• 한국산학기술학회논문지
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• 제2권2호
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• pp.65-71
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• 2001

폐아스팔트혼합물의 배출은 좁은 도로와 늘어나는 교통량에 의해 해마다 그 양이 증가하고 있으며 건설폐기물 중에 그 오염도가 다른 폐기물에 비하여 매우 심각하다고 할 수 있다. 특히 폐아스팔트혼합물의 경우 단순히 환경오염 차원을 넘어 무단 투기되므로 국민의 식수원을 오염시켜 사회적 문제로 대두되고 있는 실정으로 국내의 실정을 감안할 때 천연자원의 보존, 막대한 처리비용 절감 및 환경보전이라는 측면에서도 막대한 양의 폐아스팔트혼합물에 대하여 가열 및 상온 아스팔트재활용과 처리에 대한 중요성을 실감할 수가 있다. 본 연구에서는 가열의 공정을 생략하고 이러한 단점들을 제거하여 폐아스팔트혼합물의 재활용 취지에 좀더 가까운 결과를 유도할 수 있는 상온 아스팔트 재활용에 관하여 상온재활용 및 처리기술의 개발 및 상온재생 방법의 실험적인 연구를 통하여 그 적용성 및 적합성을 검토하고자 한다.

• 한국도로학회논문집
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• 제20권1호
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• pp.27-33
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• 2018

PURPOSES : The purpose of this study is to estimate the optimum content of an inorganic additive for cold-recycled asphalt mixtures and evaluate its performance. METHODS : An indirect tensile test, a tensile-strength ratio test, and an indirect tensile-fatigue test were conducted on cold-recycling asphalt mixtures with various additives. RESULTS : The laboratory performance tests indicated that granulated blast-furnace slag mixed with inorganic and cement activators provided optimum performance. The performance results of the cold-recycled asphalt pavement were similar to the inorganic and cement activators' performance in terms of the indirect tensile strength, tensile strength ratio, and indirect tensile-fatigue test. CONCLUSIONS : Overall, the performance of a cold-recycled asphalt mixture using inorganic additives and emulsion asphalt was comparable to a warm-recycled asphalt mixture. However, more experiments aimed at improving its performance and studying the effect of the inorganic additives must be conducted.

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 1996년도 춘계학술발표회 연구발표개요집 DIGESTS OF THE 1996 SPRING CONFERENCE
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• pp.11-43
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• 1996

• 한국도로학회:학술대회논문집
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• 한국도로학회 2008년도 추계학술대회 논문집
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• pp.251-257
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• 2008

• 자원리싸이클링
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• 제8권4호
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• pp.30-38
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• 1999

제철공정의 더스트류로부터 제조된 비소성펠릿의 고로 조업의 가능성을 파악하기 위해서 다음과 같은 고온특성을 조사하였다. 고로용 CBP는 상온강도 외에 고온특성기준을 추가하여 검토한 결과, 다음과 같은 결과를 얻을 수 있었다. CBP의 염기도는 1.7 전후가 적절한 고온특성을 나타내었으며, 결합제로서 포틀랜드계 보다는 수재 슬래그계 시멘트가 우수한 용융특성에 적절함을 확인하였다. 또한 연화-용융사이의 압손누적량 기준으로 볼 때 염기도 2.6이상의 CBP는 노내에서 통기성 악화 가능성을 나타내었다. 따라서 결합제의 종류보다는 기본적으로 염기도 관리가 중요하며 결합제는 펠릿의 압축강도 및 양생시간등을 고려하여 선택할 필요가 있음을 확인할 수 있었다.

• 한국도로학회논문집
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• 제20권1호
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• pp.69-76
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• 2018

PURPOSES : This study determined the optimal usage rate of RAP (reclaimed asphalt pavement) using cold central-plant recycling (CCPR) on a road-surface layer. In addition, a mixture-aggregate gradation design and a curing method based on the proposed rate for the surface-layer mix design were proposed. METHODS : First, current research trends were investigated by analyzing the optimum moisture content, mix design, and quality standards for surface layers in Korea and abroad. To analyze the aggregate characteristics of the RAP, its aggregate-size characteristics were analyzed through the combustion asphalt content test and the aggregate sieve analysis test. Moreover, aggregate-segregation experiments were performed to examine the possibility of RAP aggregate segregation from field compaction and vehicle traffic. After confirming the RAP quality standards, coarse aggregate and fine aggregate, aggregate-gradation design and quality tests were conducted for mixtures with 40% and 50% RAP usage. The optimum moisture content of the surface-layer mixture containing RAP was tested, as was the evapotranspiration effect on the surface-layer mixture of the optimum moisture content. RESULTS : After analyzing the RAP recycled aggregate size and extraction aggregate size, 13-8mm aggregate was found to be mostly 8mm aggregate after combustion. After using surface-chipping and mixing methods to examine the possibility of RAP aggregate segregation, it was found that the mixing method contributed very little for 3.32%, and because the surface-chipping method applied compaction energy directly as the maximum assumption the separation ratio was 15.46%. However, the composite aggregate gradation did not change. Using a 40% RAP aggregate rate on the surface-layer mixture for cold central-plant recycling satisfied the Abroad quality standard. The optimum moisture content of the surface-layer mixture was found to be 7.9% using the modified Marshall compaction test. It was found that the mixture was over 90% cured after curing at $60^{\circ}C$ for two days. CONCLUSIONS : To use the cold central-plant recycling mixture on a road-surface layer, a mixture-aggregate gradation design was proposed as the RAP recycled aggregate size without considering aggregate segregation, and the RAP optimal usage rate was 40%. In addition, the modified Marshall compaction test was used to determine the optimum moisture content as a mix-design parameter, and the curing method was adapted using the method recommended by Asphalt Recycling & Reclaiming Association (ARRA).

