• Title/Summary/Keyword: optimum coarseness factor

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Fundamental Study on Optimum Mixing Proportion of Cement Concrete Pavement using Recycled Aggregate (순환골재를 활용한 포장용 시멘트콘크리트의 최적배합 도출을 위한 기초 연구)

  • Kim, Sueng Won;Kim, Yong Jae;Lee, Jang Yong;Lee, Hak Yong;Park, Cheol Woo
    • International Journal of Highway Engineering
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    • v.18 no.6
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    • pp.105-113
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    • 2016
  • OBJECTIVES : This study is to develop the optimum mixing proportions for cement concrete pavement with using recycled aggregates. METHODS : The mixture varied recycled coarse aggregates content from 50 % to 100 % to replace the natural coarse aggregates by weight. Tests for fundamental properties as a cement concrete pavement were conducted before and after hardening of the concrete. RESULTS : It was found that the variation in the amount of the recycled aggregate affected the compressive and flexural strength development, as well as the chloride ion penetration resistance. As the amount of the recycled aggregate content increased the compressive and flexural strength and the resistance to chloride ion penetration decreased. However, the resistance to freeze-thaw reaction was affected significantly. In addition, the gradation of the aggregate became worse and hence so did the coarseness factor as the recycled aggregate amount increased. CONCLUSIONS : The fundamental properties of the concrete with recycled aggregate does not seem to be appropriate when the recycled aggregate quality is not guaranteed up to a some level and its replacement ratio is over 50%. The optimized gradation of the aggregates should also be sought when the recycled aggregate is used for the cement concrete pavement materials.