• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.10a
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• pp.167-170
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• 2010

This study is aiming at analyzing correlation between flashover's time and maximum smoke production rate's time on sandwich panel specimens. For this analysis, KS F ISO 137481-1 has been performed for 23 kinds of sandwich panels which mainly consist of EPS, PIR, PUR, Glass wool and so on. KS F ISO 13784-1 represents real scale reaction-to-fire test and focuses on measuring flashover phenomenon rather than other tests as like ISO 5660-1 and SBI.

• Resources Recycling
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• v.6 no.2
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• pp.12-21
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• 1997

Plastics waste constitutes approximately 23% by volume of the municipal solid waste(MSW) generated in the U.S. each year, and have slow rate of degradation in the environment. Therefore, there is a great deal of public pressure to recycle plastics, and more than 100 million people participate in the curbside recycling programs. Despite the high level of public interest, only 3.5% of the plastic are recycled, which is substantially lower than the recycle rates of other materials such as paper fibers, glass, and iron. Although a large part of the reason is due to the low price of virgin polymers, which in turn is due to the low price of oil, it is possible to make the plastics recycling as a profitable business by developing advanced technologies. In this communication, various methods of separating pplastics from metals and from each other are discussed.

• Steel and Composite Structures
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• v.45 no.1
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• pp.147-157
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• 2022

This study assessed the compressive and tensile strengths and modulus of elasticity of waste polyethylene terephthalate (PET) using the ASTM standard tests. In addition, short carbon and glass fibers were mixed with waste PET to examine the improvements in ductility and strength during compression. The bonding was examined via field-emission scanning electron microscopy. The strength degradation of the waste PET tested under UV was 40-50%. However, it had a compressive strength of 32.37 MPa (equivalent to that of concrete), tensile strength of 31.83 MPa (approximately ten times that of concrete), and a unit weight of 12-13 kN/m3 (approximately half that of concrete). A finite element analysis showed that, compared with concrete, a waste PET pile foundation can support approximately 1.3 times greater loads. Mixing reinforcing fibers with waste PET further mitigated this, thereby extending ductility. Waste PET holds excellent potential for use in foundation piles, especially while mitigating brittleness using short reinforcing fibers and avoiding UV degradation.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.2
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• pp.65-71
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• 2018

Paper packs, glass bottles, metal cans, and plastic materials are classified according to packaging material recycling groups that are Extended Producer Responsibility (EPR). In the case of waste paper pack, the compressed cartons are dissociated to separate polyethylene films and other foreign substance, and then these are washed, pulverized and dried to produce toilet paper. Glass bottle for recycling is provided to the bottle manufacturers after the process of collecting the waste glass bottle, removing the foreign substance, sorting by color, crushing, raw materializing process. Waste glass recycling technology of Korea is largely manual, except for removal of metal components and low specific gravity materials. Metal can is classified into iron and aluminum cans through an automatic sorting machine, compressed, and reproduced as iron and aluminum through a blast furnace. In the case of composite plastic material, the selected compressed product is crushed and then recycled through melt molding and refined products are produced through solid fuel manufacturing steps through emulsification and compression molding through pyrolysis. In the recycling process of paper packs, glass bottles, metal cans, and plastic materials, the influx of recycled materials and other substances interferes with the recycling process and increases the recycling cost and time. Therefore, the government needs to improve the legal system which is necessary to use materials and structure that are easy to recycle from the design stage of products or packaging materials.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.521-528
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• 2021

The high-density fiber composite manufacturing method by the extrusion molding method has the characteristic that continuous production is possible, and the product is molded through a mold forming a specific cross-section. OPC is used as a defect material, an appropriate amount of SiO₂ is supplied for CaO reaction activity, and high density and high strength are expressed through steam and autoclave curing. However, due to the use of organic reinforcing fibers, the flame duration exceeds the regulations during the non-combustible performance test, making it difficult to secure performance. In this study, the product was produced by mixing alkali-resistant organic fiber and fly ash having voids as a binder by replacing the existing polypropylene fiber. appeared to be possible.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.3
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• pp.234-243
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• 2023

