DETECTION OF CONCRETE DETERIORATION UNDER ASPHALT OVERLAYS BY MICROSEISMIC REFRACTION

NONDESTRUCTIVE TESTING OF EXISTING HIGHWAYS AND STRUCTURES OFFERS ECONOMIC ADVANTAGES OVER METHODS THAT REQUIRE DEFACEMENT AND REPAIR, OR INTERRUPTION OF NORMAL SERVICE. CONCRETE SLABS OVERLAIN BY ASPHALTIC SURFACE COURSES, AND THUS NOT VISIBLE, PRESENT A MONITORING PROBLEM. ON BRIDGE DECKS AND SIMILAR EXPOSED LOCATIONS, CONSIDERABLE SLAB DETERIORATION CAN OCCUR WITHOUT PRODUCING EVIDENCE AT THE ASPHALT SURFACE. UNTIL RECENTLY, TEST PROCEDURES WERE LIMITED TO CORE SAMPLING, OR REMOVAL OF ASPHALT FOR INSPECTION. BOTH ARE COSTLY. A METHOD IS PRESENTED FOR DETERMINATION OF ASPHALT THICKNESS AND ESTIMATION OF CONCRETE STRUCTURAL SOUNDNESS BY MEASUREMENT OF THE DIRECT AND REFRACTED MICROSEISMIC WAVE VELOCITIES PRODUCED BY LOW ENERGY HAMMER IMPACTS ON THE MATERIALS SURFACE. THICKNESS IS DETERMINED BY SEISMIC REFRACTION FORMULA WHILE CONCRETE CONDITION IS ESTIMATED BY COMPARISON OF THE MEASURED VELOCITY IN THE CONCRETE WITH STANDARD VELOCITY OF CONCRETE HAVING KNOWN PROPERTIES. THEORETICAL BASIS FOR THE METHOD, DETAILED PROCEDURES FOR FIELD TESTS, AND FIELD AND LABOR- ATORY TEST INSTRUMENTS ARE DESCRIBED.

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/hrr/1966/146/146-004.pdf
• Supplemental Notes:
  • Paper sponsored by Committee on Maintenance of Structures and presented at the 45th Annual Meeting. 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:
  • Phelps, Joseph M
  • Cantor, Theodore R
• Publication Date: 1966

Media Info

• Media Type: Print
• Features: Appendices; Figures; Photos; References;
• Pagination: pp 34-49
• Monograph Title: Pavement and bridge maintenance
• Serial:
  • Highway Research Record
  • Issue Number: 146
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Asphalt; Concrete; Elastic waves; Field tests; Formulas; Laboratory tests; Microwaves; Nondestructive tests; Refraction; Roads; Seismicity; Soundness test; Structures; Thickness; Velocity measurement
• Uncontrolled Terms: Seismic refraction
• Old TRIS Terms: Existing roads; Hammering; Soundness
• Subject Areas: Bridges and other structures; Highways; Maintenance and Preservation; Materials;

Filing Info

• Accession Number: 00212299
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Dec 12 1994 12:00AM