Image Analysis of Plastic Shrinkage Cracking in High Strength Concrete Containing Hybrid Fibre Enforcement

High strength concrete (HSC) may be susceptible to plastic shrinkage cracking due to its reduced bleeding capacity and increased autogenous shrinkage. Fiber reinforcement has been proposed as one solution to mitigate plastic shrinkage cracking. In order to determine the benefits of fiber reinforcement, experimental procedures are needed to quantify crack width reduction. The majority of current techniques used to assess cracking in concrete utilize manual crack observation and measurement, which may be tedious and subject to operator bias. This paper describes a systematic approach to accurately characterize the plastic shrinkage cracking pattern (width, distribution, and frequency) that develops in a fiber reinforced concrete. This test procedure uses a retrained slab specimen with a stress riser that amplifies the potential for plastic shrinkage cracking. The concrete slabs were exposed to a drying environment for the first 6 hours. At an age of 24 hours, images were acquired along the cracking path. Cracks were extracted from the acquired images through gray level intensity thresholding to create binary images that were used to describe cracked and uncracked region. The crack widths were obtained by subtracting the binary crack image from a prepared grid mask that consisted of horizontal lines at standard uniformly spaced locations. A statistical analysis of the crack width at various locations was performed and a modified Weibull distribution was used in order to describe the results.

Language

  • English

Media Info

  • Media Type: Print
  • Features: References; Tables;
  • Pagination: pp 209-218
  • Monograph Title: Role of Concrete in Sustainable Development

Subject/Index Terms

Filing Info

  • Accession Number: 01010871
  • Record Type: Publication
  • ISBN: 0727732471
  • Files: TRIS
  • Created Date: Nov 28 2005 12:04PM