Akademska digitalna zbirka SLovenije - logo
ALL libraries (COBIB.SI union bibliographic/catalogue database)
  • Large ring test for evaluation of restrained shrinkage cracking [Elektronski vir] : calibration and experimental trial
    Xu, Zhongyu ...
    The durability of shotcrete tunnel linings is significantly affected by restrained shrinkage cracking. Given the unique characteristics of shotcrete applied in tunnel linings, especially when dealing ... with accelerated shotcrete containing reinforcement fibres, it is necessary to upscale the ring test commonly used. This paper presents a comprehensive experiment using large ring tests with cast concrete to investigate the impact of upscaling ring test geometry. The two ring specimens demonstrated comparable cracking age (22 days) and strain measured in the steel ring, suggesting that consistent results can be obtained through the proposed instrumentation, calibration, and correction methods. Moreover, the estimated induced tensile stresses of the concrete rings (2.8 and 2.7 MPa) are slightly lower than the predicted tensile strength (3.3 MPa) at the age of cracking, which indicates that some driving forces contributing to restrained shrinkage cracking were not indicated in the strain gauge readings. Furthermore, the study identified multi-crack formation and additional potential causes for crack initiation, which include self-restraint due to the moisture gradient in the vertical direction, deflection of the concrete ring caused by its self-weight, and friction on the contact surface of the support. Therefore, optimising the geometry of the ring specimens and the apparatus is imperative to minimise additional driving forces and unmeasurable restraints for crack initiation, especially when employing the stress rate method to assess cracking potential.
    Source: Advances in Civil Engineering (Online) [Elektronski vir]. - ISSN 1687-8094 (Vol. 2024, issue 1, [article no.] 698625, 5. Apr. 2024, str. 1-18)
    Type of material - e-article ; adult, serious
    Publish date - 2024
    Language - english
    COBISS.SI-ID - 201974787

    Link(s):

    https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/6698625
    DiRROS - Digital repository of Slovenian research organizations
    DOI

Shelf entry