• Advances in concrete construction
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• v.12 no.6
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• pp.461-467
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• 2021

Polyethylene-terephthalate (PET) from bottle waste and linear low-density polyethylene (LLDPE) from barrels and tanks waste are widely available and need to be recycled. Recycling them in concrete and mortar is an alternative solution for their disposal. In this study various quantities of sand (5%, 10%, 15% and 20%) were substituted by powder from LLDPE waste. In addition, PET waste fibers (corrugated, straight) were added to the mortar with different percentages (0.5%, 1%, 1.5% and 2%) of cement mass. This paper evaluate the mechanical and physical properties of the composites in fresh (workability, air content and density) and hardened state (compressive and flexural strength, water absorption and total shrinkage). From the experimental results, it can be concluded that the strengthening in tensile of the mortar with plastic waste corrugated fibers is improved. Other important results are that the water absorption and the density rate are less than that of the ordinary mortar.

• Journal of the Korea Fashion and Costume Design Association
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• v.23 no.4
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• pp.133-148
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• 2021

Due to the COVID-19 pandemic, many people started working from home while avoiding unnecessary going-outs. As the 'stay-at-home life' becomes standard daily life, the pajamas market is absorbing young consumers, especially targeting Generation MZ, by using one-mile fashion that breaks down the boundary with everyday clothes. Also, owing to the demand for environmentally-friendly textiles, based on the strengthened environmental regulations, the development of textiles considering the environment is expanding. Thus, the purpose of this study is to develop fashion pajamas using environmentally-friendly textiles targeting Generation MZ. After theoretically considering the current status of recycled PETs and the pajama market by referring to preceding research, relevant books, and Internet data, this study performed the process setting up the design concepts, developing textiles, developing textile designs, and developing pajamas designs. As a result, this study wove two kinds of mixed textiles using recycled PETs and silk with the concept of 'Going out pajamas', and designed a total four patterns to be applied to those textiles, then digitally printed them. Using the developed textiles, this study produced a total four kinds of pajamas that were practical, trendy, and also good to be used as clothes for going-out. The consumers who are exhausted from the limited environment of the COVID-19 pandemic, are requesting comfortable and trendy in & out door fashion. For this reason, the results of this study are significant in the aspect of suggesting the new-normal fashion trend for pajamas designs.

• Resources Recycling
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• v.12 no.5
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• pp.16-22
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• 2003

Lightweight aggregate for concrete was manufactured from recycling the waste PET bottles (PET Bottle Lightweight Aggregate, LAPET). The qualities of LAPET and its mortar were investigated. Specific gravity and unit weight of LAPET was very low in comparison with river sand like as 1.39, 844 kg/㎥ respectively. In addition, compressive strength of concrete significantly decreased because of specific gravity of aggregate decreased with increases in containing ratio. When LAPET was contained to 25% and 50％ of river sand, compressive strength of concrete at 28 days was indicated more 30MPa. Most of LAPET was generally showed to round shape and fluidity of mortar increased significantly due to sleeking the surface texture of LAPET. On the other hand, capillary absorption of mortar with LAPET was greatly increased in comparison with that of mortar without LAPET because of LAPET was composed of singular gradation. Absorption of LAPET was 0％ because the interior structure of LAPET consists of PET like as organic high polymer. Therefore the fault of normal lightweight aggregate, absorption, will be improved. It could expect several advantages that the pollution of environment will be previously prevent and the waste resources could be recycled if LAPET is reused as aggregate for Lightweight concrete.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.543-550
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• 2009

This study was performed to prove the possibility of utilizing short plastic fibers made for recycled polyethylene terephthalate (RPET) as a structural material. In order to verify the capacity of RPET fiber, it was compared with polypropylene (PP) fiber, most widely used short synthetic fiber, for fiber volume fraction of 0%, 0.5%, 0.75%, and 1.0%. To measure material properties such as compressive strength, split tensile strength, appropriate tests were performed. Also, to measure the strength and ductility capacities of reinforced concrete (RC) member casted with RPET fiber added concrete, flexural test was performed on RC beams. The results showed that compressive strength decreased, as fiber volume fraction increased. These trends are similarly observed in the tests of PP fiber added concrete specimens. Split cylinder tensile strength of RPET fiber reinforced concrete increased slightly as fiber volume fraction increased. For structural member performance, ultimate strength, relative ductility and energy absorption of RPET added RC beam are significantly larger than OPC specimen. Also, the results showed that ultimate flexural strength and ductility both increased, as fiber volume fraction increased. These trends are similarly observed in the tests of PP fiber added concrete specimens. The study results indicate that RPET fiber can be used as an effective additional reinforcing material in concrete members.

• Journal of the Korean Society of Safety
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• v.27 no.5
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• pp.117-125
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• 2012

In recent years, polymer concrete based on polyester resin have been widely generalized and the research of polymer concrete have been actively pursued by the technical innovations. Polymer concrete is a composite consisting of aggregates and an organic resin binder that hardens by polymerization. Polymer concrete are stronger by a factor of three or more in compression, a factor of four to six in tension and flexural and a factor of two in impact when compared with portland cement concrete. In view of the growing use of polymer concrete, it is important to study the physical characteristics of the material, emphasizing the short term properties as well as long term mechanical behavior. If polymer concrete is to be used in flexural load-bearing application such as in beam, it is imperative to understand the deformation of the material under sustained loading conditions. This study is proposed to empirical and mechanical model of polymer concrete tension creep using long-term experimental results and mathematical development. The test results showed that proposed model has been used successfully to predict creep deformations at a stress level that was 20 percent of the ultimate strength and viscoelastic behavior of recycled-PET polymer concrete is linear of stress level up to 30 percent. It is expected that the present model allows more realistic evaluation of varying stresses in polymer concrete structures with a constant loading.

