• Resources Recycling
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• 제12권5호
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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.

• Advances in concrete construction
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• 제16권6호
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• pp.291-302
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• 2023

As the first part of the body that strikes the ground during running, sports shoes are especially important for improving performance and reducing injuries. The use of new nanotechnology materials in the shoe's sole that can affect the movement angle of the foot and the ground reaction forces during running has not been reported yet. It is important to consider the material of the sole of the shoe since it determines the long-term performance of sports shoes, including their comfort while walking, running, and jumping. Running performance can be improved by polymer foam that provides good support with low energy dissipation (low energy dissipation). Running shoes have a midsole made of ethylene propylene copolymer (EPP) foam. The mechanical properties of EPP foam are, however, low. To improve the mechanical performance of EPP, conventional mineral fillers are commonly used, but these fillers sacrifice energy return. In this study, to improve the magnificence of physical education training with nanotechnology, carbon nanotubes (CNTs) derived from recycled plastics were prepared by catalytic chemical vapor deposition and used as nucleating and reinforcing agents. As a result of the results, the physical, mechanical, and dynamic response properties of EPP foam combined with CNT and zinc oxide nanoparticles were significantly improved. When CNT was added to the nanocomposites with a weight percentage of less than 0.5 wt%, the wear resistance, physical properties, dynamic stiffness, compressive strength, and rebound properties of EPP foams were significantly improved.

• Journal of the Korean Recycled Construction Resources Institute
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• 제1권1호
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• pp.17-25
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• 2013

Thermal storage technology used for indoor heating and cooling to maintain a constant temperature for a long period of time has an advantage of raising energy use efficiency. This, the phase changing material, which utilizes heat storage properties of the substances, capsulizes substances that melt at a constant temperature. This is applied to construction materials to block or save energy due to heat storage and heat protection during the process in which substances melt or freeze according to the indoor or outdoor temperature. The micro-encapsulation method is used to create thermal storage from phase changing material. This method can be broadly classified in 3 ways: chemical method, physical and chemical method and physical and mechanical method. In the physical and chemical method, a wet process using the micro-encapsulation process utilized. This process emulsifies the core material in a solvent then coats the monomer polymer on the wall of the emulsion to harden it. In this process, a surfactant is utilized to enhance the performance of the emulsion of the core material and the coating of the wall monomer. The performance of the micro-encapsulation, especially the coating thickness of the wall material and the uniformity of the coating, is largely dependent on the characteristics of the surfactant. This research compares the performance of the micro-capsules and heat storage for product according to molecular mass and concentration of the surfactant, SSMA (sulfonated styrene-maleic anhydride), when it comes to micro-encapsulation through interfacial polymerization, in which Dodecan-1 is transformed to melamin resin, a heat storage material using phase changing properties. In addition, the thickness of the micro-encapsulation wall material and residual melamine were reduced by adjusting the concentration of melamin resin microcapsules.