METHODS OF ANALYSIS OF HARDENED CONCRETE

THIS RESEARCH WAS ACCOMPLISHED THROUGH SIX SEPARATE SUBSTUDIES, NAMELY: (1)"DEVELOPMENT OF AN AUTOMATED LINEAR TRAVERSE DEVICE FOR MEASURING THE COMPONENTS OF HARDENED CONCRETE." THIS DEVICE, SIMILAR TO THAT OF THE PORTLAND CEMENT ASSOCIATION, WAS FOUND TO HAVE THE FOLLOWING ADVANTAGES OVER PREVIOUS DEVICES: RESOLUTION UP TO FIVE TIMES BETTER, SPEED AT LEAST EIGHT TIMES BETTER, COEFFICIENT OF VARIATION ABOUT ONE-THIRD OF MANUAL OPERATION, REDUCED OPERATOR FATIGUE, AND REDUCED DATA PROCESSING TIME. (2) "DETERMINATION OF WATER/CEMENT RATIO." THE ANALYTICAL METHOD SUGGESTED BY AXON IS NOT RECOMMENDED, SINCE IT IS SHOWN THAT AT LEAST 40 SPECIMENS ARE REQUIRED TO PRODUCE STATISTICALLY SIGNIFICANT VALUES OF THE WATER/CEMENT RATIO AND OF THE CEMENT FACTOR. (3)"AIR VOID STUDIES." DIFFERENT AIR- ENTRAINING ADMIXTURES WERE FOUND TO PRODUCE SIGNIFICANTLY DIFFERENT AIR VOID SYSTEMS. IT WAS ALSO SHOWN THAT TRAVERSE LENGTHS CAN BE GREATLY REDUCED. (4)"EFFECTIVENESS OF CURING COMPOUNDS." CURING COMPOUND APPLICATION RATES OF AS LITTLE AS ONE-HALF THE PENNSYLVANIA DEPARTMENT OF HIGHWAYS SPECIFICATIONS WERE SHOWN TO BE AS EFFECTIVE IN PROMOTING CURING AS WERE HEAVIER APPLICATIONS. A SIMPLE, INEXPENSIVE FIELD CURING-GAGE WAS DEVELOPED WHICH SHOWS WHETHER THE CONCRETE IS BEING PROPERLY CURED. (5)"PILOT STUDY ON DEICER SCALING MECHANISM IN HARDENED CONCRETE." THE STUDY SUPPORTS THE THESIS THAT ADSORPTION OF MOLECULAR DIPOLES (DEICER SALTS) MAY BE AT LEAST CONTRIBUTORY TO DEICER SCALING. (6) "MOISTURE DISTRIBUTION IN A PAVEMENT SLAB." BY THE USE OF REMOVABLE DISKS, CUT FROM A PAVEMENT, IT WAS SHOWN THAT MOISTURE DISTRIBUTION VARIED IN A PREDICTABLE MANNER. /BPR/

  • Corporate Authors:

    Pennsylvania State University, University Park

    Pennsylvania Transportation Institute, Transportation Research Building
    University Park, PA  United States  16802

    Pennsylvania Department of Highways

    400 North Street
    Harrisburg, PA  United States  17120-0095

    Bureau of Public Roads /US

    400 7th Street, SW
    Washington, DC  United States  20590
  • Authors:
    • Larson, T D
    • Cady, P D
    • Browne, F P
    • Carrier, R E
    • Lowry, L L
  • Publication Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 00212069
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS
  • Created Date: Apr 16 1970 12:00AM