• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.2
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• pp.143-150
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• 2010

Vitrification technology has been gradually recognized as one of effective solidification methods for concentrated boric acid wastes generated in PWR. Vitrification for low- and intermediate-level radioactive wastes has a large volume reduction and good durability for the final products. A feasibility study for the vitrification of concentrated boric acid wastes has been performed with developing the pre-treatment methods of powdered wastes, glass compositions using glass formulation and demonstration test. The pre-treatment method is pelletizing the powder type for stable feeding within cold crucible melter. The glass compositions should be developed considering molten glass are related with wastes reduction. High contents of sodium and boron within borate wastes give influence to waste loading. A variety of factors obtained from the demonstration test are reviewed, which is wastes feeding rate, off-gas characteristics on stack and glass characteristics of final products such as durability for implementing the wastes disposal requirement. The aim of this paper is to present the feasibility of vitrification and review the solidification method for concentrated boric acid wastes and obtain the physicochemical characteristics of solidified glass.

• Resources Recycling
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• v.17 no.1
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• pp.29-37
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• 2008

Recently, domestically and internationally, the occurrences of Waste Glass are on the increase. Most of scrap glass are either reused of recycled. However, glass not recycled is buriedand is causing secondary environmental problem. With 5% mixture of Waste Glass, the average paste viscosity (rheology) decreased by 22.3% and 28-day compressive strength of mortar's flow and aging decreased by 1.5% and 6% respectively. Also, as Waste Glass mixture ratio of un-hardened elf-compacting concrete increased, fluidity increased and compressive strength decreased. In consideration of adequate compressive strength and fluidity that meets the 2nd class JSCE regulations; optimum mixture ratio of Waste Glass can be concluded as 20%.

• Applied Chemistry for Engineering
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• v.28 no.5
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• pp.513-520
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• 2017

The application possibility of an alternative new method with low energy consumption was studied for the eco-friendly fabrication of foamed glasses from waste glasses. As a result, fabricating temperature can be reduced under $300^{\circ}C$ without using various expensive inorganic oxidants. The foamed glass can be fabricated at a proper mixing ratio of the waste glass powder, water glass, little surfactant and bubble stabilizer by induction heating method. In the experimental range, the assured optimal condition is 4 min heating on the induction machine with a steel-container ($100mm{\times}100mm{\times}20mm$) and followed by evaporating and drying process for 11 min with 110 g of glass powder, 80 g of water glass, 3 g of surfactant and 0.2 g of bubble stabilizer. When the foamed glass was fabricated at the optimal condition, the density of the glass was $0.85g/cm^3$ and the heat conduction was $0.052W/h{\cdot}K$. In addition, the compressive strength of the glass was above $50kg/cm^2$.

• Journal of the Korea Institute of Building Construction
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• v.9 no.3
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• pp.109-116
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• 2009

The magnesium sulfate solution digestion test carried out for resistance of concrete containing waste glass powder on magnesium sulfate attack. Moreover, it yielded S.D.F index was used for the criteria of quantitative assessment to the resistance of magnesium sulfate for the purpose of evaluation of chemical deterioration on concrete. Furthermore, to evaluate for micro-cracks within concrete and external corrosion, the weight variation of specimens and the dynamic elasticity were compared and analyzed and also the applicability was examined using the analysis of product of hydration through out observing external deformation and micro-structural deformation.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.4
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• pp.335-340
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• 2005

The forward dissolution rate of a borosilicate waste glass was determined as an interlaboratory study(ILS) testing program for the evaluation of precision in the measurement of the dissolution rate or a waste glass using a single-pass flow-through(SPFT) test, whose conducting practice has been written for standardization through American Society for Testing and Materials (ASTM). A simulated low-activity waste glass powder with a size of 100/200 mesh was dissolved by lithium buffer solution (pH=10) at 70? under Ar atmosphere. By plotting the dissolution rates as a function of silicon and boron concentration in eluate, the forward dissolution rate of the glass was obtained as about $2.7\times10^{-5}g{\cdot}m{\cdot}s^{-1}$ in our laboratory.

