Title:
Truss Model for Tension Bars in Reinforced Concrete Beams: Tension-Tension-Compression Regions
Author(s):
Sung-Gul Hong
Publication:
Structural Journal
Volume:
93
Issue:
6
Appears on pages(s):
729-738
Keywords:
bond cutoff bond failure; bars embedment length; bond strength; diagonal tension failure; reinforced concrete beams; stirrup strength; structural
effects; theory of plasticity; truss model;
DOI:
10.14359/520
Date:
11/1/1996
Abstract:
A plane truss model for the design of reinforcing bars in negative moment regions is presented herein to clarify the effects of diagonal cracking, stirrup strength, bar embedment length, and beam depth on bond failure load. Understanding these aspects of bond in load transfer help to overcome the current empiricism in this area. The truss model is developed for the limit analysis capable of explaining failure modes involving bond strength that cannot be explained by current truss models. This study finds that the pullout length over which bond strength fully develops is lower than the whole embedment length in the negative moment region of RC beams, and bond failure is combined with diagonal tension failure at support. The model provides a rational design methodology and a basis for the revision of current design provisions regarding bar cutoff.