Title: Some Observations of the Strengths
of Large Reinforcing Bars
Author(s): William L. Gamble
Publication: Journal Proceedings
Appears on pages(s): 31-35
Keywords: bars: reinforced concrete: reinforcing steels;strains : strength: stresses: stress-strain relationships:tensile stress: tests: yield strength.
The results of full-section tests of 181 reinforcing bars, # 14 and # 18, ordered as ASTM A 615, Grade 60, are presented and discussed. Two brands of steel were included in the tests. It was found that many samples failed to meet the specification requirements. For example, many of the #I4 bars of Steel No. I failed to meet the ultimate stress requirement of 90 ksi, and the statistical distribution of test results suggests a complete lack of quality control. Nearly all of the # I8 bars of Steel No. 2 failed to meet the required yield stress of 60 ksi, with the average of thirty tests being 55.1 ksi. All of the bars of Steel No. 2 exhibited a well defined flattopped yield plateau in the stress-strain relationship, whicle most of the bars of Steel No. 1 yielded graduslly, and reached the required yield stress at a strain of approximately 0.005.