• 한국도로학회논문집
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• 제20권1호
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• pp.47-58
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• 2018

PURPOSES : The purpose of this study is to evaluate the mechanical properties of a cold-recycling asphalt mixture used as a base layer and to determine the optimum emulsified-asphalt content for ensuring the mixture's performance. METHODS : The physical properties (storage stability, mixability, and workability) of three types of asphalt emulsion (CMS-1h, CSS-1h, and CSS-1hp) were evaluated using the rotational viscosity test. Asphalt emulsion residues, prepared according to the ASTM D 7497-09 standard, were evaluated for their rheological properties, including the $G*/sin{\delta}$and the dynamic shear modulus (${\mid}G*{\mid}$). In addition, the Marshall stability, indirect tensile strength, and tensile-strength ratio (TSR) were evaluated for the cold-recycling asphalt mixtures fabricated according to the type and contents of the emulsified asphalt. RESULTS : The CSS-1hp was found to be superior to the other two types in terms of storage stability, mixability, and workability, and its $G*/sin{\delta}$ value at high temperatures was higher than that of the other two types. From the dynamic shear modulus test, the CSS-1hp was also found to be superior to the other two types, with respect to low-temperature cracking and rutting resistance. The mixture test indicated that the indirect tensile strength and TSR increased with the increasing emulsified-asphalt content. However, the mixtures with one-percent emulsified-asphalt content did not meet the national specification in terms of the aggregate coverage (over 50%) and the indirect tensile strength (more than 0.4 MPa). CONCLUSIONS : The emulsified-asphalt performance varied greatly, depending on the type of base material and modifying additives; therefore, it is considered that this will have a great effect on the performance of the cold-recycling asphalt pavement. As the emulsified-asphalt content increased, the strength change was significant. Therefore, it is desirable to apply the strength properties as a factor for determining the optimum emulsified-asphalt content in the mix design. The 1% emulsified-asphalt content did not satisfy the strength and aggregate coverage criteria suggested by national standards. Therefore, the minimum emulsified-asphalt content should be specified to secure the performance.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.173-178
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• 2001

The materials processing factors such as remelting and casting, heat treatment and microstructure, sheet rolling and can body forming in the aluminum can-to-can recycling procedure have been investigated. Aluminum used beverage can(UBC) was remelted together with virgin aluminum. The ceramic filter was used during casting to remove large impurities. As-cast microstructure was composed of large intermetallic compound (mainly $\beta$ -phase) distributed in the aluminum matrix. By heat treatment, $\beta$ -phase was transformed to $\alpha$ -phase which was also formed from $Mg_2$Si particles. The heat treated ingots were hot-rolled at 48$0^{\circ}C$ and cold-rolled to thin sheets. Can making from this thin sheets was successful and earing was measured after can making. There was a critical cold reduction rate for minimum earing. Some cracks were initiated from the impurity particles which was not removed during filtering.

• 한국전기전자재료학회논문지
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• 제26권5호
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• pp.415-420
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• 2013

The new recycling technology for aged Aluminum wires in overhead conductor have been carried out. We are attempting to develop remanufacturing method for them for more effective way of recycling in stead of its conventional remelting process. The weld of aged aluminum wires play a vital role in remanufacture process. The paper investigates the mechanical properties during cold welding process of aged Aluminum wire. The tensile tests and microscopic analysis results are discussed to underscore the hardening features of welded aluminum wire. Various graphs are presented accompanied by discussion about their relevance on the process.

• 자원리싸이클링
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• 제4권1호
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• pp.60-68
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• 1995

철강공정에서 발생하는 함철더스트에 시멘트를 첨가한 비소성 더스트 펠릿을 제조하여 고로용으로서의 특성을 평가하였다. 시멘트를 10wt.% 첨가한 펠릿은 적절한 양생조건하에서 150kg/p 이상의 압축강도에 도달하였다. 더스트 펠릿은 특히 $900^{\circ}C$에서의 환원성이 우수하였는데, 이는 비소성 펠릿 중에 함유된 탄소의 직접환원 반응과 고온에서 증가된 기공 때문이다. 이외에 비소성 펠릿의 회전강도, 환원분화성 및 환원 팽창성도 철광석 소결광 및 소성 펠릿에 비교하여 우수하거나 대등한 성상을 나타내는 것을 확인하였다.