Title:
Epoxy-Coated Reinforcement Under Repeated Loading
Author(s):
D. B. Cleary and J. A. Ramirez
Publication:
Structural Journal
Volume:
90
Issue:
4
Appears on pages(s):
451-459
Keywords:
bond (concrete to reinforcement) coatings; cyclic loads; deformed reinforcement; epoxy resins; fatigue; materials; lap connections; splicing; structural design; Structural Research
DOI:
10.14359/3923
Date:
7/1/1993
Abstract:
Because epoxy coatings applied to reinforcement are known to reduce the bond strength of the reinforcement, 23 beams with splices placed in a constant moment region were subjected to repeated loading and then tested to failure to compare the service and ultimate load behavior of beams with coated and uncoated reinforcement. The repeated loading consisted of one million or five million cycles in the service load range. Splitting cracks formed at a lower load in beams with epoxy-coated reinforcement than in beams with uncoated reinforcement. In general, deflections, crack widths, and reinforcement stresses were larger in beams with epoxy-coated reinforcement during service loading. The differences in crack widths, deflections, and bar stresses in beams with coated and uncoated reinforcement were reduced with repeated loadings. Failure-bond stress ratios ranged from 0.82 to 0.96, with an average of 0.88. Differences in the behavior of beams with coated and uncoated reinforcement are attributed to a larger friction component of the bond mechanism with uncoated reinforcement.