SPLICES IN TENSILE REINFORCING BARS

EVALUATION IS BEING MADE OF VARIOUS METHODS OF CONNECTING TENSILE REINFORCING BARS IN REINFORCED CONCRETE CONSTRUCTION. A SERIES OF 122 DIFFERENT BAR SAMPLES WERE PREPARED AND TESTED TO FAILURE. THE DEFORMED BAR SIZES WERE NOS. 9, 10, 11, AND 14S FOR MATERIAL HAVING A NOMINAL YIELD STRENGTH OF 40,000 PSI /ASTM-A15 AND ASTM-A408/ AND A NOMINAL YIELD STRENGTH OF 60,000 PSI /ASTM-A432/. EIGHT DIFFERENT SPLICING SYSTEMS WERE STUDIED PLUS A SERIES OF CONTROL BARS /CONTINUOUS BARS WITHOUT ANY SPLICES/. STRESS- STRAIN DIAGRAMS ARE INCLUDED FOR ALL SAMPLES THAT YIELDED SUFFICIENT DATA. THE MOST PROMISING TYPES OF SPLICING DEVICES WERE SELECTED FOR FLEXURAL TESTS. EACH BEAM WAS REINFORCED IN THE BOTTOM WITH A SINGLE NO. 11 SIZE /ASTM-A15/ DEFORMED REINFORCEMENT BAR. THE BEAMS WERE TWELVE FEET IN LENGTH AND HAD CROSS SECTIONS 8 INCHES WIDE BY 12 INCHES DEEP. A TOTAL OF FOUR DIFFERENT SPLICING DEVICES WERE STUDIED IN THIS SERIES PLUS ONE BEAM WHICH CONTAINED A SIMILAR CONTINUOUS REINFORCING BAR /WITHOUT A SPLICE/ FOR CONTROL PURPOSES. THE RESEARCH RESULTS INDICATED THAT THERE WAS NO EQUIVALENT SUBSTITUTE FOR A CONTINUOUS BAR IN A MEMBER WITHOUT SACRIFICING SOME ULTIMATE CAPACITY AND STIFFNESS. AT POINTS WHERE A SPLICE MUST BE USED, GREATER DEFLECTION AND REDUCED ULTIMATE CAPACITY SHOULD BE RECOGNIZED BY THE DESIGNER. THE LAP DISTANCE REQUIRED BY THE 1961 AASHO SPECIFICATIONS SHOULD BE INCREASED TO 25 BAR DIAMETERS. IF A LAP SPLICE IS NOT FEASIBLE, A SPLICE CONSISTING OF A SLEEVE WITH METAL FILLER WAS THE NEXT MOST SUITABLE METHOD FOR SPLICING TENSILE REINFORCING BARS. THE ADDITION OF STIRRUPS IN THE LAP ZONE, AT A SPACING OF NOT MORE THAN ONE-HALF THE DEPTH OF THE MEMBER ADDS APPROXIMATELY 60 PERCENT TO THE STRENGTH OF A LAP JOINT WITHOUT INCREASING THE LAP DISTANCE REQUIRED.

• Supplemental Notes:
  • Hpr 1/1/, 64-06-2
• Corporate Authors:

  University of Oklahoma, Norman

  660 Parrington Oval
  Norman, OK  United States  73019-0390
• Authors:
  • Segner, E P
• Publication Date: 1965-8

Subject/Index Terms

• TRT Terms: Bars (Building materials); Beams; Construction; Deformation curve; Evaluation; Failure; Flexural strength; Joining; Lap joints; Material reinforcement; Methodology; Reinforced concrete; Samples; Splicing; Stirrups; Systems; Tensile properties; Testing
• Uncontrolled Terms: Tensile
• Subject Areas: Bridges and other structures; Construction; Highways;

Filing Info

• Accession Number: 00207758
• Record Type: Publication
• Source Agency: Bureau of Public Roads /US
• Files: TRIS
• Created Date: Nov 1 1994 12:00AM