• Title/Summary/Keyword: concrete materials

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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.

Applications of Artificial Neural Networks for Using High Performance Concrete (고성능 콘크리트의 활용을 위한 신경망의 적용)

  • Yang, Seung-Il;Yoon, Young-Soo;Lee, Seung-Hoon;Kim, Gyu-Dong
    • Journal of the Korean Society of Hazard Mitigation
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    • v.3 no.4 s.11
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    • pp.119-129
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    • 2003
  • Concrete and steel are essential structural materials in the construction. But, concrete, different from steel, consists of many materials and is affected by many factors such as properties of materials, site environmental situations, and skill of constructors. Concrete have two kinds of properties, immediately knowing properties such as slump, air contents and time dependent one like strength. Therefore, concrete mixes depend on experiences of experts. However, at point of time using High Performance Concrete, new method is wanted because of more ingredients like mineral and chemical admixtures and lack of data. Artificial Neural Networks(ANN) are a mimic models of human brain to solve a complex nonlinear problem. They are powerful pattern recognizers and classifiers, also their computing abilities have been proven in the fields of prediction, estimation and pattern recognition. Here, among them, the back propagation network and radial basis function network ate used. Compositions of high-performance concrete mixes are eight components(water, cement, fine aggregate, coarse aggregate, fly ash, silica fume, superplasticizer and air-entrainer). Compressive strength, slump, and air contents are measured. The results show that neural networks are proper tools to minimize the uncertainties of the design of concrete mixtures.

Impact of aggressive exposure conditions on sustainable durability, strength development and chloride diffusivity of high performance concrete

  • Al-Bahar, Suad;Husain, A.
    • Structural Monitoring and Maintenance
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    • v.2 no.1
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    • pp.35-48
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    • 2015
  • The main objective of this study is to evaluate the long-term performance of various concrete composites in natural marine environment prevailing in the Gulf region. Durability assessment studies of such nature are usually carried out under aggressive environments that constitute seawater, chloride and sulfate laden soils and wind, and groundwater conditions. These studies are very vital for sustainable development of marine and off shore reinforced concrete structures of industrial design such as petroleum installations. First round of testing and evaluation, which is presented in this paper, were performed by standard tests under laboratory conditions. Laboratory results presented in this paper will be corroborated with test outcome of ongoing three years field exposure conditions. The field study will include different parameters of investigation for high performance concrete including corrosion inhibitors, type of reinforcement, natural and industrial pozzolanic additives, water to cement ratio, water type, cover thickness, curing conditions, and concrete coatings. Like the laboratory specimens, samples in the field will be monitored for corrosion induced deterioration signs and for any signs of failureover initial period ofthree years. In this paper, laboratory results pertaining to microsilica (SF), ground granulated blast furnace slag (GGBS), epoxy coated rebars and calcium nitrite corrosion inhibitor are very conclusive. Results affirmed that the supplementary cementing materials such as GGBS and SF significantly impacted and enhanced concrete resistivity to chloride ions penetration and hence decrease the corrosion activities on steel bars protected by such concretes. As for epoxy coated rebars applications under high chloride laden conditions, results showed great concern to integrity of the epoxy coating layer on the bar and its stability. On the other hand corrosion inhibiting admixtures such as calcium nitrite proved to be more effective when used in combination with the pozzolanic additives such as GGBS and microsilica.

Evaluation of Diffusion on Cement Mortar and Durability of Concrete Specimen Using Inorganic Coating Material and Surface Treatment System (무기질 도료 및 표면처리 시스템을 적용한 시멘트 모르타르와 콘크리트의 내구성 평가)

  • Kim, In-Seob;Lee, Jong-Kyu;Chu, Yong-Sik;Kim, Tae-Hyun;Shim, Kwang-Bo
    • Journal of the Korea Concrete Institute
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    • v.15 no.4
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    • pp.522-528
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    • 2003
  • Concrete has been considered as a semi-permanent structural material, because its excellent durability. However, such high durable structure is often attacked by some environmental condition such as chloride diffusion, carbonation and so on. In order to prevent the deterioration behaviors of concrete structures. We estimated durability of concrete when used surface treatment system and coatings by new type inorganic coating materials. Base on the results of chloride ion's diffusion test, the coated cement mortar had smaller transmitted quantity.