TESTS OF REINFORCEMENT SPLICES FOR CONTINUOUSLY-REINFORCED CONCRETE PAVEMENT

LAP SPLICES IN REINFORCEMENT FOR CONTINUOUSLY-REINFORCED CONCRETE PAVEMENTS WERE TESTED UNDER LONGITUDINALLY-APPLIED STATIC AXIAL TENSILE LOADING TO FAILURE. LABORATORY TESTS WERE MADE TO DETERMINE THE LENGTH REQUIRED FOR EFFECTIVE LAP SPLICES IN HIGH YIELD POINT DEFORMED BAR AND WELDED WIRE FABRIC REINFORCEMENT FOR CONTINUOUSLY-REINFORCED CONCRETE PAVEMENTS. DEFORMED BAR REINFORCEMENT WAS TESTED FOR SIX DIFFERENT SPLICES AND A CONTROL SET HAVING FULL-LENGTH REINFORCEMENT. WELDED WIRE FABRIC WAS TESTED WITH FIVE DIFFERENT SPLICES AND CONTROLS. OBSERVATIONS WERE MADE FOR OPENINGS OF THE PREFORMED CRACK UNDER LOAD, TOGETHER WITH THE OCCURRENCE AND OPENING OF ADDITIONAL CRACKS AND THE MODE OF FAILURE. RESULTS WERE EVALUATED IN TERMS OF SEVERAL CRITERIA THAT ARE SIGNIFICANT TO THE FUNCTION OF REINFORCEMENT IN CONTINUOUSLY-REINFORCED PAVEMENT. HORIZONTAL LONGITUDINAL CRACKS OCCURRED IN THE PLANE OF THE REINFORCEMENT IN SPECIMENS REINFORCED WITH DEFORMED BARS . SUCH CRACKING ORIGINIATED AT TRANSVERSE CRACKS IN THE UNSPLICED PORTIONS OF THE TEST SPECIMENS WHEN STEEL STRESSES REACHED 50 KSI OR GREATER WITH CRACK OPENINGS OF 0.015 TO 0.029 IN. THESE LONGITUDINAL CRACKS ARE INDICATIONS OF BOND FAILURE IN REGIONS WHERE THE TENSILE STRESS IN THE STEEL DECREASES SHARPLY IN THE LONGITUDINAL DIRECTION FROM THE HIGH VALUES AT THE TRANSVERSE CRACK. THE HIGH TENSILE STRESS GRADIENT REQUIRES HIGH BOND STRESSES IN THESE REGIONS. WHEN BOND FAILURE OCCURS, THE TENSILE STRESS GRADIENT MUST DECREASE, AND THE STRAIN IN A GREATER LENGTH OF STEEL CONTRIBUTES TO MARKED INCREASES IN TRANSVERSE CRACK OPENING. LONGITUDINAL CRACKING FROM THE PREFORMED CRACK IN THE SPLICE APPEARED AT ABOUT THE SAME LOADS AS THE FIRST NATURAL TRANSVERSE CRACK. IN THE LONGER SPLICES, HOWEVER, THESE LONGITUDINAL CRACKS WERE SHORT AND DID NOT PROGRESS FURTHER UNTIL MANY ADDITIONAL TRANSVERSE CRACKS HAD FORMED. LARGE OPENINGS OF TRANSVERSE CRACKS, EXCEPT AT FRACTURE OF SHORTER SPLICES, DID NOT OCCUR UNTIL THE REINFORCEMENT YIELDED. SUCH LARGE OPENINGS WERE PRECEDED BY THE DEVELOPMENT OF MANY TRANSVERSE CRACKS. CRACKS AT SPLICES DO NOT OPEN AS WIDE AS CRACKS AT THE END OF SPLICES OR IN UNSPLICED REINFORCEMENT BECAUSE THERE IS TWICE AS MUCH STEEL IN THE SPLICE AREA.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/hrr/1964/60/60-007.pdf
• Supplemental Notes:
  • 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:
  • Lepper Jr, Henry A
  • Kim, Jai B
• Publication Date: 1964

Media Info

• Media Type: Print
• Features: Figures; Tables;
• Pagination: pp 116-139
• Monograph Title: Rigid Pavement Design 1963
• Serial:
  • Highway Research Record
  • Issue Number: 60
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Continuously reinforced concrete pavements; Cracking; Deformed bars; Evaluation; Failure; Laboratory tests; Length; Material reinforcement; Mode S; Splicing; Static loads; Tension; Testing; Welded wire fabrics
• Uncontrolled Terms: Lap splices; Observation
• Old TRIS Terms: Axial tension; Static loading
• Subject Areas: Construction; Highways; Pavements;

Filing Info

• Accession Number: 00214410
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Mar 24 1994 12:00AM