CURRENT PRACTICE SHEETS: PROPERTIES OF CONCRETE: PLASTIC CRACKING

The formation and prevention of plastic settlement cracking which occurs in columns, deep beams or walls, and shrinkage cracking, which is found in flat exposed slabs, is discussed. Both types of cracking are associated with bleeding of concrete which is also examined. Plastic cracking occurs where the settlement of the mix after compaction is impeded by reinforcement or the shape of the section. It can only be avoided by an improved mix design or by re-vibration of the concrete after placing. Because plastic settlement cracks usually stop at the steel causing the restraint, structural integrity is not normally lost. It is recommended that the cracks be sealed to prevent corrosion of the reinforcement. The most important factor affecting plastic shrinkage cracking is the rapid drying out of the concrete surface when the rate of evaporation exceeds the rate of bleeding. Methods of preventing plastic shrinkage cracking are examined and it is concluded that the best way is to cover the concrete with polythene sheeting almost immediately after placing and compaction. /TRRL/

  • Availability:
  • Corporate Authors:

    Cement and Concrete Association

    Wexham Spring
    Slough SL3 6PL, Buckinghamshire,   England 
  • Authors:
    • Turton, C D
  • Publication Date: 1978-7

Media Info

  • Features: Figures; References;
  • Pagination: p. 29-30
  • Serial:
    • CONCRETE
    • Volume: 12
    • Issue Number: 7
    • Publisher: THE CONCRETE SOCIETY
    • ISSN: 0010-5317

Subject/Index Terms

Filing Info

  • Accession Number: 00184431
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Jan 13 1979 12:00AM