• Advances in concrete construction
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• 제10권4호
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• pp.319-332
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• 2020

The impacts of reinforcing concrete matrix with steel fibers, polypropylene fibers and recycled plastic fibers using different volume fractions of 0.15%, 0.5%, 1.5% and 2.5% on the compressive and tensile characteristics are experimentally investigated in the current research. Also, flexural behavior of plain concrete (PC) beams, shear performance of reinforced concrete (RC) beams and compressive characteristics of both PC and RC columns reinforced with recycled plastic fibers were studied. The experimental results showed that the steel fibers improved the splitting tensile strength of concrete higher than both the polypropylene fibers and recycled plastic fibers. The end-hooked steel fibers had a positive effect on the compressive strength of concrete while, the polypropylene fibers, the recycled plastic fibers and the rounded steel fibers had a negative impact. Compressive strength of end-hooked steel fiber specimen with volume fraction of 2.5% exhibited the highest value among all tested samples of 32.48 MPa, 21.83% higher than the control specimen. The ultimate load, stiffness, ductility and failure patterns of PC and RC beams in addition to PC and RC columns strengthened with recycled plastic fibers enhanced remarkably compared to non-strengthened elements. The maximum ultimate load and stiffness of RC column reinforced with recycled plastic fibers with 1.5% volume fraction improved by 21 and 15%, respectively compared to non-reinforced RC column.

• 한국농공학회논문집
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• 제65권4호
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• pp.45-52
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• 2023

This study was conducted to examine the possibility of use as a structural material for ginseng cultivation facilities of recycled plastics. In order to determine the possibility that recycled plastic can replace timber used as a structural material for ginseng cultivation facilities, the specimens collected by elapsed time were compared with timber through bending tests. In addition, in order to analyze the effect of external environmental conditions on recycled plastic products, bending test was conducted with the specimens that had completed weathering test and accelerated heat aging test respectively. As a result, the bending strength of recycled plastic specimens with the elapsed time of 360 days was lower than that of timber. But bending strength of recycled plastic specimens exceeded the design allowable stress standard set by the Korea design standard (MOLIT, 2016). There was no degradation in quality of recycled plastic due to the external environment, and it was found that there would be no problem even if it was used as a structural material for ginseng cultivation facilities.

• 한국건설순환자원학회논문집
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• 제2권3호
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• pp.225-232
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• 2014

이 연구에서는 재활용 플라스틱 섬유 (recycled plastic fibers)로 보강된 콘크리트의 역학적 특성을 파악하고자 하였다. 부피비 0, 0.5, 1.0, 1.5 및 2.0%의 섬유비를 갖는 재활용 섬유보강 콘크리트의 역학특성 실험결과를 분석하였다. 섬유보강 콘크리트의 압축강도, 탄성계수, 인장강도와 길이변화 특성 실험을 수행하였다. 실험결과는 섬유비가 증가함에 섬유보강 콘크리트의 압축강도와 탄성계수는 증가하는 것을 나타낸다. 또한, 재활용 섬유보강 콘크리트는 일반콘크리트에 비해 쪼갬인장강도, 휨인장강도, 균열개구변위 및 길이변화에 우수한 특성을 나타낸다. 연구결과는 추후 재활용 플라스틱 섬유보강 콘크리트의 재료 모델을 위한 실제적인 기초실험자료로 활용될 수 있을 것으로 사료된다.

• 한국안전학회지
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• 제18권4호
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• pp.85-91
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• 2003

In this study, We have investigated leaching characteristics of heavy metals for recycled plastic composites containing EAF(Electric Arc Furnace) dust & EAF slag. EAF dust & EAF slag used that is generated in the 3 steel-making compaines in domestic. The physical and chemical properties of EAF dust & slag was examined by measuring specific surface area. porosity, oil absorption test and chemical wetting analysis etc. Results of total analysis indicated that EAF dust, slag contained significant amount of hazardous metals such as Cu, Pb, Cd and Cr. But, In the leaching test of the recycled plastic composites containing EAF dust, slag by Korean Standard Leaching Procedure, composites shows much lower leaching concentration of heavy metals. It was concluded that the recycled plastic composites containing EAF dust, slag showed good physical and chemical characteristics. This means that the EAF dust, slag can be effectively used as a functional filler.

• Environmental Analysis Health and Toxicology
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• 제28권
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• pp.13.1-13.5
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• 2013

Objectives: Potential environmental risks caused by chemicals that could be released from a recycled plastic product were assessed using a screening risk assessment procedure for chemicals in recycled products. Methods: Plastic slope protection blocks manufactured from recycled plastics were chosen as model recycled products. Ecological risks caused by four model chemicals - di-(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), cadmium (Cd), and lead (Pb)-were assessed. Two exposure models were built for soil below the block and a hypothetic stream receiving runoff water. Based on the predicted no-effect concentrations for the selected chemicals and exposure scenarios, the allowable leaching rates from and the allowable contents in the recycled plastic blocks were also derived. Results: Environmental risks posed by slope protection blocks were much higher in the soil compartment than in the hypothetic stream. The allowable concentrations in leachate were $1.0{\times}10^{-4}$, $1.2{\times}10^{-5}$, $9.5{\times}10^{-3}$, and $5.3{\times}10^{-3}mg/L$ for DEHP, DINP, Cd, and Pb, respectively. The allowable contents in the recycled products were $5.2{\times}10^{-3}$, $6.0{\times}10^{-4}$, $5.0{\times}10^{-1}$, and $2.7{\times}10^{-1}mg/kg$ for DEHP, DINP, Cd, and Pb, respectively. Conclusions: A systematic ecological risk assessment approach for slope protection blocks would be useful for regulatory decisions for setting the allowable emission rates of chemical contaminants, although the method needs refinement.

