• Elastomers and Composites
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• 제32권5호
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• pp.325-329
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• 1997

Microbial treatment of the powdered waste tire was studied to recycle the waste tires. Chemoautotrophic acidophilic, iron-oxidizing bacterium was employed to unvulcanize the powdered tires. Biotreated rubber powder was compared to a untreated and a chemically treated powder. The results showed sulfur content of rubber powder(1.33%) were decreased to 1.22% by chemical treatment and 1.12% by microbial treatment for 20 days, 0.88%, for 30 days. One of the problems of the powdered utilization of the waste tires is that rubber powder leads to decrease mechanical properties when it is compounded with other virgin polymers. When tee biotreated powder was compounded with natural rubber, the mechanical properties were less decreased when untreated or chemically treated powder. Therefore, the microbial treatment can be one of useful methods to recycle the waste tire.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 추계 학술논문 발표대회
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• pp.128-129
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• 2015

Recently, a number of problems due to the CO₂ emissions are occurred. Therefore, it is a movement to restrict this activity. The research is being carried out steadily for recycling waste concrete from the cement paste based fine powder, which accounts for over 60% of construction waste as a recycled cement. In this study, the conclusion was obtained as a result of the research conducted, and then, replacing the main material of cement concrete to solve the above problem by reducing the amount of cement used Waste Concrete Powder. The more concrete results page replacement ratio of fine powder increases, the flow value of the concrete is lowered, the strength was remarkably reduced when the page Concrete Powder.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.81-87
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• 2003

The purpose of this study is the development of a recycling process to recover the hydrated ability of cement hydrate which accounts for a large proportion of cementitious powder by concrete waste in order to recycle cementitious powder by concrete waste as recycle cement. Therefore, after having theoretical consideration based on the properties of high-heated concrete, we consider the properties of hydration of cementitious powder in hardened mortar under various temperature conditions. As a result of experiment, it is revealed that an effective development of recycling cement is possible since the cementitious powder by concrete waste recovers a hydraulic property during burning at $600^{\circ}C$ or $700^{\circ}C$. And it is shown that the fluidity of mortar decreases rapidly as the burning temperature of recycle cement increases. however, the improved effect of fluidity is predominant if adding the additive such as fly-ash or blast furnace slag.

• 농업과학연구
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• 제47권1호
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• pp.193-204
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• 2020

This experiment was conducted to study the effect of organic fertilizer on the growth of Peucedanum japonicum Thunberg and the change of soil chemical characteristics. The organic matter contents of coffee sludge and dried food waste powder were 44.26 and 51.18%, respectively. These values exceed the organic matter content of organic fertilizers recommended by the Rural Development Administration (RDA) of South Korea by more than 30%. Accordingly, they indicate the possibility of their use as organic fertilizers. The results from the analysis of soil properties after cultivation showed that the organic matter content of coffee sludge amended soils was two-fold higher than that of dried food waste powder amended soils. However, the content of available phosphorus was two times lower in the coffee sludge amendments. It is expected that the dried food waste powder was actively used to decompose organic substances, and that phosphoric acid was added by the soil microorganisms used to decompose organic substances. In terms of Peucedanum japonicum Thunberg growth, leaf discoloration was observed for all treatments except with the standard rate of dried food waste powder. The standard rate of dried food waste powder also produced relatively better results than other treatments with regard to other growth characteristics such as root length (34.08 cm), root diameter (0.78 cm), and fresh root weight (4.77 g plant^-1). Therefore, the standard rate of dried food waste powder produced better results than other treatments and can be used as an organic fertilizer in the growth of Peucedanum japonicum Thunberg.

• 대한토목학회논문집
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• 제28권4C호
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• pp.247-253
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• 2008

본 연구에서는 준설토, 폐타이어 분말 및 저회(bottom ash)를 재활용한 폐타이어 분말 혼합경량토의 역학적 특성을 고찰하였다. 본 실험에서 폐타이어 분말의 함량은 건조 준설토 중량대비 0%에서 100%까지 25%간격으로 변화시켜 5개의 공시체를 준비하였다. 혼합된 공시체는 일축압축시험, 탄성파 시험을 수행하여 강도와 지반정수들을 구하였다. 실험결과 폐타이어 함량이 증가함에 따라 일축압축강도와 단위중량은 감소하는 경향을 나타내었다. 그러나 파괴시 축변형률은 증가하는 것으로 나타났다. 또한 폐타이어 분말의 함량이 증가할수록 폐타이어 혼합경량토의 응력-변형률 곡선은 취성적 거동보다는 연성적 거동을 나타내었다. 탄성파 시험에서는 폐타이어 함량이 증가함에 따라 탄성파 속도와 전단탄성계수는 감소하는 성질을 나타내고 있다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.139-142
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• 1999

The purpose of this experimental research is to investigate the mechanical properties of ordinary strength and high strength concrete containing waste glass powder. For this purpose, after production of concrete containing waste glass powder for different unit weight of binder and placement ratio of waste glass powder, optimum mixing proportions of them was determined, and then mechanical properties such as static modulus of elasticity as well as compressive, tensile and flexural strength were tested and analyzed for concrete produced according to optimum mixing proportions. As a result, the concrete containing waste glass powder has as excellent workability and strength, it's strengths are analogus to those of silica fume, it's workability is somewhat better than that of silica fume.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.252-253
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• 2014

This study is to XRD and image analysis of low carbon type recycled cement from waste concrete powder and cement raw materials. Waste concrete powder possible to low carbon type recycled cement in small part of additive materials. Also, low carbon type recycled cement using waste concrete powder is suitable for ordinary portland cement.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.191-192
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• 2016

Recently, there have been many studies about recycling cementitious powder from concrete waste, generated after recycle aggregate production. Previous studies showed that when the heating process of waste powder in paste is dehydrated making possible the restoration of hydraulic properties. Thus the purpose of this study is to make an experimental review on properties of concrete products made vibration-compressive according to waste concrete powder.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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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.

• Computers and Concrete
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• 제21권3호
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• pp.311-319
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• 2018

This study used a volumetric method for design. The control group used waste Liquid Crystal Displayplay (LCD) glass powder to replace cement (0%, 10%, 20%, 30%), and the PZT group used Pd-Zr-Ti piezoelectric (PZT) powder to replace 5% of the fine aggregate to make cement mortar. The engineering and the mechanical and electricity properties were tested; flow, compressive strength, ultrasonic pulse velocity (UPV), water absorption and resistivity (SSD and OD electricity at 50 V and 100 V) were determined; and the correlations were determined by linear regression. The compressive strength of the control group (29.5-31.8 MPa) was higher than that of the PZT group (25.1-29 MPa) by 2.8-4.4 MPa at the curing age of 28 days. A 20% waste LCD glass powder replacement (31.8 MPa) can fill up finer pores and accelerate hydration. The control group had a higher 50 V-SSD resistivity ($1870-3244{\Omega}.cm$), and the PZT group had a lower resistivity ($1419-3013{\Omega}.cm$), meaning that the resistivity increases with the replacement of waste LCD glass powder. This is because the waste LCD glass powder contains 62% $SiO_2$, which is a low dielectric material that is an insulator. Therefore, the resistivity increases with the $SiO_2$ content.