• Title/Summary/Keyword: concrete products

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Strength enhancement of concrete incorporating alccofine and SNF based admixture

  • Reddy, Panga Narasimha;Jindal, Bharat Bhushan;Kavyateja, Bode Venkata;Reddy, A. Narender
    • Advances in concrete construction
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    • v.9 no.4
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    • pp.345-354
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    • 2020
  • Cement is the most significant component in concrete. Large scale manufacturing of cement consumes more energy and release harmful products (Carbon dioxide) into the atmosphere that adversely affect the environment and depletes the natural resources. A lot of research is going on in globally concentrating on the recycling and reuse of waste materials from many industries. A major share of research is focused on finding cementitious materials alternatives to ordinary Portland cement. Many industrial waste by-products such as quartz powder, metakaolin, ground granulated blast furnace slag, silica fume, and fly ash etc. are under investigations for replacement of cement in concrete to minimize greenhouse gases and improve the sustainable construction. In current research, the effects of a new generation, ultra-fine material i.e., alccofine which is obtained from ground granulated blast furnace slag are studied as partial replacement by 25% and with varying amounts of sulfonated naphthalene formaldehyde (i.e., 0.3%, 0.35% and 0.40%) on mechanical, water absorption, thermal and microstructural properties of concrete. The results showed moderate improvement in all concrete properties. Addition of SNF with combination of alccofine showed a significant enhancement in fresh, hardened properties and water absorption test as well as thermal and microstructural properties of concrete.

Effect of Rebar Corrosion on the Onset of Cracks in Cover Concrete (철근부식에 의한 콘크리트의 균열발생에 관한 연구)

  • 이한승
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.771-774
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    • 1999
  • This study was carried out to quantitatively investigate the amount of corrosion at the time of onset of cracks in cover concrete due to rebar corrosion. In this experiments, the accelerated galvanostatic corrosion method was carried out. FEM analyses were also conducted to investigate the expansive behaviors due to rebar corrosion and the mechanical properties of corrosion products. As a result, it was concluded that the corrosion ratio at the time of onset of cracks in cover concrete was 3% by weight. The onset of cracks in cover concrete due to rebar corrosion could be analyzed by the finite element method.

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염용액에 침지한 콘크리트의 열화에 대한 연구

  • 문한영;김기형;김성수
    • Proceedings of the Korea Concrete Institute Conference
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    • 1989.10a
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    • pp.25-30
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    • 1989
  • In this paper, morter and concrete specimens made with four cements were immersed in Mgcl2, MgSO4 Solution and artifical Seawater which was corresponded with Seawater. The hydration products of immersed cement pastes were looked over by using SEM, EDS and X-ray diffraction method. The results show that the concrete made with domestic flyash cement and blast-frrnace slag cement is superior to that of ordinary portland cement in resistance to chloride and sulphate solution. Especially, it is found that the attack of Cl-ion on the concrete plays an important role of the deterioration of concrete.

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High Strengthening Mechanism by Blast Furnace Slag in Concrete Based Products (고로슬래그 미분말을 사용한 콘크리트 2차 제품의 고강도화 메커니즘)

  • Kim, Jin-Man;Cho, Sung-Hyun;Lee, Dae-Kyung
    • Clean Technology
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    • v.7 no.2
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    • pp.109-117
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    • 2001
  • Whereas commonly used to make concrete having rich water contents as binder or mineral admixture, blast furnace slag has been rarely applied to manufacture in concrete based products having poor water contents. This study, for the multi-recycling of blast furnace slag, is to analyze strength enhancement mechanism of concrete based products using blast furnace slag. The results of this study are following. We found that blast furnace slag is very effective mineral admixture to manufacture high strength spacer having over $400kgf/cm^2$ in compressive strength. Also, enhancement of strength by blast-furnace slag are responsible to densified grading and pozzolanic reaction.

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A Review of Physical Properties of Cement-Free Precast Concrete Using Industrial By-Products (산업부산물을 적용한 무 시멘트 프리캐스트 콘크리트의 물리적 특성 검토)

  • Jung, Young-Woong;Yun, Ja-Yeon;Shin, Kyung-Su;Lee, Taegyu;Choi, Hyeonggil
    • Journal of the Korea Institute of Building Construction
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    • v.24 no.3
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    • pp.309-318
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    • 2024
  • This research investigated the feasibility of incorporating industrial by-products into precast concrete formulated with blast furnace slag and natural gypsum. Specifically, the study examined the effects of incorporating steelmaking slag(STS slag), combined heat power plant fly ash, and return dust. The optimal amount of these by-products was determined by measuring air content, slump, and compressive strength at various incorporation levels. Results demonstrated that compressive strength was enhanced across all levels of by-product addition. Notably, incorporating 10% of the by-products led to exceptional early-age strength development. However, a 20% addition of combined heat power plant ash significantly reduced the slump value by approximately 40%. Considering these findings and the requirement for rapid strength development in precast concrete applications, a 10% incorporation of industrial by-products was deemed optimal due to its ability to accelerate early-age strength gain.

