Title:
Lap Splices Anchored by Headed Bars
Author(s):
M. Keith Thompson, Antonio Ledesma, James O. Jirsa, and John E. Breen
Publication:
Structural Journal
Volume:
103
Issue:
2
Appears on pages(s):
271-279
Keywords:
anchorage; lap splice; reinforcement; strut.
DOI:
10.14359/15185
Date:
3/1/2006
Abstract:
The anchorage behavior of headed reinforcement in lap splices was studied experimentally. Observations of cracking behavior, strain measurements of reinforcement, and strength are reported. The behavior of unconfined laps is compared to confined laps. The behavior of nonheaded and headed bar laps is compared. Bar stresses are compared with a proposed model for bearing capacity at the head. Test results suggest that noncontact lap splices should be modeled using a truss mechanism with diagonal compression struts between opposing bars. Under such a model, the capacity of the lap is determined by an anchorage length that is defined by the intersection points of the diagonal struts. Using this model, the anchorage behavior of headed bars is similar to previously reported results from CCT node tests wherein anchorage consisted of bond and head bearing components. Overall results demonstrate that headed reinforcement can significantly reduce the required lap length of spliced reinforcement.