Strategies to Mitigate Cracking of Self-Consolidating Concrete

The efficiency of various strategies to reduce cracking of self consolidating, fiber-reinforced self-consolidating, and superworkable concretes (SCC, FR-SCC, and FR-SWC, respectively) designated for repair applications is discussed. The FR-SCC and FR-SWC mixtures were prepared with 0.5% and 0.75% fiber volume (Vf), respectively. Fiber-reinforced self-consolidating mortar (FR-SCM) with 0.8% and 1.4% Vf were also investigated. Of particular interest is the resistance to restrained shrinkage. In addition to the use of fibers, shrinkage mitigation measures included the use of shrinkage-reducing admixture (SA) and/or a calcium oxide-based expansive agent (EA). In total, 18 mixtures were investigated. Mono- and multifilament synthetic and steel fibers were employed. A fiber-reinforced conventional vibrated concrete (FR-CVC) made with 0.5% steel fibers was prepared as a reference mixture. For the self-consolidating mixtures, the highest resistance to restrained cracking was obtained with the FR-SCC made with steel fibers and EA that exhibited a time-to-cracking (tcr) in the restrained shrinkage ring test of 36 days (low cracking potential). Such concrete exhibited the narrowest crack width (wcr) of 85 µm (0.0033 in.), which was comparable to that of FR-CVC (80 µm [0.0031 in.]). For the other mixtures, tcr values ranged between 1 and 23 days, and wcr values between 90 and 210 µm (0.0034 and 0.0083 in.); the highest value was 285 µm (0.0111 in.) obtained for the SCC without fibers, EA, and SA. Empirical models were proposed to predict tcr and cracking potential as a function of elastic modulus and drying (and autogenous) shrinkage. The best relative overall performance was obtained for FR-SCC made with steel fibers and EA or SA, followed by FR-SCC made with synthetic fibers, then SCC and FR-SCM.

• Record URL:
  • https://doi.org/10.14359/51714463
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/13846872
• Supplemental Notes:
  • Abstract reprinted with permission from the American Concrete Institute.
• Authors:
  • Kassimi, Fodhil
  • Khayat, Kamal H
• Publication Date: 2019-5

Language

• English

Media Info

• Media Type: Web
• Pagination: pp 73-83
• Serial:
  • ACI Materials Journal
  • Volume: 116
  • Issue Number: 3
  • Publisher: American Concrete Institute (ACI)
  • ISSN: 0889-325X
  • Serial URL: https://www.concrete.org/publications/acimaterialsjournal.aspx

Subject/Index Terms

• TRT Terms: Admixtures; Cracking; Fiber reinforced concrete; Repairing; Self compacting concrete
• Subject Areas: Highways; Maintenance and Preservation; Materials; Pavements;

Filing Info

• Accession Number: 01714380
• Record Type: Publication
• Files: TRIS
• Created Date: Aug 22 2019 8:49AM