• International conference on construction engineering and project management
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• 2007.03a
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• pp.625-634
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• 2007

Energy-saving is one of important issues in multi-family housing projects in South Korea. According to the study by Yu et al. (2002), the balcony conversion causes energy loss approximately one and a half times. Therefore, it is important to select the economical glass type in the balcony window. In order to identify the most economical glass type of balcony conversion in multi-family housing projects, the most typical type of the multifamily housing projects in the metropolitan area was selected as a candidate project. The selected candidate project has been simulated using ENERGY-10 program to estimate the heat load by the different five types of glasses as well as their life cycle cost analysis (LCCA) using present worth method. Finally, sensitivity analysis has been conducted to determine the most economical glass types under a different discount rate (interest rate) and service life of building.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.136-137
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• 2021

The soda lime waste glass powder was dissolved in NaOH-4M solution to synthesize an alkaline activator, which was used to activate Class-C fly ash (FA). Compressive and flexural strength tests were conducted to determine the mechanical properties. Archimedes' principle was applied to measure the porosity of samples, (SEM-EDX) and XRD was used to study the microstructure and phase changes of samples. Through Inductive Coupled Plazma technique, the solution was found to increase the concentration of Si as the amount of dissolved glass powder was increased. Owing to the increased concentration of Si in an alkaline solution, the reactivity of FA was accelerated resulting in an increased strength and reduced porosity. Additionally, the dissolution of FA was improved as well as the formation of amorphous phases in the matrix was also enhances with the concentration of increased Si in an alkaline solution.

• Earthquakes and Structures
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• v.8 no.1
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• pp.101-132
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• 2015

This research formulates a closed-form equation to predict a glass panel cracking failure drift for several curtain wall and storefront systems. An evaluation of the ASCE 7-10 equation for Dclear, which is the drift corresponding to glass-to-frame contact, shows that the kinematic modeling assumed for formulation of the equation is sound. The equation proposed in this paper builds on the ASCE equation and offers a revision of that equation to predict drift corresponding to cracking failure by considering glazing characteristics such as glass type, glass panel configuration, and system type. The formulation of the proposed equation and corresponding analyses with the ASCE equation is based on compiled experimental data of twenty-two different glass systems configurations tested over the past decade. A final comparative analysis between the ASCE equation and the proposed equation shows that the latter can predict the drift corresponding to glass cracking failure more accurately.

• Journal of Korean Society on Water Environment
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• v.28 no.2
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• pp.219-223
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• 2012

The fixed solid catalysts such as glass bead, steel mesh, and $TiO_2$ coated ceramic bead were used to investigate effect of radical production at different frequencies. The radical production rate at 300 kHz was faster than that at 35 kHz without solid, but the tendency was changed with the presence of glass bead. The presence of glass beads create non-continuous points between the solid and liquid phases leading to increased formation of cavitation bubbles. However, the radical production decreased when steel mesh was used at 35 kHz although the surface area of contact with liquid was same when glass bead was used. Hence the solid catalyst did not always enhance the radical production. The radical production using $TiO_2$ coated ceramic bead was dramatically increased at 35 kHz due to the breakage of $TiO_2$ coated ceramic bead. Therefore the radical productions at 300 kHz using fixed solid catalysts generally increased while at 35 kHz the results fluctuated according to the experimental conditions.

• Computers and Concrete
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• v.17 no.2
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• pp.255-269
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• 2016

The waste glass sludge is a waste produced in the glass industry. It is in a dust form and disposed with water. In the disposal process, various cohesive agents are incorporated in order to precipitate the glass particles efficiently. In this paper, we investigate the pozzolanic reaction of the waste glass sludge incorporating precipitation additives experimentally. The consumption of calcium hydroxide, the setting time and the compressive strength and the pore structure were tested for two different types of the waste glass sludge depending on whether precipitation additives were used. It was found that the waste glass sludge incorporating the precipitation additives had a higher pozzolanic potential than the reference waste glass sludge without precipitation additives.

