• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 추계 학술논문 발표대회
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• pp.152-153
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• 2014

Recently, there are many research for increasing tensile strength of concrete using fiber-reinforced mortar. Especially, the research about the high ductile concrete with fiber-reinforcement which behaves strain-hardening (defined as HPFRCC) is performed while it has the drawback of decreasing workability because of interruption of fibers such as fiber-ball effect. Hence to solve this problem, as a previous research, combination of metal fiber and organic fiber was suggested. Although this research achieved favorable result of workability of HPFRCC, the research scope was concentrated on workability of the mortar. Therefore, in this research, based on the fiber-combination of previous research, the tensile properties is evaluated depending on water-to-binder ratios to obtain improved tensile performance.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1992년도 제2차 학술발표초록집
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• pp.68-68
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• 1992

• 한국대기환경학회지
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• 제25권2호
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• pp.122-132
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• 2009

Adsorption of toluene by activated carbon fiber (ACF) coated with dielectric heating element and desorption by applying microwave were investigated. In order to prepare adsorbent so that VOC can be desorbed by microwave heating, fine dielectric heating element with nano size was coated on the surface of the ACF using hybrid binder. Eight adsorbents (ACF-DHE, Activated Carbon Fiber coated with Dielectric Heating Element) were prepared with different amount of dielectric heating element, kinds of hybrid binder, and solvent. In order to investigate adsorption characteristics, BET surface area, pore volume, and average pore size were measured for each adsorbent including ACF. Breakthrough experiments with toluene concentration, flow rate, bed length using fixed bed reactor were performed to investigate adsorbality of adsorbent, and results were compared with that of the ACF. Desorption reactor was constructed with modified microwave oven to investigate heating effect on ACF-DHE by applying microwave power. Each adsorbent saturated with toluene were put into desorption reactor. Composition of desorbed gas generated by applying controlled microwave power to reactor was measured. Up to now, hot air desorption method has been used. Experimental results showed that desorption method with new adsorbent prepared by coating dielectric heating element on ACF can be used for industrial application.

• 한국주조공학회지
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• 제15권2호
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• pp.138-145
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• 1995

The mechanical properties of $Al/Al_2O_3$ composites have been investigated in relation with manufacturing factors such as applied pressure of casting and binder amount of preform. It was found that tensile strength increases with an increase of applied pressure, but decreases with binder amount. Increase of tensile strength is attributable to refinement of microstructure, improvement of intefacial bonding between $Al_2O_3$ short fiber and matrix, decrease of porosity in the matrix. Due to the high thermal stability of alumina short fiber, tensile strength of composites at $150^{\circ}C$ was superior to matrix alloy at room temperature. To evaluate the strength of composites, modified Kelly-Tyson's equation was introduced. Manufacturing factor M was obtained calculating from experimental data. M values were increased with applied pressure, but decreased with binder amount. The initiation of microcrack appeared to be at interface and reinforcement colony. Amount of micro-dimple was increased with applied pressure, and interfacial debonding phenomenon was remarkable with an increase of binder amount.

• 콘크리트학회지
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• 제5권4호
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• pp.156-166
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• 1993

본 연구는 산업폐기물인 플라이애쉬를 충전재로 사용한 강섬유보강 폴리에스터 수지 복합체의 워커빌리티 및 그 역학적 특성을 구명하고, 그 제조방법을 실험적으로 검토한 것이다. 동복합체는 강섬유, 충전재(플라이애쉬, 중질탄산칼슘), 불포화 폴리에스터수지(스티타이렌 모노머), 경화촉진제(코발트옥테이트), 촉매(MEKPO) 및 굵은 골재와 잔골재를 사용하여 제조하였고, 배합조건별로 그 특성을 검토하였다. 연구결과, 플라이애쉬$\cdot$폴리에스터 수지복합체의 경우, 플라이애쉬-결합재비의 증가에 따라 압축, 인장, 휨강도 및 경화수축은 현저히 개선되었고 강섬유 보강 플라이애쉬$\cdot$폴리에스터 수지복합체의 경우 워커빌리티는 플라이해쉬-결합재비 및 강섬유혼입율 증가에 따라 저하하였으나, 압축, 휨강도 및 휨인성은 섬유혼입율 증가에 따라 현저히 증가되었다.

• 한국농공학회논문집
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• 제52권1호
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• pp.69-77
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• 2010

Research on permeable pavement like asphalt and concrete pavement with porous structure has been increasing due to environmental and functional need such as reduction of run off and flood, and increase and purification of underwater resource. This study was performed to evaluate permeability, strengths and durability of permeable polymer concrete (PPC) using recycled aggregate that is obtained from waste concrete. Also, 6mm length of polypropylene fiber was used to increase toughness and interlocking between aggregate and aggregate surrounded by binder. In the test results, regardless of kinds of aggregates and fiber contents, the compressive strength and permeability coefficient of all types of PPC showed the higher than the criterion of porous concrete that is used in permeable pavement in Korea. Also, strengths of PPC with increase polypropylene fiber volume fraction showed slightly increased tendency due to increase binder with increase of fiber volume fraction. The weight reduction ratios for PPC after 300 cycles of freezing and thawing were in the range of 1.6~3.8 % and 2.2~5.6 %, respectively. The weight change ratio was very low regardless of the fiber volume fraction and aggregates. The weight reduction ratios of PPC with fiber and aggregate were in the range of 1.3~2.7 % and 2.2~3.2 % after 13 weeks and was very low regardless of the fiber volume fraction and aggregates.

