Online SEM investigation of Microcrack Characteristics of Concretes at Various Temperatures

Until recently, little information has been available on the microcrack initiation and propagation behavior of high-performance concrete (HPC) at high temperature. This article reports on a study that characterizes microcracking nucleation and evolution for two types of concretes at different temperatures by in situ observations with scanning electron microscope. The authors also investigated the effect of microstructure and thermal energy on the microcracking of these concretes. Nondestructive evaluations of large-scale cracking, such as delaminations and spalling, are not addressed here. The study results indicated that the thermal energy plays an important role in microcracking and propagation of these concretes and showed that there are different fracture types with changing the microstructure of concretes. The authors conclude that the mechanical properties of type M concrete (mortar intermixed with sands) are better than those of type C concrete (not intermixed with sands), not only at room temperature but also at high temperature. Most of the nucleated microcracks in cement paste mortar are distributed along the applied loading direction, and the crack opening displacement in the loading direction is greater than that in the transversal direction.

  • Availability:
  • Authors:
    • Wang, Xi-Shu
    • Wu, Bi-Sheng
    • Wang, Qing-Yuan
  • Publication Date: 2005-7

Language

  • English

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Filing Info

  • Accession Number: 01002294
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 22 2005 6:52AM