• Journal of the Korean Solar Energy Society
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• v.27 no.1
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• pp.83-90
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• 2007

Apartment balcony has been indiscreetly remodeled since the government permitted remodeling on January 2006. But remodeled balcony has a few problems such as increase of heating energy, surface condensation and cold draft. The reason of thermal problem is mainly caused by the window system in a extended balcony. The purpose of this study is to analyze heating and cooling energy and propose the efficient window types for the extended balcony area of a apartment building. 4 types of window system which have fairly high U value in Korea are investigated as follows ; double clear glass, double low-e glass, triple clear glass and triple low-e glass. Comparing double clear 91ass with double low-e glass, triple clear glass and triple low-e glass, simulation results show that 10%, 7% and 15% saving of total primary energy can be expected.

• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.21-22
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• 2021

This study incorporates fine waste glass (GS) as a replacement for natural sand (NS) in ground granulated blast furnace slag (GGBS) based alkali activated mortar (AAm). Tests were conducted on the AAm to determine the mechanical properties, apparent porosity and the durability based on its resistance to Na2SO4 5% and H2SO4 2% concentrated solutions. The study revealed that increasing GS up to 100 wt%, increased strength and decreased porosity. The lower porosity attained with the incorporation of GS, improved the resistance of mortar to Na2SO4 and thus increasing durability. However, the durability of mortar to H2SO4 solution was negatively impacted with the further reduction of porosity observed with increasing GS above 50 wt.% believed to be caused by the stress induced as a result of expansive reaction products created when the mortar reacted with acid.

• 한국태양에너지학회:학술대회논문집
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• 2008.11a
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• pp.90-95
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• 2008

An SHGC(Solar Heat Gain Coefficient) is a determinant of total flux of solar radiation coming indoor and a critical factor in evaluating heating and cooling load. U-value represents heat loss while SHGC denominates heat gain. Recently, windows with high solar gain, mid solar gain or low solar gain are being produced with the development of Low-E coating technology. This study evaluated changes in energy consumption for heating and cooling according to changes in SHGC when using double-layered Low-E glass and triple layered Low-E glass in relation to double layered clear glass as base glass. An Office was chosen for the evaluation. For deriving optical properties of each window, WINDOW 5 by LBNL, an U.S. based company. and the results were analyzed to evaluate performance of heat and cooling energy on anannual basis using ESP-r, an energy interpretation program. Compared to the energy consumption of the double layered clear glass, the double layered Low-E glass with high solar gain consumed $69.5kWh/m^2,yr$, 9% more than the double layered clear glass in cooling energy. The one with mid solar gain consumed $63.1kWh/m^2,yr$, 1% less than the base glass while the one with low solar gain consumed $57.6kWh/m^2,yr$, 10% less than the base glass. When it comes to tripled layered glass, the ones with high solar showed 2% of increase respectively while the one with mid solar gain and low solar gain resulted 5% and 11% in decrease in energy consumption due to low acquisition of solar radiation. With respect to cooling energy. it was found that the lower the SHGC. the less energy consumption becomes.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.1
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• pp.74-79
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• 2022

In this study, the effect of a sudden decrease in internal humidity and a decrease in hydration level due to the tight internal structure of high-strength concrete and cement composites was investigated. To verify the change in the internal Si hydration, waste glass foam beads were used as a lightweight aggregate, and the internal unreacted hydrate reduction and hydrate formation tendency were identified over the mid- to long-term. Waste glass foam beads were mixed with 5, 10, and 20 %, and were used by pre-wetting. As the mixing rate of the waste glass foamed beads increased, the strength showed a tendency to decrease. In addition, when the mixing amount of pre-wetted waste glass foam beads increases inside through XRD analysis, TGA analysis, and Si NMR analysis, it is judged that the hydration degree of internal Si is different because moisture is supplied to the paste.