AN INVESTIGATION OF THE DELAY PERIOD AND RELATED FACTORS IN STEAM-CURED CONCRETE

THE EFFECT OF VARIATIONS OF TIME AND TEMPERATURE IN THE STEAM-CURING CYCLE ON CONCRETES CONTAINING CEMENTS OF DIFFERENT SETTING RATES IS EVALUATED IN TERMS OF 1-DAY STRENGTH. THE OPTIMUM DELAY PERIOD FOR A GIVEN CONCRETE WAS CORRELATED TO THE PROCTOR PENETRATION TEST, AND THE EFFECT THE TYPE OF CEMENT AND DIFFERENT FACTORS OF A STEAM-CURING PROCEDURE HAVE ON THE LENGTH OF THE DELAY PERIOD WERE DETERMINED. SOME IMPORTANT CONCLUSIONS DRAWN FROM THIS INVESTIGATION WERE /1/ THE OPTIMUM DELAY PERIOD/ WAS 100 PERCENT OF THE INITIAL SET TIME FOR FAST AND MEDIUM SETTING CEMENTS /TYPES III AND II/. FOR SLOW SETTING CEMENTS /TYPE II WITH RETARDER/ IT WAS 75 PERCENT, /2/ AT THE OPTIMUM DELAY PERIOD, NO SIGNIFICANT DIFFERENCE IN STRENGTH OF CONCRETE USING TYPE III CEMENT WAS FOUND FOR MAXIMUM CURING TEMPERATURES OF 140, 160, AND 180 DEGREES FAHRENHEIT. CONCRETE USING TYPE II CEMENT, WITH AND WITHOUT RETARDER, THE STRENGTH INCREASED WITH AN INCREASE IN MAXIMUM CURING TEMPERATURE, /3/ AT THE OPTIMUM DELAY PERIOD, RATES OF TEMPERATURE RISE OF 40, 60, AND 80 DEGREES F PER HOUR HAD NO SIGNIFICANT EFFECT ON STRENGTH, /4/ FOR TYPE III CEMENTS, INCREASING THE GYPSUM CONTENT TO 7 PERCENT INCREASED STRENGTH 1,000 TO 1,500 P.S.I., /5/ HIGH GYPSUM CEMENT MIXTURES PRODUCED OPTIMUM STRENGTH WITH DELAY PERIOD OF 100 PERCENT OF INITIAL SET, AND /6/ FOR HIGH GYPSUM CEMENT MIXTURES, STEAM CURING REDUCED EXPANSION AT 450 DAYS BY 100 PERCENT AS COMPARED TO CONTINUOUS MOIST CURING. THIS WAS APPROXIMATELY THREE TIMES THAT OF THE MIXTURE CONTAINING THE CEMENT AS RECEIVED.

  • Supplemental Notes:
    • Hpr-1/27/, 0161 /STATE/
  • Corporate Authors:

    Virginia Highway Research Council

    Charlottesville, VA  United States 
  • Authors:
    • Brown, H E
  • Publication Date: 1965-4

Subject/Index Terms

Filing Info

  • Accession Number: 00211997
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 1 1994 12:00AM