• Title/Summary/Keyword: Mass concrete

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An Experimental Study on the Properties of Ultra Low Heat Mass Concrete Containing Limestone Powder (석회석미분말을 혼입한 초저발열 매스콘크리트의 특성에 관한 연구)

  • 하재담;김동석;김태홍;이종열;권영호
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10b
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    • pp.1175-1180
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    • 2000
  • Recently, the crack of concrete induced by the heat of hydration of cement is a serious problem for more greater, special and higher strength of concrete structures. The increasing concrete's temperature is mainly caused by the heat of hydration of cement and so, to control the thermal stress of concrete structure is desirable to use low heater material of hydration. There are many methods to diminish the increasing of concrete temperature such as using of low heat cement, addition of fly-ash, application of pre-cooling, etc., and in this study, we evaluate the heating and mechanical properties of ultra low heat mass concrete using Low Heat Portland(KS Type IV) cement with 30% of limestone powder. The results of this study will be applied to side wall and bottom of No. 15 and 16 of underground LNG tank in Inchon.

The Analysis of Cracks in PSC Girder Using High Flowing Concrete (고유동 콘크리트를 사용한 PSC 거더 균열 분석)

  • Lho, Byeong Cheol;Ahn, Gwang Su;Kwak, Kil Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.3
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    • pp.126-135
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    • 2013
  • Recently, mass concrete with high flowability are widely used to improve the quality and constructability in the longer span construction of prestressed concrete bridges, but it may induce nonstructural cracks due to the hydration heat and autogenous shrinkage etc. The stresses in concrete were evaluated by various experiments and numerical analysis. The tensile stress in mass concrete was increased in connection with the accumulation of hydration heat. Moreover, large amount of autogenous shrinkage from powder type admixture could add the tensile stress to mass concrete near anchorage zone. The tensile stresses in anchorage zone by heat and autogenous shrinkage exceeded the tensile strength of early stage of concrete, and small amounts of stress increasement were shown in other parts of PSC girder.

An intelligent cooling control system for mitigating the cracking risks of mass concretes during bridge construction

  • Ruinan An;Peng Lin;Daoxiang Chen;Jianshu Ouyang;Zichang Li;Zheng Zhang;Yuanguang Liu
    • Advances in concrete construction
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    • v.17 no.5
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    • pp.257-271
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    • 2024
  • During any construction involving mass concrete, it is crucial to control cracking during the placement and curing process. This study develops an intelligent cooling control system that regulates water temperature and flow based on concrete hydration heat, effectively preventing cracking in bridge construction. The system consists of hardware, a neural network-based control algorithm, and an information management system. An optimal cooling control strategy is proposed to dynamically regulate water flow and temperature, preventing cracking by utilizing real-time temperature data, target control curves, neural network algorithms, and cloud-based computing. The intelligent cooling control system has been successfully implemented in controlling cracking risks during bridge construction. It not only mitigates the risk but also provides a convenient management strategy for bridge construction projects. The optimal cooling control strategy ensures high accuracy and stability under unsupervised learning conditions. This intelligent cooling control system can be applied to similar constructions such as bridge, dam, and building that involve the use of mass concrete.