• 제목/요약/키워드: Relative dynamic modulus of elasticity(RDME)

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Performance of paraffin mixed concrete subjected to combined freeze-thaw and chloride environment

  • Hiroshi Maruta;Dhruva Narayana Katpady;Hirotaka Hazehara;Masashi Soeda
    • Advances in concrete construction
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    • 제17권1호
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    • pp.45-52
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    • 2024
  • In this study, the fresh properties of paraffin-mixed concrete, compressive strength, resistance to frost damage, and resistance to composite deterioration under freeze-thaw and salt environment were investigated. The compressive strength of paraffin-mixed concrete was almost the same as that of unmixed concrete, and no decrease in strength was observed, unlike the concrete with entrained air in consideration of freeze-thaw resistance. Concerning the freeze-thaw resistance of paraffin-mixed concrete, the relative dynamic modulus of elasticity (RDME) did not decrease even without entrained air. In addition, no decrease in the RDME was observed in the combined deterioration with salt damage, and it was confirmed that the mass reduction was suppressed compared to the concrete without paraffin. The freeze-thaw resistance of concrete when paraffin is mixed may be improved due to the reduction in the amount of frozen water and the mixed paraffin particles exist in the concrete as pore fillers with a size of 200 ㎛ or less, which act as substitutes for air voids. This resulted in reduction of the apparent air void spacing and thereby relieving the pore pressure.

인공신경망 기반 동결융해 작용을 받는 콘크리트의 내구성능 평가 (Estimation of Concrete Durability Subjected to Freeze-Thaw Based on Artificial Neural Network)

  • 할리오나;허인욱;최승호;김강수
    • 한국구조물진단유지관리공학회 논문집
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    • 제27권6호
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    • pp.144-151
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    • 2023
  • 이 연구에서는 동결융해 작용을 받는 다양한 콘크리트 배합에 대한 실험결과를 수집하여 데이터베이스를 구축하였다. 이를 바탕으로 동결융해 작용을 받는 콘크리트의 인공지능 기반 내구성능 평가모델을 개발하였으며, 회귀분석을 통해 상대동탄성계수 추정식을 도출하였다. 제안된 인공신경망 모델의 오류율과 결정계수는 각각 약 10.4%와 0.7이었으며, 회귀분석 추정식도 유사한 결과를 나타내었다. 따라서, 제안된 인공신경망 모델 및 회귀분석 추정식은 다양한 배합의 동결융해 작용을 받는 콘크리트에 대한 상대동탄성계수를 추정하는 데에 활용될 수 있을 것으로 판단된다.