PREDICTION OF POTENTIAL STRENGTH OF CONCRETE FROM THE RESULTS OF EARLY TESTS

A SERIES OF 3 EXPERIMENTS WAS CONDUCTED TO INVESTIGATE THE PRACTICALITY OF USING EARLY TESTS OF CONCRETE CYLINDERS MADE AT THE JOB SITE AS A MEANS OF QUALITY CONTROL AND STRENGTH PREDICTION OF CONCRETE. THE EXPERIMENTS INCLUDED CONCRETE OF 3 CEMENT CONSTANTS, 3 BRANDS OF CEMENT, AND 4 METHODS OF CONDITIONING SPECIMENS PRIOR TO TESTING. THE TEST RESULTS, WHEN ANALYZED BY STATISTICAL METHODS, INDICATE A DEFINITE LINEAR RELATIONSHIP BETWEEN THE LOGARITHM OF THE MATURITY OF THE CONCRETE IN DEGREE-HOURS AND THE RELATIVE COMPRESSIVE STRENGTH. WHEN SPECIMENS WERE TESTED AT SPACED VALUES OF MATURITY, AN EQUATION CAPABLE OF PREDICTING THE 28-DAY STRENGTH OF CONCRETE TO WITHIN ABOUT 500 PSI WAS DERIVED. PREDICTED RESULTS ARE SUITABLE FOR CONSTRUCTING ONE-SIDED CONFIDENCE LIMITS FOR QUALITY CONTROL PURPOSES. IT WAS FOUND PRACTICAL TO CONSTRUCT A NOMOGRAPH TO EXPEDITE THE COMPUTATION OF PREDICTED VALUES. A LIMITED AMOUNT OF SIMULATION WAS CONDUCTED ON 8 SETS OF TEST CYLINDERS MADE AT THE JOB SITE AND TESTED AT 23 TO 42 HOURS OF AGE. THE AVERAGE DIFFERENCE BETWEEN THE PREDICTED 28-DAY STRENGTHS AND THE ROUTINE 28-DAY TEST RESULTS WAS ABOUT 300 PSI. PRACTICAL APPLICATION OF THIS METHOD REQUIRES THAT A DEFINITE EARLY TEST PROCEDURE BE ESTABLISHED AND THAT EQUATION CONSTANTS FOR COMMONLY USED CONCRETE MIXTURES BE ESTABLISHED BY EXPERIMENT USING THIS PROCEDURE. /AUTHOR/

Media Info

  • Media Type: Print
  • Features: Appendices; Figures; References; Tables;
  • Pagination: pp 25-35
  • Monograph Title: Concrete
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00214092
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Apr 23 1972 12:00AM