• 한국건축시공학회지
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• 제7권2호통권24호
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• pp.93-98
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• 2007

Waste of Plastic that is waste tile and waste interlocking block result, waste tile and waste interlocking block that execute an experiment to foretell practical use possibility availability as recycled aggregate for concrete giving change in the principal parts rate for coarse aggregate recycled aggregate appeared in the world by available thing to coarse aggregate to rate 10% but necessity that present amount used establishing material application standard that is crushed than uniform application standard to receive entropy of re-fresh concrete quality is judged to be.

• Composites Research
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• 제31권5호
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• pp.202-208
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• 2018

In this paper, mechanical and hygroscopic properties of teak sawdust and recycled polypropylene (RPP) composites are evaluated and compared with virgin polypropylene (VPP) matrix based composites. Verities of composites are prepared by variation in the plastic types, wood plastic ratio and the addition of coupling agent in the formulations. Mixing of wood sawdust and polypropylene is done by a twin screw extruder, and then sheets of wood plastic composites (WPCs) are produced by using the compression molding method. The results show that recycled matrix composites exhibit better tensile, flexural strength with low impact strength than virgin matrix based composites. Recycled composites show low water absorption and thickness of swelling than virgin matrix based composites. The results confirm that wood content in the polymer matrix affects the performance of composites while presence maleated polypropylene (MAPP) improves the properties of the composites significantly. Developed RPP matrix composites are as useful as VPP matrix composites and have the potential to replace the wood and plastics products without any adverse effect of the plastics on the environment.

• 콘크리트학회논문집
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• 제19권2호
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• pp.233-239
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• 2007

본 연구의 주요 목적은 시멘트 복합 재료의 소성 수축 균열 제어에 폐 PET병으로부터 만들어진 재생 PET 섬유의 효과를 평가하는 것이다. PET은 플라스틱 재료라 알려진 재료로 음료수 병 등에 다양하게 적용되어 왔다. 그렇지만 폐 PET 병은 사용 후에 환경적 측면에서 큰 문제점으로 부각되고 있다. 따라서 폐 PET 병을 재활용하는 방법에 대한 연구는 환경 및 경제적 측면에서 중요하게 되었다. 폐 PET 병을 재활용하는 방법 중 시멘트 복합 재료의 보강 섬유로 사용하는 방법은 효과적인 방법 중에 하나이다. 본 연구에서는 시멘트 복합 재료의 소성 수축 균열에 재생 PET 섬유의 형상 및 길이의 효과를 얇은 슬래브 실험을 통해서 조사하였다. 실험 계획은 섬유의 형상, 길이 및 혼입률의 영향을 이해하기 위하여 수행하였다. 재생 PET섬유의 형상은 straight, crimped및 embossed type의 3가지 형상을 포함하며, 각 3가지 섬유형상 마다 3가지 수준의 섬유 혼입률 및 2가지 종류의 섬유 길이에 대해서 조사하였다. 실험 결과 재생 PET섬유는 시멘트 복합 재료의 소성 수축 균열에 효과적이었다. 섬유의 길이의 관점에서 길이가 긴 섬유는 섬유의 형상이 동일할 때 섬유체적비가 적을 때 효과적이며, 섬유체적비가 증가하면 길이가 짧은 섬유가 더욱더 효과적이었다. 또한 embossed type의 섬유는 적은 섬유 혼입률에서 다른 형상의 섬유보다 소성 수축 균열 제어 효과가 우수하였으며, 높은 섬유 혼입률에서는 straight type의 섬유가 다른 형상의 섬유보다 시멘트 복합 재료의 소성 수축 균열 제어에 가장 효과적이었다.

• 한국기계가공학회지
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• 제17권4호
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• pp.137-142
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• 2018

Recycled synthetic resin materials produced from waste vinyl and waste plastic contain many foreign substances. Plastic products made from this recycled resin materials containing foreign substances are of poor quality, with reduced the strength and rigidity. Foreign substances include heavy metals, cement, foil, dyed paper and dust. In this study, the scratch-Dies process; which remove foreign sbustances, with precision and automation, through a three-stage mesh filter, is designed. The process is evaluated with finite element analysis according to vibration loading and make. After installing the manufactured equipment, recycled resin was producde, and its heavy metal content was evaluated. Recycled synthetic resin materials were also used plastic products and evaluate their strength. In addition, the change in production was assessed.

• Journal of the Korean Wood Science and Technology
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• 제47권4호
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• pp.472-485
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• 2019

When wood plastic composites (WPCs) have been used for a certain period of time, they become waste materials and should be recycled to reduce their environmental impact. Waste WPCs can be transformed into reinforced composites, in which fillers are used to improve their performance. In this study, recycled WPCs were prepared using different proportions of waste WPCs, nanoclay, and glass fiber. The effects of nanoclay and glass fiber on the microstructural, mechanical, thermal, and water absorption properties of the recycled WPCs were investigated. X-ray diffraction showed that the nanoclay intercalates in the WPCs. Additionally, scanning electron micrographs revealed that the glass fiber is adequately dispersed. According to the analysis of mechanical properties, the simultaneous incorporation of nanoclay and glass fiber improved both tensile and flexural strengths. However, as the amount of fillers increases, their dispersion becomes limited and the tensile and flexural modulus were not further improved. The synergistic effect of nanoclay and glass fiber in recycled WPCs enhanced the thermal stability and crystallinity ($X_c$). Also, the presence of nanoclay improved the water absorption properties. The results suggested that recycled WPCs reinforced with nanoclay and glass fiber improved the deteriorated performance, showing the potential of recycled waste WPCs.