The electromagnetic pulse(EMP) is a general term for high-output electromagnetic waves, and is classified into EMP generated from nuclear weapons, non-nuclear EMP, and EMP generated by natural phenomena. Electromagnetic pulses are means that can cause fatal damage to all electronic devices with electromagnetic elements, such as communication devices, mobile phones, computers, TVs, and means of transportation. In this study, the electromagnetic pulse(EMP) shielding effectiveness evaluation of paints according to the type and amount of carbon material was conducted to develop EMP shielding inorganic paint using carbon materials. In order to analyze the improvement of compatibility and dispersibility between materials, experiments were conducted two times with about 27 types of mixture proportions, and the electromagnetic pulse shielding effectiveness was evaluated by the electrical resistance measurement method. As a result of applying the EMP shielding paint developed through this study to shielding concrete, it was confirmed that the shielding performance was improved from about 25 dB to a maximum of 40 dB.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.3
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• pp.177-183
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• 2023

Various failure modes occur in the concrete beams reinforced with GFRP(Glass Fiber Reinforced Plastic) under initial condition and repairing patterns. In this study, the failure behaviors of concrete beams restrengthened with GFRP sheet with slightly higher elastic modulus than concrete were investigated. For the tests, concrete beams with 24 MPa were manufactured, and the effects of initial notch, overlapping, end-strip reinforcement, and fiber anchors were analyzed on failure load. The cases of GFRP overlap around notch and the initial notch showed increasing failure loads similar to those of normal restrengthened case since the epoxy of the saturated GFRP sufficiently repaired the notch area. Compared to the control case without restrengthening of GFRP, the concrete with initial notch showed 0.78 of loading ratio and normal restrengthening showed 4.43~5.61 times of increasing ratio of failure loading, where interface-debonding from flexural crack were mainly observed. The most ideal failure behavior, break of GFRP, was observed when end-strip over 1/3 height from bottom and fiber anchor were installed, which showed increasing failure load over 150 % to normal restrengthening.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.4
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• pp.199-204
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• 2003

Microstructure and chemical analysis of sintered bricks containing recycled wastes were investigated by SEM and EDS. The recycled wastes for which substitute ceramic raw materials were EAF (electric arc furnace) dust, fly ash and stone ash. Yellowish and brownish regions on the surface and brownish and blackish regions in the inside of bricks were observed. Main component of yellowish region on the surface turned out to be Zn. No chemical difference between the black-core region and brownish matrix. Mullite crystallites of 1 fm size were distributed in the inside of bricks and enclosed by glass phases. It seems that alumine-silicate mixtures of kaolin and fly ash were transformed to mullite crystallites during the sintering. Relatively large pores ot several ten fm size were observed in the black-core region in the inside of bricks. The main components of the inside of brick were Al and Si. The minor components were C, Na, Mg, K, Ca, and Fe. Particularly, the precipitates of Fe-rich crystallites were observed in the amorphous matrix. These precipitates were formed due to the local reduction atmosphere in the inside of bricks. Zn-rich covers were found on the surface of bricks because Zn diffused from the inside of bricks to the surface under the reduction atmosphere.

• Journal of the Korea Concrete Institute
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• v.13 no.2
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• pp.184-191
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• 2001

Recently, as industrialization is rapidly growing and the standard of life is rising, the quantities of waste glasses have been hastily increased and most of them are not recycled but abandoned. It cause some problems such as the waste of natural resources and environmental pollution. Therefore, this study was conducted basic experimental research to analyze the possibilities of recycling of waste glasses(crushed waste glasses outbreaking from our country such as amber, emerald-green, flint and mixed) as fine aggregates for concrete. Test results of fresh concrete, slump and compacting factors decrease because grain shape is angular and air content increase due to involving small size particles so much in waste glasses. Also compressive, tensile and flexural strengths decrease with increase of the content of waste glasses. In conclusion, the content of waste glasses below 30% is reasonable and usage of pertinent admixture is necessary to obtain workability and air content.

• Resources Recycling
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• v.22 no.3
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• pp.50-56
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• 2013

Recycled plastic composites of ABS/PE (50/50 and 20/80) and ABS/GF (90/10) were fabricated from plastic components of waste LCDs and effects of PE composition on elongation of ABS/PE composites were investigated. Increased PE contents improved elongation of the composite from 2.4% to 13%, which was attributed to increased crystalline behavior of the ABS/PE composite afforded by ductile PE fraction: SEM fractographs showed some sign of plastic deformation of PE matrix before ductile fracture of the composites.