• Title/Summary/Keyword: waste concretes

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A Study on Recycle of Waste Concretes for Neutralization and Removal of Heavy Metals ( I ) (페콘크리트의 중화 및 중금속 제거를 위한 재활용에 관한 연구 (I))

  • Kim, Eun-Ho;Kim, Jung-Kwon;Sung, Nak-Chang
    • Journal of Environmental Science International
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    • v.6 no.5
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    • pp.497-503
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    • 1997
  • This study was performed to Investigate the utilization of waste concretes for neutralization and removal of heavy metals In plating wastewater, because waste concretes have been known to be very porous, to have high species surface area and to have alkaline minerals such as calcium. The results obtained from this research showed that waste concretes had a buffer capacity to neutralize an acidic alali system in plating wastewater. Generally, neutralization and removal rate of heavy metals were excellent in the increase of waste concrete amounts and a small size. Because a coefficient of correlation was high, it seemed that removal of heavy metals could be explained by Freundlich and Langmuir isotherms. If we reflected the adsorption capacity(k) and adsorption intensity(1/n) of Freundlich isotherm, we couldn't consider waste concretes as a good adsorbent. But, we could know that waste concretes were capable of removing a part of heavy metals. In point of building waste debris, if waste concretes substituted for a valuable adsorbent such as actuated carbon, they could look forward to an expected economical effect.

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Strength Properties and Durability of Polymer Concrete Using Mixed Waste Plastics (복합재질 폐플라스틱을 재활용한 폴리머콘크리트의 강도 특성 및 내구성)

  • Joo, Myung-Ki;Lee, Youn-Su;Kim, Moon-Chan;Kim, Youn-Hwan
    • Journal of the Korea Concrete Institute
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    • v.18 no.2 s.92
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    • pp.219-226
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    • 2006
  • The effects of binder content and PA content on the flexural, compressive and impact strengths, water absorption and frezzing and thawing of polymer concrete using mixed waste plastics are examined. As a result the flexural, compressive and impact strengths of the polymer concretes using mixed waste plastics tend to increase with increasing binder content and filler content, regardless of the PA content. The flexural, compressive and impact strengths of the polymer concretes using mixed waste plastics decrease with increasing PA content. The water absorption of the polymer concretes using mixed waste Plastics tend to decreased with increasing binder content, regardless of the PA content. The durability factor of the polymer concretes using mixed waste plastics tend to increased with increasing binder content. However, the durability factor of the polymer concretes using mixed waste plastics tend to decreased with increasing PA content.

Properties of Fresh Polymer Concretes Using Mixed Waste Plastics (복합 재질 폐플라스틱을 재활용한 폴리머콘크리트의 경화 전 성질)

  • Joo, Myung-Ki;Lee, Youn-Su;Kim, Moon-Chan;Kim, Youn-Hwan
    • Journal of the Korea Concrete Institute
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    • v.18 no.1 s.91
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    • pp.117-124
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    • 2006
  • The effects of binder content and recycling mixed waste plastics(PA) content on the workability, work life and hardening shrinkage of fresh polymer concrete using mixed waste plastics are examined. As a result, the workability of the polymer concretes using mixed waste plastics tend to improve with increasing binder content, PA content and filler content. The work life of the polymer concretes using mixed waste plastics is shortened with an increase in the initiator content and curing temperature. The length change of the polymer concretes using mixed waste plastics tend to increased with Increasing binder content and PA content. The result of the present research is expected to make a contribution to the recycling of final mixed waste plastics and the continuing efforts for the development of use of the recycled products are thought to expand the horizon for the recycling of the final mixed waste plastics.

Evaluation of Waste Tire Rubber Asphalt Concrete using Polymer Modified Binders (폴리머 개질 폐타이어 아스팔트 콘크리트의 특성 연구)

  • 김광우;이지용;오성균
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1998.10a
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    • pp.180-185
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    • 1998
  • The study was conducted to evaluate the fundamental properties of waste tire asphalt concretes using polymer modified hinder that were made by dry process. The specimens of four types of polymer modified asphalt concretes were prepared, then Marshall test and indirect tensile strength tests were performed on these samples. The results showed that polymer modified waste tire rubber asphalt concrete was acceptable for the material of asphalt pavement surface layer.

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Usage potential of recycled aggregates in mortar and concrete

  • Yaragal, Subhash C.;Muhammad, Roshan A.K.
    • Advances in concrete construction
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    • v.5 no.3
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    • pp.201-219
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    • 2017
  • With the rapid growth in construction sector, it becomes all the more important to assess the amount of Construction and Demolition (C&D) waste being generated and analyze the practices needed to handle and use this waste before final disposal. This serves waste management and disposal issues, paving way to waste utilization in construction industry from the sustainability point of view. C&D waste constitutes a major bulk of total solid waste produced in the world. In this work, an attempt is made to study the performance of concrete using water soaked Recycled Coarse Aggregates (RCA) in replacement levels of 0%, 25%, 50%, 75% and 100% to Natural Coarse Aggregates (NCA). Experiments were designed and conducted to study the performance of RCA based concrete. Further suitable performance enhancement techniques to RCA based concrete were attempted, to achieve compressive strength at least equal to or more than that for no RCA based concrete (control concrete). Performance enhancement study is reported here for 50% and 100% RCA based concretes. All four techniques attempted have given favorable results encouraging use of RCA based concretes with full replacement levels, to adopt RCA based concrete in structural applications, without any kind of concern to the stake holder. Further attempts have also been made to use Recycled Fine Aggregates (RFA) with appropriate modifications to serve as fine aggregates in mortar and concrete. Using RFA blended with river sand fractions as well as RFA with Iron Ore Tailings (IOT) fractions, have given good results to serve as fine aggregates to the extent of 100% replacement levels in mortars and concretes.

