EVALUATION OF PULSE VELOCITY TESTS MADE BY ONTARIO HYDRO

THE SONISCOPE WAS DEVELOPED PRIMARILY AS A NON-DESTRUCTIVE METHOD FOR FOLLOWING THE CRACKING BEHAVIOR IN CONCRETE GRAVITY DAMS BY PULSE VELOCITY TECHNIQUES. INTERNAL CRACKS ARE DETECTED BY AN ABNORMAL INCREASE IN TRANSMISSION TIME AND/OR REDUCTION IN PULSE AMPLITUDE. THE DEPTHS OF SURFACE CRACKS ARE DETERMINED BY MEASURING THE TIME REQUIRED FOR A PULSE OF SOUND TO TRAVEL AROUND THESE CRACKS. SUBSEQUENTLY, A RELATIONSHIP WAS ESTABLISHED BETWEEN PULSE VELOCITY AND THE QUALITY OF CONCRETE WHICH HAS MADE IT POSSIBLE TO ASSESS THE RELATIVE CONDITION OF STRUCTURES. CONSEQUENTLY, HAVING ESTABLISHED DATUM PULSE VELOCITY MEASUREMENTS, THE PROGRESS OF DETERIORATION IN BOTH FIELD STRUCTURES AND LABORATORY SPECIMENS IS FOLLOWED BY REPETITIVE TESTS. WHILE NO WELL- DEFINED CORRELATION BETWEEN PULSE VELOCITY AND 28-DAY STRENGTH HAS BEEN ESTABLISHED AS YET BY THIS LABORATORY, THE SONISCOPE HAS BEEN USED TO SOME EXTENT TO FOLLOW STRENGTH DEVELOPMENT OF CONCRETE AT EARLY AGES. LIMITED SUCCESS WAS ALSO ACHIEVED IN USING PULSE VELOCITY TEHNIQUES TO STUDY THE SONISCOPE IS SUBJECT TO CERTAIN LIMITATIONS AND POSSIBLE ERRORS. KNOWLEDGE OF THESE SHOULD NOT DISCOURAGE ITS USE BUT PROVIDE A BETTER UNDERSTANDING OF THE APPARATUS AND THEREBY PERMIT A MORE INTELLIGENT INTERPRETATION OF RESULTS. PULSE VELOCITY IS FOUND TO INCREASE WHEN SPECIMENS ARE SATURATED AND A FURTHER SIGNIFICANT INCREASE IN VELOCITY IS OBSERVED WHEN THESE SPECIMENS ARE FROZEN. LARGE QUANTITIES OF REINFORCING STEEL NEAR AND PARALLEL TO THE TRANSMISSION PATH, ALSO INFLUENCE THE RESULTS OF PULSE VELOCITY MEASUREMENTS. THE BEST ASSURANCE FOR REDUCING THE POSSIBLE ERRORS TO A MINIMUM AND OBTAINING THE MOST FROM THE EQUIPMENT, IS A COMPETENT OPERATOR CAPABLE OF USING SOUND JUDGEMENT IN THE INTERPRETATION OF THE RESULTS. /AUTHOR/

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/hrbbulletin/206/206-001.pdf
• Supplemental Notes:
  • No 206, pp 1-13, 12 FIG, 2 TAB, 8 REF Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
• Authors:
  • Sturrup, V R
• Publication Date: 1959

Media Info

• Monograph Title: Effects of concrete characteristics on the pulse velocity
• Serial:
  • Highway Research Board Bulletin
  • Issue Number: 206
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Amplitude modulation; Concrete; Concrete curing; Concrete dams; Cracking; Depth; Errors; Evaluation; Nondestructive tests; Pulse modulation; Pulses; Reinforcing steel; Time; Transmissions; Velocity measurement
• Uncontrolled Terms: Concrete cracking; Pulse velocity tests
• Old TRIS Terms: Pulse amplitude modulation; Soniscope
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00213235
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Sep 12 1994 12:00AM