Title:
CCT Nodes Anchored by Headed Bars-
Part 1: Behavior of Nodes
Author(s):
M. Keith Thompson, Michele J. Ziehl, James O. Jirsa, and John E. Breen
Publication:
Structural Journal
Volume:
102
Issue:
6
Appears on pages(s):
808-815
Keywords:
anchorage; reinforcement; strut; ties
DOI:
10.14359/14788
Date:
11/1/2005
Abstract:
The anchorage behavior of headed reinforcement in compression-compression-tension (CCT) nodes was studied experimentally. Observations of cracking behavior and measurements of strains in ties and confining reinforcement, head slip, and node and strut capacities are reported. The behavior of unconfined nodes is compared with confined nodes. Insight into the stress state of the node is obtained through strain measurements along ties and along confining steel around the node. The strain data show node failure to be related primarily to anchorage of the tie bar. Additionally, the anchorage of headed reinforcement is explored. Headed reinforcement anchorage is shown to consist of bond and head-bearing components. These components develop in separate stages such that bond generally peaks and begins to decline before head bearing peaks. The two components do not achieve peak capacity simultaneously.