DEVIATIONS IN THE LOCATION OF REINFORCEMENT

AN INVESTIGATION WAS CONDUCTED TO DETERMINE THE SIZE OF DEVIATIONS IN THE PLACING OF BAR REINFORCEMENT, THEIR IMPORTANCE FOR SAFETY AND THEIR CAUSES. MEASUREMENTS ON PARALLEL-FACED FLOOR SLAB UNITS WERE MADE WITH THE AID OF A MEASURING FRAME. FOR BEAMS A SIMILAR MEASURING FRAME WAS USED, ITS LOCATION ON THE BEAM BEING DETERMINED RELATIVE TO THE CENTER LINE OF THE BEAM SECTION, DEFINED AS A LINE THROUGH THE CENTER OF THE TOP SIDE AND THE CENTER OF THE UNDERSIDE. AN ELECTROMAGNETIC COVER METER WAS USED TO DETERMINE THE LOCATION OF REINFORCEMENT BARS. X-RAY PHOTOGRAPHY WAS USED ALSO TO DETERMINE LOCATION OF REINFORCEMENT. LOCATION OF REINFORCEMENT IN WIRE-REINFORCED SECTIONS WAS DETERMINED BY SAWN CROSS-SECTIONS. THE MAGNITUDE OF VARIATIONS IN THE EFFECTIVE DEPTH WAS FOUND TO BE DEPENDENT ON THE METHODS OF MANUFACTURE. THEIR EFFECT ON DEVIATIONS IN THE ULTIMATE STRENGTH IS DETERMINED BY A GIVEN EQUATION. IN THE CASE OF INSITU FLOOR SLABS THE DEVIATIONS IN EFFECTIVE DEPTH ARE PRIMARILY RELATED TO DELIBERATE FAULT IN THE COVER THICKNESS. GREATER DEVIATIONS ARE REVEALED IN THE LOCATION OF TOP-EDGE REINFORCEMENT AND FOR LOWER-EDGE REINFORCEMENT. TOLERANCE FOR COVER, AND TOTAL AND EFFECTIVE DEPTH ARE DISCUSSED. PREFABRICATION GIVES OPPORTUNITIES TO REDUCE THE VARIATIONS IN COVER AND IN TOTAL DEPTH. MEASUREMENTS IN THE FORMWORK PRIOR TO POURING CAN ELIMINATE IMPORTANT CAUSES OF VARIATIONS.

  • Supplemental Notes:
    • No 40, 62 PP, FIGS, 8 REF, 2 APP
  • Authors:
    • JOHANSSON, A
    • Warris, B
  • Conference:
  • Publication Date: 1969

Subject/Index Terms

Filing Info

  • Accession Number: 00209159
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 20 1970 12:00AM