TO EVALUATE METHODS AND/OR DEVELOP IMPROVED METHODS FOR THE MEASUREMENT OF CERTAIN PROPERTIES OF CONCRETE

PREVIOUS METHODS USED TO MEASURE THE CEMENT, WATER AND AIR CONTENTS OF FRESH PORTLAND CEMENT WERE STUDIED AND THE MOST PRACTICAL WAY FOR DETERMINING THESE CONSTITUENTS ACCURATELY IN THE FIELD WERE SELECTED AND STUDIED. TYPICAL CONCRETE SAMPLES WERE TESTED AND SHOWN TO BE UNSATISFACTORY FOR THE ACCURATE MEASUREMENT OF CEMENT AND WATER CONTENT PROBABLY DUE TO VARIANCE IN THE PERCENTAGE OF MORTAR IN THE SAMPLES. HOWEVER, IT WAS SHOWN THAT A MORTAR SAMPLE OBTAINED BY VIBRATING CONCRETE THROUGH A NO. 4 SIEVE COULD BE USED TO DETERMINE THE THREE CONSTITUENTS ACCURATELY AND A TESTING TUBE WAS DEVELOPED WHICH PERMITTED THE MEASUREMENT OF THE THREE CONSTITUENTS FROM THE SAME VIBRATED MORTAR SAMPLE. THE CEMENT WAS MEASURED USING GRAVIMETRIC TECHNIQUES, THE WATER BY DILUTION WITH ISOPROPYL ALCOHOL AND THE AIR USING VOLUMETRIC PROCEDURES. METHODS FOR DETECTING THE CONCRETE COVER OVER REINFORCING STEEL WERE ALSO INVESTIGATED AND THE MAGNETIC METHOD WAS RECOMMENDED AS THE MOST FEASIBLE APPROACH. A MAGNETIC DETECTION DEVICE CALLED A PACHOMETER WAS EVALUATED AND PROVED A USEFUL AND ACCURATE INSTRUMENT FOR MEASURING THE CONCRETE COVER OVER STEEL REINFORCEMENT."

• Supplemental Notes:
  • Summary of PROGRESS, JUN 67, PP 66-73, 6 FIG, 2 TAB

Subject/Index Terms

• TRT Terms: Air content; Alcohols; Cement content; Dilution; Exploration; Gravimeters; Magnetic detectors; Magnetic induction; Material reinforcement; Measuring instruments; Moisture content; Mortar; Portland cement concrete; Vibration; Volumetric analysis
• Old TRIS Terms: Cover; Magnetic methods of exploration
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00212538
• Record Type: Publication
• Files: TRIS
• Created Date: Jan 24 1994 12:00AM