An accelerated-curing method that offers the possibility of forecasting the 28-day strength of concrete 48 hours after sampling was evaluated in the field. The method consists of casting and curing the concrete in styrofoam molds and has the following advantages over conventional accelerated-curing methods: (a) There is no change in the sampling and testing procedures normally used for the standard 28-day test, (b) the test is done during normal working hours, (c) no special heating or curing equipment is needed, (d) the concrete sample is protected from large curing-temperature variations that may occur during handling and transportation from the field to the laboratory, (e) the test cylinder of green concrete is protected from rough-handling damage, and (f) the technician is not exposed to injury by heat. More than 1,300 cylinders of paving and structural concrete, produced by 4 suppliers, were tested. The study showed that (a) there is a good correlation between 48-hour and 28-day test results, (b) the gain in strength at 48 hours is more than 60 percent of the 28-day strength, (c) a different 48-day to 28-day strength regression equation was found for each concrete supplier, and (d) the reliability of the strength test results of cured samples obtained by using the expanded polystyrene mold method is of the same order as that obtained by more elaborate accelerated-curing methods.

Media Info

  • Media Type: Print
  • Features: Appendices; Figures; References; Tables;
  • Pagination: pp 50-60
  • Monograph Title: Recent developments in accelerated testing and maturity of concrete
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00131692
  • Record Type: Publication
  • ISBN: 0309024668
  • Files: TRIS, TRB
  • Created Date: Jun 5 1976 12:00AM