are measured by performing experimental tests. The steel microfiber-polymer bonding is simulated with the Cohesive Zone Model (CZM) to offer more-realistic assumptions. The CZM parameters are obtained by calibrating the numerical model using the results of the experimental pullout tests on an individual microfiber. The accuracy of the results is validated by comparing the obtained results with the corresponding values attained from testing the steel microfiber-reinforced polymer concrete incorporating 0, 1 and 2% by volume of microfibers, which indicates the excellent accuracy of the current proposed model. The results show that the microfiber aspect ratio has a considerable effect on the mechanical properties of the reinforced polymer concrete. Applying microfibers with a higher aspect ratio improves the mechanical properties of the composite considerably especially when the first crack appears in the polymer concrete specimens.

• Steel and Composite Structures
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• 제4권4호
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• pp.265-280
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• 2004

In view of the mounting cost of rehabilitating deteriorating infrastructure, further compounded by intensified environmental concerns, it is now obvious that the evolvement and application of advanced composite structural materials to complement conventional construction materials is a necessity for sustainable construction. This study seeks alternative fill materials (polymer-based) to the much-limited cement concrete used in concrete-filled steel tubular structures. Polymers have been successfully used in other industries and are known to be much lighter, possess high tensile strength, durable and resistant to aggressive environments. Findings of this study relating to elasto-plastic characteristics of polymer concrete filled steel composite beams subjected to uniform bending highlight the enormous increase in stiffness, strength and ductility of the composite beams, over the empty steel tube. Moreover, polymer based materials were noted to present a wide array of properties that could be tailored to meet specific design requirements e.g., ductility based design or strength based design. Analytical formulations for design are also considered.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.585-590
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• 2001

The structural characteristics of concrete-filled glass fiber reinforced polymer tubes were studied. The concept of concrete-filled composite columns was introduced to overcome the corrosion problems associated with steel and concrete piles under severe environments. Other benefits of composite columns include low maintenance cost, high earthquake resistance, and long expected endurance period. Several experiments were conducted; 1) compression test for short-length composite columns, 2) uniaxial compression tests on a total of 7 columns with various slenderness ratios. Short-length columns give higher strength and ductility revealing high confinement action in concrete. Failure strengths, failure patterns, confinement effects, and stress-strains relations were analyzed for slender columns. Current study will show the feasibility of concrete-filled glass fiber reinforced polymer composite columns in corrosive environments, and will provide an experimental database for columns that are externally reinforced by multidirectional fibers.

• 한국농공학회논문집
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• 제46권6호
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• pp.37-45
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• 2004

In this study, twelve different glass fiber reinforced polymer concrete composite panel specimens with various rib heights and tensile side and reinforced side thickness were produced, and the flexural tests were conducted to figure out the effect of The height and thickness influencing on the flexural properties of composite panel. Test results of the study are presented. Especially, a prediction equation of the ultimate moment based on the strength design method agrees well with the test results, and it is thought to be useful for the corresponding design of cross-section according to various spans as the glass fiber reinforced polymer concrete composite panel is applied for a permanent mold.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.822-827
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• 2003

This study was performed to evaluate the internal and external factors affecting external strength of the 3-layer polymer composite pipes made of polymer mortar and fiber-glass reinforced plastic. Twenty four sandwich type 3-layer polymer composite pipes were made of polymer mortar and fiber-glass reinforced plastic by centrifugal method. The objective of this study was to evaluate the effects the of polymer mortar thickness for and core fiber-glass contents per unit area on external strength of 3-layer polymer composite pipes. For the more economical and practical design of 3-layer polymer composite pipe, further study should be done for the various polymer mortar, fiber-glass and different ratio of the inside/outside FRP thickness.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1992년도 봄 학술발표회 논문집
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• pp.67-73
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• 1992

Polymer-Impregnated Concrete(PIC) is a new polymer-concrete composite material which consist of basic cement concrete and polymer. The mechanical properties and behavior of PIC depend on the type of polymers and the impregnation techniques. In general, the polymer impregnation can improve the strength, durability and ductility of normal concrete. The objective of this study is to develop the analytical procedure for analyzing the structural responces of polymer-impregnated concrete beams with different polymer loading by using finite element method on the basis of experimental results.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1992년도 가을 학술발표회 논문집
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• pp.63-69
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• 1992

Research trends of concrete-polymer composite were analyzed based on 549 papers that were presented at international Congresses on Polymer in Concrete that have been opened seven times all around world since 1975. The analysis revealed that relative quantities of the papers about PC, PCC, PIC and others were 51%, 24%, 13% and 12%, in the order. Basic research was the main stream for PCC, PC, PIC. In PC study, however, it was shown that many researches were actively performed for application of PC.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.687-692
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• 2003

In this study, durability of concrete whose surface were treated by nano-composite hybrid polymer type coatings, which can provide a barrier against the ingress of moisture or aggressive ions to concrete, is discussed. For the durability evaluation of the coated concrete, chloride ponding test, accelerating carbonation test, porosity measurement test, and the SEM test are conducted. As the result of this study, it is found that nano-composite hybrid polymer type coated concrete has a much higher resistance to the ingress of chloride ion, carbon dioxide, moisture and aggressive acid than plain concrete has.

• Steel and Composite Structures
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• 제32권1호
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• pp.21-35
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• 2019

This study investigates the flexural behavior of steel-concrete composite beams strengthened with prestressed carbon fiber-reinforced polymer (CFRP) plates. An innovative mechanical anchorage system was developed. The components of the system can be easily assembled on site before applying a prestressing force, and removed from the structures after strengthening is completed. A total of seven steel-concrete composite specimens including four simply supported beams strengthened at the positive moment region and three continuous beams strengthened at the negative moment region were tested statically until failure. Experimental results showed that the use of prestressed CFRP plates enhanced the flexural capacity and reduced the mid-span deflection of the beams. Furthermore, by prestressing the CFRP laminates, the material was used more efficiently, and the crack resistance of the continuous composite specimens at the central support was significantly improved after strengthening. Overall, the anchorage system proved to be practical and feasible for the strengthening of steel-concrete composite beams. The theoretical analysis of ultimate bearing capacity is reported, and good agreement between analytical values and experimental results is achieved.

• 공업화학
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• 제20권1호
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• pp.67-74
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• 2009

오늘날 대규모 건설사업에 따른 골재의 고갈과 환경보호 측면에서 폐콘크리트 순환골재의 재활용이 절실히 요구되고있다. 폐콘크리트 순환골재를 재활용한 폴리머 복합재료를 개발하기 위하여 순환골재의 치환율을 5단계로 변화시키고(0, 25, 50, 75, 100%) 또 폴리머-시멘트비도 5단계로 변화시켜(0, 5, 10, 15, 20%) 총 25종류의 공시체를 제조하였다. 공시체의 제 성능을 조사하기 위하여 공시체의 압축 및 휨강도, 흡수시험, 내열수성시험, 총세공량 및 공극률에 대하여 조사하였다. 시험결과, 폴리머 복합재료의 물성은 폴리머 시멘트비의 증가에 따라 현저히 증가되었으나 폐콘크리트 순환골재의 치환율 증가에 따라서는 크게 저하되었다.