• Magazine of RCR
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• v.13 no.1
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• pp.14-20
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• 2018

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.77-78
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• 2020

An alkaline activator was synthesized by dissolving waste glass powder (WGP) in NaOH-4M solution to explore its effects on the Class-C fly ash (FA) and ground granulated blast furnace slag (GGBS) based alkali-activated material (AAM). The compressive strength and porosity were measured, and (SEM-EDX) were used to study the hydration mechanism and microstructure. Results indicated that the composition of alkali solutions was significant in enhancing the properties of the obtained AAM. As the amount of dissolved WGP increased in alkaline solution, the silicon concentration increased, causing the accelerated reactivity of FA/GGBS to develop Ca-based hydrate gel as the main reaction product in the system, thereby increasing the strength. Further increase in WGP dissolution led to strength loss, which were believed to be due to the excessive water demand of FA/GGBS composites to achieve optimum mixing consistency. Increasing the GGBS proportion in a composite also appeared to improve the strength which contributed to develop C-S-H-type hydration.

• Structural Engineering and Mechanics
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• v.74 no.5
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• pp.671-678
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• 2020

In this work, the dynamic properties of a high performance concrete containing glass powder (GP) was studied. The GP is a new cementitious material obtained by recycling waste glass presenting pozzolanic activity. This eco-friendly material was incorporated in concrete mixes by replacing 20 and 30% of cement. The mechanical properties of building materials highly affect the response of the structure under dynamic actions. First, the resonant vibration frequencies were measured on concrete plate with free boundary conditions after 14, 28 and 90 curing days by using an alternative vibration monitoring technique. This technique measures the average frequencies of several excitations done at different points of the plate. This approach takes into account the heterogeneity of a material like concrete. So, the results should be more precise and reliable. For measuring the bending and torsion resonant frequencies, as well as the damping ratio. The dynamic properties of material such as dynamic elastic modulus and dynamic shear modulus were determined by modelling the plate on the finite element software ANSYS. Also, the instantaneous aroused frequency method and ultrasound method were used to determine the dynamic elastic modulus for comparison purpose, with the results obtained from vibration monitoring technique.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.1
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• pp.23-28
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• 2009

There is several ways of recycling methods for waste FRP boats. The main one is mechanical recycling that is one of the simple and technically proven methods. It recently has been reported that FRP can be recycled by separating into laminated glass fiber layers instead of crushing into powder. Even though the mechanical recycling is a good way for the eligibility of laminated glass fiber reinforced material, the system should have another option which can collect resin of FRP. Because the resin is still very useful renewable energy source, that cannot be discarded, But FRP is made up of laminated glass fiber(roving cloth layer) which is fire retardant substances and very hard to break into each layer. Due to the high cost of fossil energy the waste plastics should be regenerated to the source of renewable energy. Laminated glass fiber which is recyclable in a very limited way, is currently a serious barrier to waste FRP boat regenerating. This study is to propose a new extracting method which is efficient and environment friendly FRP waste regenerating system. The recycled glass fiber which is obtained by the separation of the roving layer from FRP waste has been found to be useful for concrete(FRC) products or concrete(FRC) structures as fiber reinforced material. And it can be successively applied to renewable energy applications using the waste resins of FRP residue without laminated glass fiber.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.32-33
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• 2016

In this work, pozzolanic activities of various waste materials were compared with those of well-known pozzolanic materials. Uncondensed and densified silica fume, two ASTM class F fly ashes with different calcium contents, and bentonite powder, ceramic powder obtained from wash basin, and waste glass wool, which can possibly possess pozzolanic property were chosen for comparison. Drop in electrical conductivity at 40℃ saturated lime solution was measured for each materials. The amount of Ca(OH)₂ decomposed from cement paste at 450~500℃ was also measured used to evaluate pozzolanic activity. The 28 day compressive strength were used to observe the mechanical property enhanced by various waste materials.