• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.55-56
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• 2016

In the recent concrete industry, when producing recycled aggregates, waste concrete powder is by-produced in large quantities; however, since it is not used properly but buried or discarded. This study is to apply the waste concrete powder to a cement extruding panel as filler. Flexural strength and microstructure characteristics of panel is tested in order to improve the economics of the extruding panel. As a results of this study, it was found that extruding panel replacing silica(No.8) as the waste concrete powder totally showed little difference in the strength and satisfied the target flexural strength of 14MPa, comparing with controlled panel. In addition, we can understand that rich Portlandite and Calcite contributed to develop the strength in all curing conditions from XRD pattern.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.493-498
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• 2008

The several water resources are showed recently the various pollution types due to the industrialization and the disarranged district development. The living waste water, plant waste water and so are contaminated continuously and the recycling water is concerned highly to save the cost and to improve the environment as the general people. The dust and the heavy metal in the air and the acid rain are contaminating the river water and the underground water. The clean environment is on the rise to the general people and is to be the social problems. There is going to complement and repair the water supplying and fire extinguishing pipeline to save the construction cost and improve the environment in the construction facilities parts. Therefore, in this paper the recycling water treatment/supply apparatus using the living waste water is considerated technically and is raised on the practical uses.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.424-428
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• 2005

As the application of NPM in waste administration branch this paper proposes a new waste management method in order to increase the efficiency of resources and reduce the quantity of waste. First the matrix method is suggested which comprehensively consider and integrate the proposals of different government departments. Moreover the inhabitant's attitude toward the new waste management measures was investigated. Based on the investigation the evaluation function was made, which include three elements: necessary budget, the effect of cost decrease and the environmental burden decrease. The optimal method of budget allocation to maximize social welfare is proposed under the condition of limited budget by the evaluation function. By applying this system further local governments will be able to determine their adequate service level and budget size.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.112-113
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• 2021

Since natural sand is being depleted, research is being conducted to use glass similar to sand as an aggregate. When non-reusable waste glass is crushed and used as fine aggregate, it is known that alkali of cement and silica of glass react to cause an alkali aggregate reaction. The purpose of this study is to provide basic data by studying the strength according to color to use waste glass as fine aggregate. When 10% was replaced, both flexural and compressive strength showed strength values similar to those of Plain. When replaced by 20% and 30%, the 7-day intensity was higher than that of Plain. In addition, colorless glass was found to have the highest strength among glass colors. More research is expected to be needed to become a fine aggregate of waste glass.

• The Journal of the Korea Contents Association
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• v.19 no.12
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• pp.68-83
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• 2019

The characteristics of intermediate-level waste treatment services are likely to have a negative effect because they act as a factor in promoting incentives of earnings management in the relationship between financial characteristics and earnings management in companies which are possible for earnings management. The researchers conducting this study attempted to empirically verify relationships between financial characteristics and earnings management against domestic construction waste disposal companies in consideration of the characteristics of intermediate-level waste disposal businesses, and the results are as follows. As construction waste disposal businesses grew larger, and the trade receivables collection period lengthened, the intention to increase profits via real activities strengthened. As the ability to generate cash via sales activities weakened, and the difference between the EBITDA margin and the operating margin was lower than the difference in industrial average ratio, discretionary accruals and earnings management via real activities were greater. In particular, there were differences in the variables of intermediate treatment business characteristics which reveal moderating effects by financial characteristics. This study is meaningful in that the scope of relationships between financial characteristics and earnings management in accounting is expanded to cover the construction waste disposal industry.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.4
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• pp.314-320
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• 2014

Although the cement industry serves as the cornerstone of the construction industry by supplying one of its fundamental materials, it confronts new environmental challenges due to the problem of the $CO_2$ generated from raw materials and fuel used in the cement manufacturing process. Also, concrete structures can be decomposed and reused as construction materials. Simply in terms of the cyclic processing of $CO_2$, recycling waste concrete to manufacture recycled aggregate or recycling waste concrete powder, which is the material for cement can be considered optimally environment-friendly practices. This study contributes to the aim of manufacturing high value added materials that exploits the chemical properties of the waste concrete powder. From the research results, waste concrete powder is feasible to use to produce low carbon type recycled cement.

• Advances in concrete construction
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• v.13 no.6
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• pp.433-450
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• 2022

The conventional disposal methods of waste tires are harmful to the environment. Moreover, the recycling/reuse of waste tires in domestic and industrial applications is limited due to parent product's quality control and environmental concerns. Additionally, the recycling industry often prefers powdered rubber particles (<0.60 mm). However, the processing of waste tires yields both powdered and coarser (>0.60 mm) size fractions. Reprocessing of coarser rubber requires higher energy increasing the product cost. Therefore, the waste tire rubber (WTR) less favored by the recycling industry is encouraged for use in construction products as one of the environment-friendly disposal methods. In this study, WTR fiber >0.60 mm size fraction is collected from the industry and sorted into 0.60-1.18, 1.18-2.36-, and 2.36-4.75-mm sizes. The effects of different fiber size fractions are studied by incorporating it as fine aggregates at 10%, 20%, and 30% in the self-compacting rubberized concrete (SCRC). The experimental investigations are carried out by performing fresh and hardened state tests. As the fresh state tests, the slump-flow, T500, V-funnel, and L-box are performed. As the hardened state tests, the scanning electron microscope, compressive strength, flexural strength and split tensile strength tests are conducted. Also, the water absorption, porosity, and ultrasonic pulse velocity tests are performed to measure durability. Furthermore, SCRC's energy absorption capacity is evaluated using the falling weight impact test. The statistical significance of content and size fraction of WTR fiber on SCRC is evaluated using the analysis of variance (ANOVA). As the general conclusion, implementation of various size fraction WTR fiber as fine aggregate showed potential for producing concrete for construction applications. Thus, use of WTR fiber in concrete is suggested for safe, and feasible waste tire disposal.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.2
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• pp.222-228
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• 2024

This study aims to anal yze the social benefits of introducing a sel ective demol ition system for buil dings. Incremental revenue, incremental cost, and incremental profit for the entire nation were derived based on the calculated costs and revenues of selective demolition for a 2,400 m² apartment complex. In conducting selective demolition on a 2,400 m² building, the increase in demolition construction costs, the reduction in waste disposal costs due to the decrease in mixed waste, and the revenue obtained from recycling separated and sorted waste were comprehensively reviewed. It was calculated and analyzed that, compared to general demolition work, a total cost-saving effect of 34,727,000 KRW could be expected. Extrapolating this to the entire nation, based on the year 2020, which had the highest construction waste generation, it is estimated that the social benefits would amount to 746,782,886,000 KRW.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.351-354
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• 2000

In recent years, the world development of alternative construction materials is associated with disposal problems of waste materials as a result of industrial activities. Technologies of refining gypsum to several gypsum modifications ($\alpha$ and $\beta$-hemihydrate) which can be used as construction material in a large scale do actually exist or are under development. This paper provides a technical and economic perspective of the waste gypsum treatment. Especially, several applications particularly of $\alpha$-hemihydrate will be presented, e.g. artificial gypsum aggregate and light-weight masonry units.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.73-74
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• 2023

In this paper, the characteristics of soil concrete were examined using industrial waste red mud and construction waste circulating aggregate, and if unit cement of 250 kg/m³, it can be used as a soil packaging material by meeting the compressive strength standards for parking lots of SPS-KSCICO-001-2006:2020.