Problems in Strength Characteristics of Recycled Waste Concrete (폐콘크리트 재활용에 있어서 강도특성상의 문제점)

  • 김광우;연규석;이병덕
    • Proceedings of the Korea Concrete Institute Conference
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    • 1992.10a
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    • pp.44-49
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    • 1992
  • Selected strength characteristics of recycled concrete using crushed waste concrete were compared with those of conventional concrete using natural aggregate. Compressive strength, bonding at the interface between recycled aggregate and fresh mortar, strain and deflection under three-point bending were evaluated. Recycled concrete, in general, showed lower compressive strength, lower edlastic modulus, higher stain and higher deflection under the same loading level, compared with those of conventional concretes. However, the strength retaining ratios of recycled concretes were higher than those of conventional concretes. The compressive strength which is one of the most important load carrying capacities of concrete should be improved for successful re-use of waste concrete in structural concrete.

Strength Characteristics of No-Fine Concrete Containing Recycled Aggregates (재생골재를 함유한 무잔골재 콘크리트의 강도특성)

  • 김태근;이광명;김낙경;고용일
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10c
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    • pp.1-6
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    • 1998
  • Recently, as to destruction and renovation of aged building, waste concretes have been reclaimed near foreshore and filled up underground. Recycling demolished concrete as aggregate helps to settle economic and environmental problems of obtaining superior aggregates from natural sources and to dispose waste concretes. An experimental study was carried out to investigate the strength characteristics of no-fine concrete containing recycled aggregates. The cement-aggregate weight ratios of 1: 5, 1: 6, 1: 7 and water-cement ratios of 30, 35, 40, 45% were chosen for the mix design of no-fine concretes. The compressive and splitting tensile strength at 7 and 28 days were measured for 12 different mixes. On the basis of test results, the optimum mix proportion of no-fine concrete containing recycled aggregates was determined and applied to the production of retaining wall block.

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A Study for Developing Construction Goods by Waste-Concrete (폐콘크리트를 이용한 건자재 상품화 개발은 위한 연구)

  • 남기룡;서치호;이광명;이건영;최경선
    • Proceedings of the Korea Concrete Institute Conference
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    • 1996.10a
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    • pp.64-69
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    • 1996
  • As Waste-concretes generated in construction field are increasing, it is becoming difficult and expensive to dispose them. For environmental reasons, many attempts have been made to find ways of reusing these materials. However, very little waste-concrete is currently recycled or reused anywhere on the world. Recycled concrete is mainly used as nonstabilized base of sub-base in highway construction. In this study, in order to promote the reuse of the waste-concretes, no-fines concrete blocks using recycled concrete aggregates were produced and their properties are evaluated. From the test results about strengths, pemeability, and durability, it is known that to use recycled aggregates for construction goods is promising and economical.

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Incorporation of marble waste as sand in formulation of self-compacting concrete

  • Djebien, Rachid;Hebhoub, Houria;Belachia, Mouloud;Berdoudi, Said;Kherraf, Leila
    • Structural Engineering and Mechanics
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    • v.67 no.1
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    • pp.87-91
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    • 2018
  • Concrete is the most widely used building material all over the world, because of its many technical and economic qualities. This pressure on the concrete resource causes an intensive exploitation of the quarries of aggregates, which results in a exhaustion of these and environmental problems. That is why recycling and valorization of materials are considered as future solutions, to fill the deficit between production and consumption and to protect the environment. This study is part of the valorization process of local materials, which aims to reuse marble waste as fine aggregate (excess loads of marble waste exposed to bad weather conditions) available in the marble quarry of Fil-fila (Skikda, East of Algeria) in the manufacture of self-compacting concretes. It consists of introducing the marble waste as sand into the self-compacting concrete formulation, with variable percentages (25%, 50%, 75% and 100%) and to study the development of its properties both in fresh state (air content, density, slump flow, V-funnel, L-box and sieve stability) as well as the hardened one (compressive strength and flexural strength). The results obtained showed us that marble wastes can be used as sand in the manufacture of self compacting concretes.

Assessment of Applicability of Waste Vinyl Asphalt Concretes (폐비닐 아스팔트 콘크리트의 현장 적응성 연구)

  • Kim, Kwang-Woo;Li, Xiang-Fan;Lee, Soon-Jae;Kim, Sung-Un
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2001.10a
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    • pp.111-114
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    • 2001
  • This study is a fundamental research for recycling waste vinyl in asphalt concrete mixture for roadway pavement. The mixing method and proper content of waste polyethylene(PE) film were determined through preliminary mix design. This study used 2-type aggregate gradations and two-type waste PE films. The mixtures were applied for a test pavement on a rural road. Quality evaluation of the asphalt concrete confirmed that waste vinyl asphalt concrete was applicable to road pavement.

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