Early removal of side forms from concrete members may cause mechanical damage or lead to frost damage. Currently, achievement of a cube compressive strength of 5 N/sq mm is the criterion for avoiding such damage, but recent research indicates that the value may be reduced to 2 N/sq mm. Soffit forms may be removed when members have sufficient flexural strength to withstand self-weight of the concrete and other applied loads. In addition, deflections must not be excessive. Research has shown that the proportion of design load applied at early age should not exceed the proportion of design compressive strength achieved at the age in the member under consideration. The relationships between compressive strength and two parameters, maturity equivalent and equivalent age, are discussed. Equivalent age is shown to be useful for the prediction of strength from a known temperature history at early age when the compressive strength development is very sensitive to curing temperature. At later ages, maturity equivalent may be more suitable for prediction purposes. A method of prediction of temperature history in hydrating concrete members has been combined with these methods of prediction of compressive strength to determine the times at which formwork may be removed, based on the criteria described.

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 19-28
  • Monograph Title: Recent developments in accelerated testing and maturity of concrete
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00131689
  • Record Type: Publication
  • ISBN: 0309024668
  • Files: TRIS, TRB
  • Created Date: Jun 5 1976 12:00AM