Title:
Steel Reinforcing Bar Specifications in Old Structures
Author(s):
Gustav G. Erlemann
Publication:
Concrete International
Volume:
21
Issue:
4
Appears on pages(s):
49-50
Keywords:
deformation; reinforcing materials; reinforcing steels; strength; specifications
DOI:
Date:
4/1/1999
Abstract:
Rehabilitating sixty-year-plus aged reinforced concrete structures requires knowledge of the strength of the materials furnished during that era. Reinforcing bars manufactured during that period generally were Grade 33 (228 MPa) with various patented deformation patterns (ASTM A 15-11). During 1928 the U.S. Department of Commerce recommended standard bar sized, semi-standard deformations, and Grade 40 (276 MPa) minimum. In 1950, A 15 specified all reinforcing bars as round (#3 through #11) with A 305 deformation patterns. In 1964, A 408 added sizes #14S and #18S, and two strength levels: A 432 (Grade 60 - 414 MPa) and A 431 (Grade 75 - 517 MPa). Finally, during 1968, ASTM combined all previous reinforcing bar specifications into A 615.