• 제목/요약/키워드: Civil & Environmental Engineering

검색결과 14,740건 처리시간 0.041초

Microbial Ecology of Emerging Contaminant Bioremediation

  • Park, Joon-Hong;Rhee, Ju-Hyoung;Oh, Hyang-Kyun;Ahn, Chang-Hoon;Oh, Jae-Il;Rittmann, Bruce
    • 한국미생물학회:학술대회논문집
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    • 한국미생물학회 2008년도 International Meeting of the Microbiological Society of Korea
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    • pp.86-88
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    • 2008

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Nondestructive detection of crack density in ultra-high performance concrete using multiple ultrasound measurements: Evidence of microstructural change

  • Seungo Baek;Bada Lee;Jeong Hoon Rhee;Yejin Kim;Hyoeun Kim;Seung Kwan Hong;Goangseup Zi;Gun Kim;Tae Sup Yun
    • Computers and Concrete
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    • 제33권4호
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    • pp.399-407
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    • 2024

  • This study nondestructively examined the evolution of crack density in ultra-high performance concrete (UHPC) upon cyclic loading. Uniaxial compression was repeatedly applied to the cylindrical specimens at levels corresponding to 32% and 53% of the maximum load-bearing capacity, each at a steady strain rate. At each stage, both P-wave and S-wave velocities were measured in the absence of the applied load. In particular, the continuous monitoring of P-wave velocity from the first loading prior to the second loading allowed real-time observation of the strengthening effect during loading and the recovery effect afterwards. Increasing the number of cycles resulted in the reduction of both elastic wave velocities and Young's modulus, along with a slight rise in Poisson's ratio in both tested cases. The computed crack density showed a monotonically increasing trend with repeated loading, more significant at 53% than at 32% loading. Furthermore, the spatial distribution of the crack density along the height was achieved, validating the directional dependency of microcracking development. This study demonstrated the capability of the crack density to capture the evolution of microcracks in UHPC under cyclic loading condition, as an early-stage damage indicator.

  • https://doi.org/10.12989/cac.2024.33.4.399 인용

A coupled wind-vehicle-bridge system and its applications: a review

  • Cai, C.S.;Hu, Jiexuan;Chen, Suren;Han, Yan;Zhang, Wei;Kong, Xuan
    • Wind and Structures
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    • 제20권2호
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    • pp.117-142
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    • 2015

  • The performance of bridges under strong wind and traffic is of great importance to set the traveling speed limit or to make operational decisions for severe weather, such as controlling traffic or even closing the bridge. Meanwhile, the vehicle's safety is highly concerned when it is running on bridges or highways under strong wind. During the past two decades, researchers have made significant contributions to the simulation of the wind-vehicle-bridge system and their interactive effects. This paper aims to provide a comprehensive review of the overall performance of the bridge and traffic system under strong wind, including bridge structures and vehicles, and the associated mitigation efforts.

  • https://doi.org/10.12989/was.2015.20.2.117 인용 KSCI