• Computers and Concrete
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• 제5권5호
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• pp.475-490
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• 2008

The paper explores the potential of applicability of Genetic programming approach (GP), adopted in this investigation, to model the combined effects of five independent variables to predict the mini-slump, the plate cohesion meter, the induced bleeding test, the J-fiber penetration value, and the compressive strength at 7 and 28 days of self-compacting slurry infiltrated fiber concrete (SIFCON). The variables investigated were the proportions of limestone powder (LSP) and sand, the dosage rates of superplasticiser (SP) and viscosity modifying agent (VMA), and water-to-binder ratio (W/B). Twenty eight mixtures were made with 10-50% LSP as replacement of cement, 0.02-0.06% VMA by mass of cement, 0.6-1.2% SP and 50-150% sand (% mass of binder) and 0.42-0.48 W/B. The proposed genetic models of the self-compacting SIFCON offer useful modelling approach regarding the mix optimisation in predicting the fluidity, the cohesion, the bleeding, the penetration, and the compressive strength.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
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• pp.321-322
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• 2013

Recently, the exhaustion of resource and environmental damage is serious due to the global warming because of the CO₂ exhaust and each type the natural aggregate picking described below. meanwhile, The rest is the actual condition gone to the dumping ground that there is nearly no use which the waste glass can recycle and it is recycled. This research applied the waste glass as the cement substitute material the inorganic binder and coares aggregate substitute material. It utilizes the substitute material of the cement according to it and natural aggregate and tries to develop the environment-friendly artificial stone. The inorganic binder used the blast furnace slag, red mud, and fly ash. The straight type steel fiber, PVA fiber, PA fiber, and cellulosic fiber were used with a kind of fiber. As to the experimental item according to it, the compressive strength is the flexural strength and compressive strength.

• 한국세라믹학회지
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• 제53권4호
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• pp.386-392
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• 2016

Heat insulation plates of fumed silica were prepared by mixing fumed silica, SiC powder and chopped glass fiber by a high speed mixer followed by pressing of the mixture powder in a stainless steel mold of $100{\times}100mm$. Composition of the plates, particle size of SiC, and type of inorganic binder were varied for observation of their contribution to heat insulation of the plate. The plate was installed on the upper portion of an electric furnace the inside temperature of which was maintained at $400^{\circ}C$ and $600^{\circ}C$, for investigation of heat transfer through the plate from inside of the electric furnace to outside atmosphere. Surface temperatures were measured in real time using a thermographic camera. The particle size of SiC was varied in the range of $1.3{\sim}17.5{\mu}m$ and the insulation was found to be most excellent when SiC of $2.2{\mu}m$ was incorporated. When the size of SiC was smaller or larger than $2.2{\mu}m$, the heat insulation effect was decreased. Inorganic binders of alkali silicate and phosphate were tested and the phosphate was found to maintain the heat insulation property while increasing mechanical properties.

• Computers and Concrete
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• 제34권2호
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• pp.213-230
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• 2024

The use of waste tires and industrial wastes such as fly ash (FA) and ground granulated blast furnace slag (GGBS) in concrete is an important issue in terms of sustainability. In this study, the effect of parameters affecting the physical, mechanical and microstructural properties of FA/GGBS-based geopolymer concretes with waste rubber fiber was investigated. For this purpose, the effects of rubber fiber percentage (0.6%, 0.9%, 1.2%), binder (75FA25GGBS, 50FA50GGBS, 25FA75GGBS) and curing temperature (75 ℃, 90 ℃ and 105 ℃) were investigated. The Taguchi-Grey Relational Analysis (TGRA) method was used to obtain optimum parameter levels of rubber fiber geopolymer concrete (RFGC). The slump, fresh and hardened density, compressive strength, flexural strength, static and dynamic modulus of elasticity, ultrasonic pulse velocity (UPV) tests and scanning electron microscopy (SEM) analysis were performed on the produced concretes. The analysis of variance (ANOVA) method was used to statistically determine the effects of the parameters on the experimental results. A confirmation test was performed to test the accuracy of the optimum values found by the TGRA method. With the increase of GGBS percentage, the compressive strength of RFGC increased up to 196%. The increase in rubber fiber percentage and curing temperature adversely affected the mechanical properties of RFGC. As a result of TGRA, the optimum value was found to be A1B3C1. ANOVA results showed that the most effective parameter on the experimental results was the binder with 99% contribution percentage. It is understood from the SEM images that the optimum concrete had a denser microstructure and less capillary cracks and voids. For this study, the use of the TGRA method in multiple optimization has proven to provide very useful and reliable results. In cases where many factors are effective on its strength and durability, such as geopolymer concrete, using the TGRA method allows for finding the optimum value of the parameters by saving both time and cost.