• Journal of Adhesion and Interface
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• v.24 no.1
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• pp.17-25
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• 2023

In this study, waste polyethylene terephthalate (PET) was recycled to produce a support and then polyetherimide (PEI) was used for environmentally friendly organic solvent nanofiltration. The prepared composite membrane was first prepared by electrospinning a PET support, then casted on the support using PEI having excellent solvent resistance, and organic solvent nanoparticles using a Non-solvent Induced Phase Separation (NIPS) method. A filtration membrane was prepared. First, the fiber diameter and tensile strength of the PET scaffold prepared prior to membrane fabrication were identified through morphology analysis, and the optimal scaffold for the organic solvent nanofiltration membrane was identified. Afterward, the PET/PEI composite membrane prepared was checked for the DEA removal rate of Congo red having a molecular weight of 697 g/mol in ethanol to understand the performance as an organic solvent nanofiltration membrane according to the concentration of PEI. Finally, the removal rate of Congo red was 90% or more.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.545-546
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• 2009

This study was performed to prove the possibility of utilizing short plastic fibers made for recycled polyethylene terephthalate (RPET) as a structural material. To measure of crack control capacity, restrained drying shrinkage cracking test was performed. In order to verify the capacity of RPET fiber, it was compared with poly propylene (PP) fiber, most widely used short synthetic fiber, for fiber volume fraction of 0%, 0.5%, 0.75%, and 1.0%.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.840-845
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• 2003

Polymer concrete (PC) using unsaturated polyester resins based on recycled polyethylene terephthalate (PET) plastic waste were used in our study for grasping its mechanical properties such as compressive strength, tensile strength and flexural strength, etc. by changing its quantity of resin, filler and dilution(SM) respectively. As a result of it, compressive, tensile and flexural strength of PC indicated 752kgf/$cm^2$, 80kgf/$cm^2$, and 243kgf/$cm^2$, kind of satisfaction successively. Judging from the above results, polymer concrete (PC) using unsaturated polyester resins as a coupling are suitable for construction material both in the aspect of ECO-building materials and in the aspect of superior strength of PC so that it is good possibility of success as a product.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.3
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• pp.152-159
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• 2010

Recently, the public interest in eco-friendly material and structure has been increasing and many Hwang-toh researches are being actively performed. Hwang-toh is one of the traditional environment friendly construction materials used as a construction and plastering material. Hwang-toh has many advantages as construction material due to its high heat storage capacity, auto-purification, antibiotic ability, and infrared ray emission characteristics. But, currently it has not been developed into construction material and used in modern construction due to its low strength and dry shrinkage cracking prone characteristics. According to the recent researches and study results, Hwang-toh can be used as a natural pozzolanic material like fly-ash or pozzolan. In this study, mechanical properties and structural flexure behavior experiments of slag, recycled PET fiber, and Hwang-toh added concrete are carried out. The test results showed that drying shrinkage of concrete mixed with Hwang-toh has lower compressive strength and elastic modulus than those of control cement concrete specimen, but it has the similar flexural behavior in reinforced concrete beams.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.72-72
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• 2012

본 연구에서는 친환경 리싸이클 섬유산업의 활성화를 위해 대학생들의 리싸이클 폴리에스터 섬유에 대한 인식도를 분석해 보고자 하였다. 측정 문항은 섬유전문가 3인의 검토를 거쳐 타당성을 확보하였으며, 조사는 질문지법으로 2011년 9월 1일부터 9월 10일까지 대전 거주 대학생을 대상으로 진행하였으며, 회수된 설문지 196부를 자료 분석에 이용하였고, SPSS 19 통계 패키지를 이용하여 자료를 통계분석하였다. 연구 결과는 다음과 같다. 1. 친환경적 의생활 실태 조사를 실시한 결과, 리싸이클 PET섬유에 대해 들어본 적이 있는 사람은 조사대상자의 27.6%로 나타났고, 그 정보원으로는 인터넷을 가장 많이 이용하는 것으로 나타났다. 2. 섬유소재별 친환경성에 대한 인식도를 조사한 결과, 대학생들은 리싸이클 PET섬유가 천연섬유보다 덜 친환경적이나, 인조섬유보다는 더 친환경적이라고 인식하는 것으로 나타났다. 3. 리싸이클 PET섬유에 대한 인식도를 요인분석한 결과, <친환경성 요인>, <촉감 요인>, <내구성 요인>, <기능성 요인>, <공정 요인>, <글로벌 경쟁력 요인>및 <부가가치성 요인> 등 7개의 요인이 도출되었는데 이는 대학생들은 리싸이클 PET섬유에 대해 친환경성, 촉감, 내구성, 기능성, 공정, 글로벌경쟁력, 부가가치성순으로 중요하게 인식하는 것으로 해석된다.