ANCHORAGE DEVICES FOR LARGE DIAMETER REINFORCING BARS

Results of nineteen pullout tests conducted on #18, #14 and #11, Grade 60 steel reinforcing bars (ASTM A615-68) to evaluate end anchorage provided by an attached steel end-plate are reported. The effects of group action and low cycle dynamic loading are also reported. Short embedment lengths for anchored bars resulted in greater loaded-end slips than those realized by unanchored bars embedded in accordance with current allowable bond stresses. These slips, however, were less than the "critical" value of 0.010 of an inch at an applied steel stress of 24 kips per square inch. The anchor plate design utilizing shallower reinforcing steel embedment reduced the ductility of the system, at stress levels exceeding yield stresses, by limiting the length of bar available for plastic elongation after the occurrence of bond breakdown. The use of an anchorage device on bars with short embedment lengths served to increase ultimate strength capability to that of a fully embedded, unanchored bar. Visible concrete crack patterns were not influenced by the use of anchor plates. Group-action test results indicated greater slip values at values at given stress levels when compared with single bar tests. Multiple bar pullout tests need to be performed on unanchored bars before the group-action phenomenon can be better evaluated. /FHWA/

Media Info

  • Pagination: 63 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00097645
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • ISBN: CA-DOT-6626-1-73-30
  • Contract Numbers: D-4-99
  • Files: TRIS, USDOT, STATEDOT
  • Created Date: Sep 30 1975 12:00AM