The Comparative Study on the Environmental Impact Assessment of Construction Material through the Application of Carbon Reducing Element - Focused on Global Warming Potential of Concrete Products- (탄소저감요소를 적용한 건설재료의 환경영향평가 비교 연구 - 콘크리트 제품 생산단계에서의 지구온난화 영향을 중심으로-)

  • Cho, Su-Hyun;Chae, Chang-U
    • KIEAE Journal
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    • v.15 no.1
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    • pp.147-154
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    • 2015
  • Environmental impact assessment techniques have been developed as a result of the worldwide efforts to reduce the environmental impact of global warming. By using the quantification method in the construction industry, it is now possible to manage the greenhouse gas is to systematically evaluate the impact on the environment over the entire construction process. In particular, the proportion of greenhouse gas emissions at the production stage of construction material occupied is high, and efforts are needed in the construction field. In this study, intended for concrete products for the construction materials, by using the LCA evaluation method, we compared the results of environmental impact assessment and carbon emissions of developing products that have been applied low-carbon technologies compared to existing products. As a result, by introducing a raw material of industrial waste, showed carbon reduction. Through a comparison of the carbon emission reduction effect of low-carbon technologies, it is intended to provide academic data for the evaluation of greenhouse gases in the construction sector and the development of low-carbon technologies of the future.

The Study on the Concrete Precast Block using Coal-ash Artificial Aggregate (석탄회 인공골재를 이용한 콘크리트 프리캐스트 블록 연구)

  • 조병완;박승국;김진일
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.10a
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    • pp.293-298
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    • 2002
  • Recycling of coal combustion by-product(Ash) are becoming more improtant in the utilization business as a result of the increased use of NOx reduction technologies at coal-fired power plants. current disposal methods of these by-products create not only a loss of profit for the power industry, but also environmental concerns that breed negative public opinion. This research made concrete crecast block using coal ash artificial aggregate for environmental-friendly products and compared strength special quality of this block with existent common use brick and analyzed application possibility in situ with a reserve experiment that measured strength property and manufactured method to handle coal ash produced in Bo-ryung thermoelectric power plant.

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A study on the development of self-healing concrete and repair materials with the resistance to sulfuric acid attack (내황산성 자기치유 콘크리트 및 단면복구재 개발에 관한 연구)

  • Bang, Sin-Young;Kim, Jeong-Mi;Ahn, Tae-Ho
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.05a
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    • pp.84-85
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    • 2015
  • The aim of this study is to develop crack self-healing concrete and repair materials with the sulfate resistance using geo-materials and by-products for practical industrial application. Research has been done on the healing of cracks in aged concrete, but it seems that very little is known about the actual healing mechanism and its conditions. In this research, the essential properties of geo-materials with pozzolanic reaction for self-healing were analyzed and discussed.

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Products & Execution of Exposed Concrete of Incheon Stadium (인천월드컵경기장 노출 콘크리트 시공사례)

  • 윤여진
    • Magazine of the Korea Concrete Institute
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    • v.14 no.6
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    • pp.102-106
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    • 2002
  • 인천문학경기장은 인천시 남구 문학동산 8번지 일대 44만 1,628$m^2$(13만 3,592평) 대지 위에 약 5만 2,000석 규모의 주경기장과 3만석 규모의 야구장 및 실내수영장, 실내체육관 및 4,600대 규모의 지하주차장으로 시공된 종합 스포츠 타운이다.(중략)

Rheological Model of Flowable Concrete Considering with Mix Conditions (배합조건에 따른 유동콘크리트의 레올로지 특성모델)

  • Cho, Chang-Geun;Choi, Yeol;Kim, Wha-Jung;Kim, Jeong-Seop
    • Proceedings of the Korea Concrete Institute Conference
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    • 2009.05a
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    • pp.251-252
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    • 2009
  • Rheological characteristics of flowable concrete manufactured in domestic products of cement, aggregates, and SP admixtures were investigated by experiments and the predictive model of rheological characteristics of flowable concrete has been newly proposed considering with the effects of the W/C ratio and the dosage of SP admixture.

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